date: name: class: unit 2 blm 2-1 unit 2 summary · 11/4/2018 · identical to the parent. (5.2)...

DATE: NAME: CLASS:

UNIT 2 BLM 2-1

Unit 2 Summary

Copyright © 2007, McGraw-Hill Ryerson Limited, a subsidiary of the McGraw-Hill Companies. All rights reserved.

This page may be reproduced for classroom use by the purchaser of this book without the written permission of the publisher.

Goal • Use this summary to review the concepts in Unit 2, Reproduction.

Chapter 4 The nucleus controls the functions of life. Chromosomes found within the nucleus contain the genes that store the information to make proteins. (4.1)

Proteins control the activities of cells. (4.1) RNA carries the message out of the nucleus to the ribosomes, which function to make proteins. (4.1)

A gene mutation is a change in the order of the A, G, C, and T bases. (4.2) Gene mutations can have a positive, negative, or neutral effect on the individual. (4.2) Mutations can occur when DNA is being made or can be caused by mutagens. (4.2) Gene therapy attempts to correct gene mutations. (4.2)

Chapter 5 Mitosis is the basis of asexual reproduction. There are three stages to the cell cycle: interphase, mitosis, and cytokinesis. (5.1) There are four phases to mitosis: prophase, metaphase, anaphase, and telophase. (5.1) Checkpoint proteins instruct the nucleus whether to proceed through the cell cycle. (5.1) An error in a checkpoint protein can cause diseases such as cancer, which is the result of uncontrolled cell division. (5.1)

Asexual reproduction requires only one parent, and the resulting offspring are genetically identical to the parent. (5.2)

Types of asexual reproduction include: binary fission, budding, fragmentation, vegetative reproduction, and spore formation. (5.2)

Human-assisted plant and animal cloning methods can be used to save the genetic information of endangered species or to produce an organism with a desired trait. (5.2)

Chapter 6 Meiosis is the basis of sexual reproduction. Meiosis produces gametes with half the number of chromosomes as body cells. (6.1) In meiosis I, homologous chromosome pairs line up at the equator, separate, and then move to opposite poles of the cell. (6.1)

In meiosis II, chromosomes move to the equator and sister chromatids move to opposite poles of the cell. (6.1)

The process of meiosis creates variation in organisms because genetic information is shuffled during meiosis I. (6.1)

Chromosome mutations can occur during meiosis and can cause genetic disorders. (6.1) The three stages of sexual reproduction are mating, fertilization, and development. (6.2) For sexually reproducing plants and animals, there are two ways for a sperm cell and an egg cell to meet—through either internal or external fertilization. (6.2)

The early development of an organism takes place during a stage called embryonic development. (6.2)

Assisted reproductive technologies enable infertile couples to have children. These technologies have an impact on society (6.3)

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UNIT 2 BLM 2-2

Unit 2 Words to Know



Goal • Use this page to review the Unit 2 Words to Know.

Chapter 4

chromosome DNA (deoxyribonucleic acid) gene gene mutation gene therapy mutagen negative mutation neutral mutation nucleolus nucleus positive mutation protein

Chapter 5

asexual reproduction binary fission budding cancer cell cycle clone cytokinesis fragmentation interphase mitosis replication spindle fibres spore stem cell vegetative reproduction

Chapter 6

differentiation diploid number embryo embryonic development external fertilization fertilization gametes genetic diversity haploid number homologous chromosomes internal fertilization mating meiosis sexual reproduction zygote

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CHAPTER 4 BLM 2-3

Parts of the Cell



Goal • Review the parts of a plant cell and an animal cell.

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BLM 2-3 continued



What to Do

Label each cell part.

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CHAPTER 4 BLM 2-4

Functions of Cell Organelles



Goal • Review the functions of cell organelles.

What to Do

Complete the following chart on cell organelle functions before you read pages 122–124 in your student book. Then check your responses as you read. Add any new information you gain in your reading in another colour of pen or pencil.

Functions Cell Organelle

Before Reading After Reading

Cell membrane

Cell wall

Cytoplasm

Mitochondria

Chloroplast

Ribosome

Endoplasmic reticulum

Vesicles

Golgi body

Vacuole

Nucleus

Nuclear membrane

Nucleolus

Cell membrane

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CHAPTER 4 BLM 2-5

Cell Organelles



Goal • Review cell parts and functions.

What to Do

Complete the following table by filling in the correct cell part or function.

Cell Part Function

Gel-like material inside cells

Directs cell activities

Endoplasmic reticulum

Manufactures substances important for cell functions

Releases energy in the cell

Chromatin

Chloroplast

Stores water, food, and waste products

Golgi body

Digests wastes

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CHAPTER 4 BLM 2-6

Modelling DNA



Goal • Use these models of DNA to complete Activity 4-1C, Modelling DNA.

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BLM 2-6 continued



What to Do

• Develop your own model of DNA. Follow the instructions below. • The completed model should look like a ladder. Matched bases form the rungs. Besides being

shaped like a ladder, a real DNA molecule would be twisted like a spiral staircase.

Materials

• paper models • scissors

Safety

Be careful when handling sharp or pointed objects. Procedure

1. Cut out the nucleotide models. Cut only on solid lines. 2. Fit eight nucleotide molecules together in puzzle-like fashion to form a row. Use the

following sequence from top to bottom: • cytosine nucleotide • thymine nucleotide • guanine nucleotide • adenine nucleotide • guanine nucleotide • cytosine nucleotide • thymine nucleotide • adenine nucleotide

3. The above arrangement represents the left half of the ladder of DNA. Complete the right side of the DNA ladder by matching the shapes of the rungs. It may be necessary to turn molecules upside down in order to join certain base combinations.

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CHAPTER 4 BLM 2-7

Extracting DNA from Strawberries



Goal • Use this flowchart before you do Activity 4-1D to help you understand the procedure for DNA extraction.

What to Do

The first step in DNA analysis in a crime or genetics laboratory is DNA extraction. Read the Find Out Activity on page 153 of your student book, and then complete the flow chart below.

Take 1 frozen strawberry.

1. Put into a

2. Add

3. Seal the bag. Gently crush the contents. Keep at room temperature and wait ____ min.

4. Fill a test tube about _______ full of strawberry solution.

5. Pour the __________ rubbing alcohol or ethanol into a______________.

6. Slowly pour a _________ of the rubbing alcohol or ethanol

into the test tube until it is _______ full.

Observe the DNA. Record your observations.

(a) (b) (c)

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CHAPTER 4 BLM 2-8

Making Predictions about Mutations



Goal • Use this page to make predictions about mutations.

What to Do

Make predictions about what the following terms mean. Give an example if possible. Then read the student book pages 138–143. Confirm or correct your predictions.

Term Before Reading

What I Think the Term Means/Example

After Reading What the Term Means/Example

Positive mutation

Negative mutation

Neutral mutation

Mutagen

Gene therapy

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CHAPTER 4 BLM 2-9

Chapter 4 Quiz



Goal • Check your understanding of Chapter 4.

What to Do

Circle the letter of the best answer.

1. The function of the nucleolus is A. to protect the nucleus B. to protect the chromosomes C. to make ribosomes D. to make DNA

2. Which of the following organelles does not have a membrane? A. mitochondrion B. vesicle C. vacuole D. ribosome

3. Which one of the following statements is not true? A. A gene stores the information to make a particular protein. B. All the genes within the nucleus of a cell will be copied to make a protein at some time in the life cycle of a cell. C. Different types of cells in your body contain the same genetic information. D. Different proteins have different sequences of bases.

4. The function of the Golgi body is A. to receive vesicles from the endoplasmic reticulum B. to send vesicles to the endoplasmic reticulum C. to receive messages from the nucleus D. to send messages to the nucleus

5. Which of the following steps for the production of a protein is incorrect? A. The DNA message for a protein is copied into RNA. B. The nucleus receives a chemical signal to make a specific protein. C. The manufactured protein enters the endoplasmic reticulum. D. DNA leaves through the nuclear pore.

6. Chromatin is A. a substance that contains several molecules of DNA within each strand B. a substance within the nucleus that contains DNA and proteins C. a substance that unfolds before cell division D. a segment of DNA that codes for a particular protein

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BLM 2-9continued



7. A gene mutation is A. a change in the specific order of the A, G, C, and T bases that make up a particular protein B. a change in the specific order of the sugar and phosphates that make up a particular protein C. a substance that changes the DNA structure D. a substance that causes genes to be copied incorrectly

8. Gene therapy is not used as frequently as drug therapy or surgical therapies because A. the technique is too expensive B. viruses for the procedure are not easily available C. healthy genes are not easily available D. the healthy gene must be switched on in the correct cells

9. Cystic fibrosis is A. an example of a neutral mutation B. an example of a positive mutation C. an example of a negative mutation D. the result of the substitution for the base A for the T base in only one position on the gene

10. The white coat of the Spirit Bear is because of a A. positive mutation B. neutral mutation C. negative mutation D. gene therapy

Match the Term on the left with the best Descriptor on the right. Each Descriptor may be used only once.

Term Descriptor

_____ 11. mitochondria

_____ 12. chloroplast

_____ 13. nucleus

_____ 14. nucleolus

_____ 15. Golgi body

_____ 16. endoplasmic reticulum

A. sorts and packages proteins for transport

B. ribosomes attach here

C. produces sugar for cell

D. changes sugar into useful energy for cell

E. ribosomes made here

F. contains information to make proteins

G. surrounds the cell membrane

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BLM 2-9continued



17. Explain how the nucleus controls the activities within a cell.

_____________________________________________________________________________

_____________________________________________________________________________

_____________________________________________________________________________

18. What are three causes of gene mutations?

_____________________________________________________________________________

_____________________________________________________________________________

_____________________________________________________________________________

19. Construct a flow chart that outlines how a protein is made. Use the terms below. Use additional words to connect the terms.

DNA, endoplasmic reticulum, Golgi body, nuclear pore, ribosomes, RNA, vesicle

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CHAPTER 5 BLM 2-10

From One Cell to Many Cells



Goal • Use this chart to help you complete Find Out Activity 5-1A, From One Cell to Many Cells.

What to Do

Calculate how many skin cells will result from just 1 cell that continually divides during a period of 30 days.

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CHAPTER 5 BLM 2-11

Stages of the Cell Cycle



Goal • Use this page to help you learn about the stages of the cell cycle.

What to Do

Complete this worksheet while you read about the stages of the cell cycle. You do not have to add any notes to the shaded boxes.

Name of Cell Cycle Stage Cell Activities Nucleus Activities Interphase

Growth and preparation

Replication

Continued growth and preparation

Mitosis

Early prophase

Late prophase

Metaphase

Anaphase

Telophase

Cytokinesis

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CHAPTER 5 BLM 2-12

The Cell Cycle



Goal • Review terms and concepts about the cell cycle.

What to Do

Match the Statements on the left with the correct Phase on the right. Each Phase may be used more than once.

Statement Phase

_____ 1. nucleolus appears within each new nucleus

_____ 2. centromeres divide

_____ 3. chromosomes become visible

_____ 4. spindle fibres begin to form

_____ 5. DNA replicates

_____ 6. replicated strands move toward opposite poles

_____ 7. chromosomes form a line across the middle of the cell

_____ 8. nuclear membrane forms around each set of chromosomes

_____ 9. cell grows

A. prophase

B. metaphase

C. anaphase

D. telophase

E. interphase

10. Place a check mark ( ) under each phase in which you can see the structures listed in the

first column. Structures

Present Interphase Prophase Metaphase Anaphase Telophase

Nucleus

Nucleolus

Nuclear membrane

Chromatin

Chromosomes

Spindle fibres

11. Describe the end result of mitosis.

_____________________________________________________________________________

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CHAPTER 5 BLM 2-13

Steps of Mitosis



Goal • Identify the phases of mitosis.

What to Do

In the boxes below • name each phase of mitosis • draw what is happening in the phase • describe what is happening in the phase

Phase 1: _____________________________ Description: ________________________

___________________________________

___________________________________


___________________________________

___________________________________


___________________________________

___________________________________


___________________________________

___________________________________

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CHAPTER 5 BLM 2-14

Cell Growth and Division



Goal • Review your understanding of the phases of the cell cycle.

What to Do

Write the name of the stage of the cell cycle that corresponds to each event described below.

1. Centromeres divide. ________________

2. Centrioles move to opposite ends of the cell. ________________

3. Nuclear membranes form around each mass of chromosomes. ________________

4. Chromosome strands separate and move toward opposite ends of the cell. ______________

5. A copy of each chromosome is made. ________________

6. Cell membrane pinches together and the cytoplasm of the cell divides. _________________

7. The nuclear membrane disappears. ________________

8. Daughter cells form. ___________________

9. Double-stranded chromosomes line up in the centre of the cell. ________________ 10. It makes up most of a cell’s life. _________________

Short Answer

11. In mitosis, how many cells form from the original cell? _________________

DATE: NAME: CLASS:

CHAPTER 5 BLM 2-15

The Cell Cycle and Cancer



Goal • Use this page to help you learn about cancer, the uncontrolled growth of cells.

What to Do

Checkpoints in a bike race ensure that the athlete and the bike are in good condition to continue in the race. There are also checkpoints in the cell cycle. Predict the answer to questions below, then read pages 159–161 to check your predictions.

Questions Before Reading What I Think

After Reading What I Learned

Why is it important that there be checkpoints in the cell cycle?

What causes a cell to become cancerous?

How does a cancer cell look compared to a normal cell?

How might the cell cycle be related to cancer?

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CHAPTER 5 BLM 2-16

Factors That Affect Development of Cancer



Goal • Learn about risk factors for developing cancer.

Factor Effect

Alcohol • Linked to cancers of the mouth, larynx, throat, esophagus, and liver

Food • Obesity increases the risk of many cancers. • Salt-cured, smoked, and nitrite-cured foods are linked to cancers of the stomach and esophagus. • Additives and preservatives are linked to some cancers. • High-fat diets may contribute to the development of certain cancers .

Home • Exposure to materials made from manufactured fibres such as carpets, plastic, rayon, and insulation linked to cancer • Exposure to cleaners, paints, and other chemicals linked to cancer

Radiation • X rays, the Sun, and radon in cigarettes linked to cancer

Sunlight • Exposure to sunlight is considered a major cause of skin cancer.

Tobacco • Responsible for about 30 percent of all cancer-related deaths • Smoking is responsible for most cases of lung cancer. • Cause of mouth and throat cancer

Work • Exposure to chemicals such as chromate and asbestos increases risk.

What to Do

Choose and complete one of the following activities.

1. One of the biggest challenges in public health is preventing young people from starting smoking. Conduct a poll among students to determine whether or not they are aware of the health risks associated with smoking. Ask them to list any health risks they can think of. Keep track of how many risks each student can identify. Present your findings in chart form.

2. Find out what the Non-Smokers’ Rights Association has been doing to try to eliminate

smoking. Present your findings in an oral report. 3. Work with a partner and use information from the chart to design a healthy lifestyle for

youth. Present your findings in the form of a news bulletin.

DATE: NAME: CLASS:

CHAPTER 5 BLM 2-17

Observing the Cell Cycle in Plant Cells



Goal • Use this page to record your observations of onion root tip cell cycle stages for Conduct an Investigation 5-1C, Observing the Cell Cycle in Plant Cells.

What to Do

Using high power on your microscope, find an onion root tip cell at each of the following stages and draw the cell in the appropriate box. Label the chromosomes and spindle fibres.

Prophase

Metaphase

Anaphase

Telophase

Cytokinesis

Interphase

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BLM 2-17continued



What to Do

Collect the following data using the directions on pages 162 and 163 of your student book. Record the data collected in the chart below.

DATE: NAME: CLASS:

CHAPTER 5 BLM 2-18

Examining Ideas about Cloning



Goal • Use this page to help you examine ideas about cloning.

What to Do

Read the list of words, sentences, and phrases below, which all connect in some way to cloning. Cut out the phrases and organize the ideas to represent your understanding of these statements and how they fit together. Construct a graphic organizer to illustrate your answer.

Techniques of cloning Saves species close to extinction

A clone would have feelings and emotions identical to those of the donor

A clone would be the same age as the donor

Produces plants that produce high crop yields

Reproductive cloning

Produces an animal that has become extinct

Produces a copy of yourself so that you will be immortal

Produces another you so that there will be a supply of your organs in case any of your organs fail

Possible applications of cloning

Therapeutic cloning Produces organs for transplant

Produces copies of your skin cells to treat burns

Misconceptions about cloning

Cloning Produces copies of Albert Einstein or other famous people

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CHAPTER 5 BLM 2-19

New Plants from Cuttings



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CHAPTER 5 BLM 2-20

New Plants from Roots



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CHAPTER 5 BLM 2-21

New Plants from Stems



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CHAPTER 5 BLM 2-22

New Plants from Grafting



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CHAPTER 5 BLM 2-23

Comparing Reproductive and Therapeutic Cloning



Goal • Use this page to compare the similarities and differences between reproductive and therapeutic cloning.

What to Do

After reading pages 176–178 in the student book, construct a Venn diagram to compare reproductive and therapeutic cloning.

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CHAPTER 5 BLM 2-24

Determining the Best Conditions for Yeast Reproduction



Goal • Use this page to record your observations for Conduct an Investigation 5-2B, Determining the Best Conditions for Yeast Reproduction.

What to Do

Follow the directions on pages 179–181 in your student book to perform the experiment and record your data below.

Part 1 Observing Budding in Yeast

Draw your observations of the yeast under the microscope using high power in the circle at right.

Part 2 Observing the Effect of Nutrients

Flask Conditions Fermentation Observed

Carbon Dioxide Produced

(balloon circumference in cm)

A 0 g sucrose

B 5 g sucrose

C 30 g sucrose

D 50 g sucrose

Part 3 Observing the Effect of pH

Flask Conditions Fermentation Observed

Carbon Dioxide Produced

(balloon circumference in cm)

E 40°C + pH 3

F 40°C + pH 5

G 40°C + pH 7

H 40°C + pH 10

DATE: NAME: CLASS:

CHAPTER 5 BLM 2-25

Chapter 5 Quiz




What to Do


1. The three stages of the cell cycle in order are A. interphase, cytokinesis, and mitosis B. interphase, replication and cytokinesis C. cytokinesis, replication, and interphase D. interphase, mitosis, and cytokinesis.

2. The purpose of DNA replication is to

A. separate the DNA strands B. separate the contents of the cell’s nucleus C. pair new bases with bases on the original DNA D. make an identical copy of the DNA

3. Which of the following is the correct order of the stages of mitosis?

A. telophase, anaphase, metaphase, prophase B. anaphase, metaphase, prophase, telophase C. anaphase, prophase, metaphase, telophase D. prophase, metaphase, anaphase, telophase

4. How does the cell cycle differ in plants and animals?

A. In plants, the daughter cells are not identical to the parent. B. In plants, a cell plate forms between the daughter cells. C. In plants, there are no spindle fibres formed. D. In plants, the centrioles move to opposite poles.

5. Which of the following descriptions does not describe cancer cell growth?

A. Cancer cell growth is highly controlled. B. Cancer cell has large abnormal nucleus. C. Cancer cells move to new locations. D. Cancer cells are unspecialized.

6. Which of the following organisms is not matched with its method of asexual

reproduction? A. yeast, budding B. hydra, binary fission C. sea star, fragmentation D. bacteria, spores

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BLM 2-25continued



7. If one cell divided once every hour, how many cells would be produced after eight hours? A. 16 B. 32 C. 64 D. 256

8. Which of the following is a disadvantage of asexual reproduction?

A. Offspring are genetic clones. B. Many offspring are produced. C. Energy is not required to find a mate. D. Large colonies are produced.

9. Which of the following is not a method of vegetative reproduction?

A. forming bulbs B. forming sprouts C. forming runners D. forming spores

10. Which of the following are the correct steps in DNA replication?

A. 1, 2, 3, 4 B. 2, 4, 1, 3 C. 3, 2, 4, 1 D. 4, 2, 1, 3

1. Each side of the ladder is a template on which a new side forms. 2. Enzymes separate the DNA molecule. 3. New bases pair with bases on the original DNA strand. 4. The DNA molecule unwinds.

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BLM 2-25continued



Match each Term on the left with the best Descriptor on the right. Each Descriptor may be used only once.

Terms Descriptors

_____ 11. prophase

_____ 12. telophase

_____ 13. anaphase

_____ 14. cytokinesis

_____ 15. metaphase

_____ 16. interphase

A. nuclear membrane forms around chromosomes

B. chromosomes form a single line at cell equator

C. the two nuclei separate

D. chromosomes attach to spindle fibres at their centromeres

E. DNA replicates

F. sister chromatids move to opposite poles of the cell

G. the chromosomes dissolve 17. What are three requirements which must be met before a cell continues through the

cell cycle?

_____________________________________________________________________________

_____________________________________________________________________________

_____________________________________________________________________________

18. (a) How are binary fission and budding similar?

_____________________________________________________________________________

_____________________________________________________________________________

(b) How are binary fission and budding different?

_____________________________________________________________________________

_____________________________________________________________________________

19. Explain the disadvantages of asexual reproduction.

_____________________________________________________________________________

_____________________________________________________________________________

_____________________________________________________________________________

DATE: NAME: CLASS:

CHAPTER 6 BLM 2-26

Using DNA to Solve Crimes



Goal • Use this page to learn how DNA can be used to solve crimes.

What to Do

Tree theft is a serious problem in British Columbia. Catching a tree thief is a difficult task. Forensic techniques are available to help solve these types of crimes. Read the information below. Then answer the questions that follow.

The Crime Scene

The red cedar was over 60 m high. It had stood for 650 years in the cool, moist coastal forest near Bella Coola. When it was a young sapling, it was shaded by the ancient trees around it. As it grew, its drooping branches provided winter food for moose, elk, and deer. Hundreds of generations of squirrels had dined on its cones. For centuries, bald eagles, chickadees, tree swallows, spotted owls, and woodpeckers nested in its branches. In winter, raccoons made dens in the cavities of its trunk. The tree was not harmed by insects because it produced pungent oils that made it resistant to pests. For hundreds of years, local Aboriginal people had used bark from the ancient tree to make clothing.

The red cedar had narrowly escaped forest fires started by lightning many times through the centuries. Fire was its only enemy. The site where the cedar grew was in a natural area that was protected from forestry and development.

One day, however, people with chainsaws arrived at its site. Within hours, the red cedar had been cut down and taken from the forest. What remained in the forest was a huge stump three meters in diameter and a large pile of sawdust.

A forest ranger came upon the crime scene weeks later and reported the theft to the RCMP. When the officers arrived to investigate, they shook their heads sadly. The diameter of the red cedar trunk was the largest the officers had investigated yet. It had been weeks since the crime was committed, but there was still evidence remaining to be collected. The RCMP officers loaded the evidence in the van. They were determined to solve this case.

Tree thieves steal an estimated $150 million dollars of timber each year in British Columbia. Giant ancient cedars are becoming increasingly rare. Old-growth red cedar is a prime target because it is valued for its resistance to decay. Red cedar is used for house siding, decking, and shingles, and the old growth wood is highly sought after by violin and cello makers.

DATE: NAME: CLASS:

BLM 2-26continued



Questions

1. Imagine you are investigating this crime. Working with a partner, outline a description of the victim. Include the victim’s height, diameter, age, and location. Identify any other organisms of the forest that were affected by this crime and explain how they are affected.

2. What might be the motive for this crime? 3. List the steps or procedures that forensic specialists use to investigate any type of crime

scene. 4. Review your list and determine what evidence might be available at this crime scene. 5. Describe how this evidence might be collected. 6. Predict what the thieves might do with the stolen tree. 7. Determine how the evidence collected may be used to catch the thieves. 8. Compare your list and techniques to those of other biodetectives in the class.

What Did You Find Out?

1. (a) How did your forensic methods to solve this crime compare to other methods proposed by your classmates?

_____________________________________________________________________________

_____________________________________________________________________________

(b) What could you add to your methods to improve them?

_____________________________________________________________________________

_____________________________________________________________________________

2. What were key pieces of evidence needed to solve this crime?

_____________________________________________________________________________

_____________________________________________________________________________

3. How could sawmills be made accountable in identifying the source of the wood that they process?

_____________________________________________________________________________

_____________________________________________________________________________

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CHAPTER 6 BLM 2-27

How Variation Occurs in Meiosis



Goal • Review your understanding of how variation occurs in meiosis.

What to Do

1. Complete the concept map to connect ideas on variation in meiosis.

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CHAPTER 6 BLM 2-28

Gametes



Goal • Review your understanding of gametes.

What to Do

In the spaces provided, write the term from the list below that best completes the sentence. Terms may be used more than once. You will not need to use every term.

body cells, chromosomes, crossing over, egg cells, gametes, meiosis, mitosis, sperm cells

1. Organisms produce ___________________________ through mitosis. 2. The main job of ________________________ is to join together to produce a new organism. 3. In humans, _________________________ have 46 chromosomes. 4. Gametes are the only cells that are not produced by ___________________________. 5. ________________________________ are the female gametes. 6. ________________________________ are the male gametes. 7. __________________________________ contain the instructions that tell a cell how to develop.

In the space provided, answer the following question.

8. Describe the relationship between chromosome numbers in body cells and gametes.

______________________________________________________________________________

______________________________________________________________________________

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CHAPTER 6 BLM 2-29

Key Events in Meiosis



Goal • Review the steps of meiosis.

What to Do

Use the diagram to answer the questions that follow.

1. Each chromosome doubles itself, forming two identical copies, called sister chromatids. (a) How many chromosomes are in diagram 1? ______ (b) How many chromatids ? _______

2. The doubled chromosomes come together in matching pairs in diagram 2. Where do they line up? ___________________________________________________________________

3. (a) The chromosomes separate in diagram 3. Where are they pulled? ___________________ (b) Are the chromosomes that have been pulled all the same or are they different? _________

4. The first division of meiosis has occurred, and the cell has formed two new cells (diagram 4). What are the contents of these cells? ________________________________________________________

5. In diagram 5, the chromosomes again line up along the centre of each new cell. How does this step differ from diagram 2? ___________________________________________________

6. In diagram 6, the sister chromatids separate and move to opposite ends of the cell. How is this stage of meiosis very similar to mitosis? _________________________________________

7. (a) The cells divide in diagram 7. How many new cells are formed by meiosis? ____________ (b) Compared to the parent cell, how many chromosomes does a new cell have? ___________

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CHAPTER 5 BLM 2-30

Compare the Events of Meiosis and Mitosis



Goal • Use this page to compare the events of meiosis and mitosis.

What to Do

Study the diagrams of mitosis and meiosis in your student book. Use words and/or labelled drawings to compare the following events.

Meiosis I Mitosis

Prophase I Prophase (early and late)

Metaphase I Metaphase

Anaphase I Anaphase

Telophase I Telophase

Interkinesis Cytokinesis

DATE: NAME: CLASS:

BLM 2-30 continued



Meiosis II Mitosis

Prophase II Prophase (early and late)

Metaphase II Metaphase

Anaphase II Anaphase

Telophase II Telophase

Cytokinesis Cytokinesis

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CHAPTER 6 BLM 2-31

Compare the Results of Meiosis and Mitosis



Goal • Compare the results of mitosis and meiosis.

What to Do

Complete the chart and answer the questions that follow.

Comparing Meiosis and Mitosis Meiosis Mitosis

1. Type of cell undergoing reproduction

2. Number of chromosomes before cell begins to divide 4 4

3. Number of chromosome pairs in the original cell

4. Final number of chromosomes in each new cell at the end of division

5. Chromosome pairs in each new cell at end of division

6. Compare the location and arrangement of chromosomes in the cell during metaphase I in meiosis and metaphase in mitosis.

______________________________________________________________________________

______________________________________________________________________________

7. Compare the location and arrangement of chromosomes in the cell during anaphase I in meiosis and anaphase in mitosis.

______________________________________________________________________________

______________________________________________________________________________

8. How do the end results of meiosis and mitosis differ?

______________________________________________________________________________

______________________________________________________________________________

9. Predict what would happen if gametes were produced by mitosis rather than meiosis.

______________________________________________________________________________

______________________________________________________________________________

DATE: NAME: CLASS:

CHAPTER 6 BLM 2-32

Mitosis and Meiosis



Goal • Review your understanding of mitosis and meiosis.

What to Do

Match each of the following descriptions with the corresponding event depicted in the diagram below. Write the correct letter in each blank.

_________ 1. Chromatids are still joined in meiosis, but not in mitosis.

_________ 2. Chromatids separate.

_________ 3. Chromosomes double in both mitosis and meiosis.

_________ 4. Mitosis is complete, but another division is about to take place in meiosis. The chromosomes line up along the centre of the cell.

_________ 5. In meiosis, the chromosomes separate but chromatids remain joined. In mitosis, chromatids separate.

_________ 6. Chromosomes line up in pairs in meiosis but not in mitosis.

_________ 7. End products of meiosis

Short Answer

8. Use “haploid” and “diploid” to compare the end products of meiosis with the end products of mitosis. How do they differ?

_____________________________________________________________________________

_____________________________________________________________________________

DATE: NAME: CLASS:

CHAPTER 6 BLM 2-33

Gamete Summary



Goal • Summarize what you understand about gametes.

What to Do

1. Place a check mark ( ) to show which kind of cell has the trait listed in the first column.

Trait Sperm Cell Egg Cell Both Sperm Cells and Egg Cells

Has a tail

Has 23 chromosomes

Involved in fertilization

Formed in testes

Contains cytoplasm

Motile

Produced by meiosis

Formed in ovaries

Has a food reserve

Forms a zygote 2. Describe how a zygote is produced.

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

DATE: NAME: CLASS:

CHAPTER 6 BLM 2-34

Several Types of Chromosome Mutations



DATE: NAME: CLASS:

CHAPTER 6 BLM 2-35

Modelling How Variation Occurs in Meiosis



Goal • Use this chart to help you complete Investigation 6-1D, Modelling How Variation Occurs in Meiosis.

What to Do

Use pencil crayons to draw the chromosomes before and after crossing over occurs.

DATE: NAME: CLASS:

CHAPTER 6 BLM 2-36

Cell Reproduction



Goal • Review your understanding of mitosis and meiosis.

What to Do

Read the statements given below. If the statement is true, write “T” on the line in front of the statement. If it is false, write “F” and rewrite the statement to make it true. ____ 1. Gametes have twice as many chromosomes as other cells.

_________________________________________________________________________________

____ 2. Zygotes are produced by the union of sperm and egg cells.

_________________________________________________________________________________

____ 3. Meiosis may form egg cells.

_________________________________________________________________________________

____ 4. Gametes are formed during mitosis.

_________________________________________________________________________________

____ 5. Only a diploid zygote can function as the offspring’s first body cell.

_________________________________________________________________________________

____ 6. Four new cells are formed from each parent cell in meiosis.

_________________________________________________________________________________

____ 7. There are two cell divisions during mitosis.

_________________________________________________________________________________

____ 8. Haploid refers to the gametes of a cell with only one set of chromosomes.

_________________________________________________________________________________

____ 9. If a cell with six chromosomes undergoes mitosis, each new cell will also have six chromosomes.

_________________________________________________________________________________

_________________________________________________________________________________

DATE: NAME: CLASS:

CHAPTER 6 BLM 2-37

Critical Periods of Embryonic and Fetal Development



DATE: NAME: CLASS:

CHAPTER 6 BLM 2-38

Chapter 6 Quiz




What to Do


1. Which of the following is the correct order in sexual reproduction? A. meiosis, gamete, fertilization, embryo B. gamete, meiosis, fertilization, embryo C. fertilization, meiosis, gamete, embryo D. gamete, fertilization, meiosis, embryo

2. Mitosis is similar to meiosis II because

A. in both processes, the number of chromosomes is doubled B. in both processes, identical daughter cells are produced C. in both processes, sister chromatids separate and move to opposite poles D. in both processes, homologous chromosomes separate and move to opposite poles

3. Which of the following events occurs in mitosis only?

A. produces genetically different cells B. produces haploid cells C. cells divide two times D. produces genetically identical cells

4. Gamete formation in males is different than in females because

A. in males, meiosis begins before birth and stops until puberty B. in males, meiosis II occurs before meiosis I C. in males, there is equal distribution of cytoplasm into four cells D. in males, there is unequal distribution of cytoplasm into four cells

5. The difference between gene mutations and chromosomal mutations is that

A. a single gene mutation can affect many genes in the chromosomes B. gene mutations are the result of mutagens such as radiation C. chromosomal mutations affect the sequence of the bases D. chromosomal mutations can affect many genes in the chromosomes

6. A mutation that would be inherited must occur in a

A. skin cell B. egg cell C. muscle cell D. cancer cell

DATE: NAME: CLASS:

BLM 2-38 continued



7. Cow body cells have 60 chromosomes. How many chromosomes will be in a sperm cell following meiosis II? A. 30 B. 60 C. 120 D. 15

8. In the gastrula, cells in the mesoderm layer will become

A. kidneys B. skin C. lungs D. liver

9. What is the main advantage of sexual reproduction?

A. Very little energy is required to find a mate. B. Fewer offspring are produced. C. The embryo is protected from dehydration. D. The offspring are genetically different from the parents.

10. The procedure when a single sperm is injected into an egg cell is known as

A GIFT B. ICSI C. AI D. IVF


Term Descriptor

___ 11. prophase I

___ 12. telophase II

___ 13. anaphase I

___ 14. metaphase II

___ 15. anaphase II

___ 16. prophase II

A. the chromosomes form a single line at the equator

B. sister chromatids move to opposite poles of the cell

C. there is one chromosome of the homologous pair in each cell

D. homologous chromosomes pair up and non-sister chromatids exchange genetic material

E. a nuclear membrane forms around each set of chromosomes

F. independent assortment of chromosome pairs occurs

G. DNA replicates

DATE: NAME: CLASS:

BLM 2-38 continued



17. Explain how the events of sexual reproduction produce variation in a species.

_____________________________________________________________________________

_____________________________________________________________________________

_____________________________________________________________________________ 18. Explain how sexual reproduction by internal fertilization provides advantages over external

fertilization.

_____________________________________________________________________________

_____________________________________________________________________________

_____________________________________________________________________________ 19. What are three advantages of assisted reproductive technologies?

_____________________________________________________________________________

_____________________________________________________________________________

_____________________________________________________________________________

DATE: NAME: CLASS:

CHAPTER 6 BLM 2-39

Unit 2 Test



Goal • Test your understanding of Unit 2, Reproduction.

What to Do


1. A skin cell functions differently than a muscle cell because A. there are different genes in each cell B. there are different DNA molecules in each cell C. different proteins are made in each cell D. different genes are made in each cell

2. RNA is an important molecule in the cell because it

A. carries information from one generation to the next B. carries information from the cell to the rest of the body C. carries information from the ribosome to the nucleus D. carries information from the nucleus to the cytoplasm

3. If one side of a DNA molecule had the bases ACGTTGACT, the order of the bases on the

other side of the strand would be A. ACGTTGACT B. TGCAACTGA C. GTACCAGTC D. CGCAACTA

4. Which is not a use for gene therapy?

A. to clone an organism B. to replace a mutated gene with a healthy gene C. to deliver healthy genes using inactive viruses to treat cystic fibrosis D. to alter the immune system

5. Which of the following is not a step in DNA replication?

A. The DNA molecule unwinds. B. The steps of the DNA ladder break apart to form a template. C. The RNA is copied from the DNA molecule. D. The new side forms and A pairs with T and G pairs with C.

6. In the DNA sequence GACTGACTGACT, a mutation occurred and the piece of DNA

then contained the letters GACTTGACTGACT. What type of mutation is this an example of? A. deletion B. addition C. substitution D. translocation

DATE: NAME: CLASS:

BLM 2-39 continued



7. People with Down syndrome have A. 47 chromosomes in their karyotype B. 45 chromosomes in their karyotype C. three copies of chromosome 18 D. one copy of chromosome 21

8. The embryonic stage where the embryo cells are arranged into a hollow ball is called a

A. morula B. blastula C. gastrula D. fetus

9. Which event in prophase of mitosis is incorrect?

A. The nucleolus disappears. B. Centromeres pull apart. C. Spindle fibres form. D. Individual chromosomes attach to spindle fibres.

10. Which of the following best describes the events of anaphase 1?

A. Homologous chromosomes pair up at the equator. B. One chromosome from each homologous pair is at each pole of the cell. C. The centromere pulls apart, and the sister chromatids separate and are pulled to opposite poles by the spindle fibres. D. Homologous chromosomes attached to centromeres separate and are pulled to opposite poles by the spindle fibres.


Term Descriptor

___ 11. gametes ___ 12. mitosis ___ 13. ectoderm ___ 14. stem cells ___ 15. zygote ___ 16. meiosis ___ 17. diploid ___ 18. sexual reproduction ___ 19. endoderm ___ 20. independent assortment

A. two sets of chromosomes B. formed from the process of fertilization C. produces genetically different offspring D. these cells will form the lungs and liver E. specialized cells needed for reproduction F. the process where duplicated chromosomes

divide in two G. produces variation H. these cells will form the brain I. have the potential to become any type of cell J. process that produces gametes K. only one parent is required to produce offspring

DATE: NAME: CLASS:

BLM 2-39 continued



21. How does the nucleus control the functions of life? ____________________________________________________________________________________________

____________________________________________________________________________________________

____________________________________________________________________________________________ 22. Explain how the gene message creates a protein in the cell. ____________________________________________________________________________________________

____________________________________________________________________________________________

____________________________________________________________________________________________ 23. Why is interphase important for the cell and cell cycle? ____________________________________________________________________________________________

____________________________________________________________________________________________

____________________________________________________________________________________________ 24. (a) List three types of asexual reproduction.

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

(b) Provide an example of each type.

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________ 26. (a) What are mutations?

__________________________________________________________________________

__________________________________________________________________________

(b) How are mutations caused?

__________________________________________________________________________

__________________________________________________________________________

DATE: NAME: CLASS:

BLM 2-39 continued



27. Why may human-assisted plant and animal cloning methods be useful in the future? ____________________________________________________________________________________________

____________________________________________________________________________________________

____________________________________________________________________________________________ 28. Describe how the process of fertilization takes place within a flower. ____________________________________________________________________________________________

____________________________________________________________________________________________

____________________________________________________________________________________________ 29. What main events occur in fetal development within the first three months following fertilization? ____________________________________________________________________________________________

____________________________________________________________________________________________

____________________________________________________________________________________________ 30. What are three societal issues involving reproductive technology? ____________________________________________________________________________________________

____________________________________________________________________________________________

____________________________________________________________________________________________

DATE: NAME: CLASS:

CHAPTER 6 BLM 2-40

Making a Decision for Genetown Stakeholder List



Goal • Use this page to determine your stakeholder position for the Unit 2 Project.

What to Do

Choose one of the following roles to represent.

1. A patient who had unsuccessful stem cell treatment

2. An entrepreneur who wants to open a national umbilical cord bank and is willing to help fund this project

3. A 40-year-old person afflicted with Parkinson’s disease

4. A couple who have a child afflicted with leukemia. They have stored embryos at the in vitro clinic and they are hopeful that stem cell research will cure their afflicted child.

5. The child and caregiver of parents who both have Alzheimer’s disease

6. A representative of a drug company that wants to use stem cells to test drugs

7. A high school student who became a paraplegic following a skiing accident

8. A person who has heart cell damage following a heart attack

9. A politician who is looking out for public safety over economic gains

10. A member of the National Bioethics Society who questions if everyone will have equal access to stem cell treatment

11. A Right to Life advocate who believes that an embryo should receive the same respect before birth as it would if already born

12. A member of a couple who spent thousands of dollars for successful in vitro fertilization treatments. They now have two children but they have a lot of debts and would be willing to sell their remaining frozen embryos.

13. A local resident who is afraid that the research company is going to manufacture an army of human clones

14. A somatic cell nuclear transfer specialist

15. A doctor from the provincial children’s hospital

16. A concerned citizen who believes that this overseas company will obtain embryos illegally

17. A religious leader

DATE: NAME: CLASS:

BLM 2-40 continued



18. A researcher from the nearby university college who is studying the development of

humans from fertilized egg to adult

19. The director of the in vitro fertilization clinic in the city

20. The largest financial investor in Stem Cells Now

21. A director of the biotechnology department of the university college who hopes to attract world leaders in stem cell research to the province and to Genetown

22. A Genetown taxpayer

23. A local mall owner

24. The mayor who will conduct the meeting

25. A town council member who will listen to the viewpoints, then meet to vote and decide on the future of Stem Cells Now in Genetown



28. A patient who had a successful stem cell treatment

29. An unemployed but skilled worker who could work for Stem Cells Now

30. A construction contractor who would build the Stem Cells Now building

DATE: NAME: CLASS:

CHAPTER 6 BLM 2-41

Presentation Organizer



Goal • Prepare for a formal presentation to a committee.

What to Do

Use this page to organize your arguments.

My role _________________________________________________________________________

Props I will use ___________________________________________________________________

Arguments I will present

My arguments Support for my arguments

DATE: NAME: CLASS:

CHAPTER 6 BLM 2-42

Debate Procedures



Goal • Review and use the process of a formal debate.

Think About It

A formal debate has an orderly step-by-step procedure that is followed by people who take opposing or contradictory views of issues presented as resolutions. There can be four speakers, two for the resolution and two against. A debate chair introduces the resolution, rules, speakers, and the order in which the speakers present their views. The debate chair also announces the winner after taking a vote to determine which side supported its points better.

Speaker Time Job

Speaker #1 for the resolution

3 min • clarifies the resolution or issue • supports the resolution • often introduces a plan showing how the resolution could be implemented

Speaker #1 against the resolution

3 min • challenges the definitions, points, and evidence given by Speaker #1 for the resolution • offers points against the resolution • sums up why Speaker #1 was wrong or misguided and why the negative position is preferred

Speaker #2 for the resolution

3 min • counters the points given by Speaker #1 against the resolution • supports the good points made by Speaker #1 for the resolution • makes any new points

Speaker #2 against the resolution

3 min • makes any new points • counters specific points supporting the resolution • clarifies the position against the resolution

BREAK FOR UP TO THREE MINUTES

Speaker against the resolution

2 min • points out where speakers for the resolution have failed to prove their points • sums up the points made by the team against the resolution

Speaker for the resolution

2 min • points out why the resolution must succeed • makes a final review of the position for the resolution

DATE: NAME: CLASS:

CHAPTER 6 BLM 2-43

Unit 2 Review Concept Map



Goal • Use this concept map to complete question 1, Unit 2 Review, page 238 of BC Science 9.

UNIT 2 BLM 2-44

Unit 2 BLM Answers



BLM 2-5, Cell Organelles

Cell Part Function

Cytoplasm Gel-like material inside cells

Nucleus Directs cell activities

Endoplasmic reticulum Folded membrane that transports materials inside the cell

Ribosome Manufactures substances important for cell functions

Mitochondrion Releases energy in the cell

Chromatin Mass of dispersed genetic material

Chloroplast Contains chlorophyll, the pigment for photosynthesis

Vacuole Stores water, food, and waste products

Golgi body Stacks of sacs that package and transport proteins

Lysosome Digests wastes BLM 2-7, Extracting DNA from Strawberries

1. plastic bag 2. (a) 5 mL dish soap (b) 2.5 mL table salt (c) 25 mL tap water 3. 5 min 4. one-half 5. ice cold, graduated cylinder 6. layer, three-quarters BLM 2-8, Making Predictions about Mutations

Term Before Reading

What I Think the Term Means/Example

After Reading What the Term Means/Example

Positive mutation Students’ answers will vary.

A change in the DNA that produces a change that benefits the organism

Example: A few people are resistant to HIV infection.

Negative mutation

Students’ answers will vary.

A change in the DNA that produces a change that harms the organism

Example: Substitution of base A for T causes sickle cell anemia.

Neutral mutation Students’ answers will vary.

A change in the DNA that produces a change that neither benefits nor harms the organism

Example: Spirit Bear, since it has no natural predators

Mutagen Students’ answers will vary.

Substance that causes a mutation, such as asbestos, cigarette smoke, X rays

Gene therapy Students’ answers will vary.

Treatment used to correct gene mutations, such as treatment for cystic fibrosis

BLM 2-44 continued



BLM 2-9, Chapter 4 Quiz

1. C 2. D 3. B 4. A 5. D 6. B 7. A 8. D 9. C 10. B 11. D 12. C 13. F 14. E 15. A 16. B 17. The nucleus contains DNA, which carries the code to make and specific proteins, such as enzymes and

hormones that perform specific functions in the cell. 18. Three types of gene mutations are deletions, additions, and substitutions. 19. The chart should connect the terms in a similar way to the example below: DNA codes for a protein. The RNA message for a protein is copied from the DNA. RNA leaves through a nuclear pore. RNA goes to the ribosomes, and the protein is made. The protein enters the endoplasmic reticulum. A vesicle forms off the endoplasmic reticulum and goes to the Golgi body. The Golgi body repackages the protein for export out of the cell. BLM 2-11, Stages of the Cell Cycle

Name of Cell Cycle Stage Cell Activities Nucleus Activities

Interphase Longest stage of cell cycle

Cell carrying on its functions

Cell doubles everything in cytoplasm

DNA inside nucleus is replicated

Growth and Preparation Cell increases in size

Cell makes proteins

Organelles duplicate

Replication DNA inside nucleus is replicated

Continued Growth and Preparation

Cell gets larger

Cell makes proteins

Organelles duplicate

BLM 2-44 continued



Mitosis Shortest stage Contents of cell nucleus divides

Early prophase Spindle fibres begin to form and centrioles appear in animal cells

X-shaped chromosomes become visible Nucleolus disappears Nuclear membrane begins to break down

Late prophase Spindle fibres complete forming Chromosomes attach to spindle fibres

Nucleus no longer visible

Metaphase Spindle fibres pull chromosomes into a single line at equator


Anaphase Sister chromatids separate and move to opposite poles


Telophase One complete set of chromosomes now at each pole of the cell Spindle fibres disappear

Cytokinesis Two nuclei separated into two daughter cells Cell membrane pinches together to divide the cell’s cytoplasm and organelles

Nucleus now bound by membrane

BLM 2-12, The Cell Cycle

1. D 2. C 3. A 4. A 5. E 6. C 7. B 8. D 9. E

10. Structures Present Interphase Prophase Metaphase Anaphase Telophase

Nucleus

Nucleolus

Nuclear membrane

Chromatin

Chromosomes

Spindle fibres

11. Replicated DNA separates into two identical sets of DNA, one for each new cell’s nucleus. BLM 2-13, Steps of Mitosis

Description answers will vary. Suggested descriptions are given below.

Phase 1: Prophase

Nucleus and nuclear membrane disappear. Spindle fibres begin to form.

BLM 2-44 continued



Phase 2: Metaphase

Spindle fibres pull double-stranded chromosomes across the middle of the cell.

Phase 3: Anaphase

Spindle fibres pull centromeres apart. One of each of the replicated strands moves to opposite poles of the cell.

Phase 4: Telophase

One set of chromosomes is now at each pole of the cell. Spindle fibres disappear. A nuclear membrane re-forms around each set of chromosomes. BLM 2-14, Cell Growth and Division

1. anaphase 2. prophase 3. telophase 4. anaphase 5. interphase 6. cell division 7. prophase 8. cell division 9. metaphase 10. interphase 11. two cells BLM 2-15, The Cell Cycle and Cancer

Questions What I Think What I Learned

Why is it important that there be checkpoints in the cell cycle?

Students’ answers will vary. The cell will die if it divides without enough nutrients, or with too many DNA errors, or if the DNA did not replicate correctly.

What causes a cell to become cancerous?

Students’ answers will vary. A mutation can occur in a checkpoint protein, and then cell cycle control will be lost.

How does a cancerous cell look compared to a normal cell?

Students’ answers will vary. Cells grow in multilayers. The cells have large abnormal nuclei because the nuclei may be full of undivided chromosomes.

How might the cell cycle be related to cancer ?

Students’ answers will vary. With the loss of cell cycle checkpoints, the cell could undergo uncontrolled cell division.

BLM 2-23, Comparing Reproductive and Therapeutic Cloning

Reproductive cloning: produces a clone of an existing organism; the purpose is to clone an individual with desirable qualities

Both: types of human-assisted animal cloning; involve the transfer of a nucleus of one cell into enucleated egg cell Therapeutic cloning: produces a clone of an organ or tissue; the purpose is to correct health problems BLM 2-25, Chapter 5 Quiz

1. D 2. D

BLM 2-44 continued



3. D 4. B 5. A 6. B 7. D 8. A 9. D 10. D 11. D 12. A 13. F 14. C 15. B 16. E 17. Before a cell can continue through the cell cycle there must be enough nutrients to support cell growth, the DNA must be replicated, and the DNA should not be damaged. 18. (a) Binary fission and budding are both methods of asexual reproduction. (b) Differences are that binary fission occurs in unicellular organisms and budding can occur in both unicellular and multicellular organisms. Also, in binary fission one parent cell divides once into two same-sized daughter cells, whereas in budding there may be repeated cell divisions and an unequal-size outgrowth forms off the parent. 19. The main disadvantage of asexual reproduction is that the offspring are genetic clones. If the conditions change or a disease appears it could wipe out the whole population. BLM 2-26, Using DNA to Solve Crimes

1. Students’ answers may vary depending on their responses and those of other students. 2. The key pieces of evidence could have been materials left behind by the thieves that contained fingerprints or DNA, including tools, cigarette butts, and tire tracks. The tree stump leaves the tree ring pattern which could be matched to the stolen log; however, thieves are cutting a piece off the stump so this type of match is not simple. However, sawdust from the tree stump could be matched for DNA with sawdust from cut wood brought to a nearby sawmill. 3. A small sample from each log could be saved, and an inventory of the source of each log could be kept. BLM 2-27, How Variation Occurs in Meiosis

1. meiosis I 2. meiosis II 3. homologous chromosomes 4. sister chromatids 5. crossing over, non-sister 6. homologous chromosomes BLM 2-28, Gametes

1. body cells 2. gametes 3. body cells 4. mitosis 5. egg cells 6. sperm cells 7. chromosomes 8. Gametes have half the number of chromosomes as body cells.

BLM 2-44 continued



BLM 2-29, Key Events in Meiosis

1. (a) 4 chromosomes (b) 8 chromatids 2. Across the centre of the cell 3. (a) To opposite ends of the cell (b) Different 4. Each cell has one chromosome from each pair. Each chromosome is composed of sister chromatids 5. Chromosomes are not paired. 6. Sister chromatids separate as they do in mitosis. 7. (a) 4 new cells (b) Half the number of chromosomes BLM 2-30, Compare the Events of Meiosis and Mitosis Key

Meiosis I Mitosis

Prophase I Prophase (early and late)

• nucleolus disappears • nuclear membrane disappears • spindle fibres form • homologous chromosomes pair up and each attach to spindle fibres • non-sister chromatids exchange genetic material (crossing over)

• nucleolus disappears • nuclear membrane disappears • spindle fibres form • individual chromosomes attach to spindle fibres

Metaphase I Metaphase

• homologous chromosomes pair up at the equator • chromosomes form a single line at the equator

Anaphase I Anaphase

• spindle fibres contract and shorten • homologous chromosomes attached to centromeres separate and are pulled to opposite poles by the spindle fibres

• spindle fibres contract and shorten • the centromere pulls apart, and the sister chromatids separate and are pulled to opposite poles by the spindle fibres

Telophase I Telophase

• one chromosome from each homologous pair is at each pole of the cell • the spindle fibres disappear • the nucleolus appears within each nucleus • the nuclear membrane forms

• one complete set of chromosomes is now at each pole of the cell • the spindle fibres disappear • the nucleolus appears within each nucleus • the nuclear membrane forms

Interkinesis Cytokinesis

• cell divides in two (not genetically identical to parent cell) • cell will grow and make proteins like interphase in mitosis • no replication of DNA in this stage

• cell divides in two (genetically identical to parent cell) • cell will grow and make proteins like interphase in mitosis • DNA will replicate later in interphase

BLM 2-44 continued



Meiosis II Mitosis

Prophase II Prophase (early and late)



Metaphase II Metaphase

• X-shaped chromosomes form a single line at the equator

• X-shaped chromosomes form a single line at the equator

Anaphase II Anaphase

• spindle fibres contract and shorten • the centromere pulls apart and the sister chromatids separate and are pulled to opposite poles by the spindle

• spindle fibres contract and shorten • the centromere pulls apart, and the sister chromatids separate and are pulled to opposite poles by the spindle

Telophase II Telophase

• half of a complete set of chromosomes is now at each pole of the cell (one chromosome for each pair)• the spindle fibres disappear • the nucleolus appears within each nucleus • the nuclear membrane forms

• one complete set of chromosomes is now at each pole of the cell • the spindle fibres disappear • the nucleolus appears within each nucleus • the nuclear membrane forms

Cytokinesis Cytokinesis

• cell divides in two (total four daughter cells not genetically identical to parent) • cell will grow and make proteins like interphase in mitosis

• cell divides in two (genetically identical to parent) • cell will grow and make proteins like interphase in mitosis

BLM 2-31, Compare the Results of Meiosis and Mitosis

Comparing Mitosis and Meiosis Meiosis Mitosis

1. Type of cell undergoing reproduction gamete body cell

2. Number of chromosomes before cell begins to divide 4 4

3. Number of chromosome pairs in original cell 2 2

4. Final number of chromosomes in each new cell at the end of division

2

4

5. Chromosome pairs in each new cell at end of division none

2

6. In mitosis, chromosomes are not paired, but they do line up along the cell centre. In meiosis, chromosomes first line up and then become arranged along the cell centre. 7. The locations are the same, but in meiosis, in each pair of sister chromatids, the original and copy are still attached to each other.

BLM 2-44 continued



8. Mitosis produces two cells identical to the original one. Meiosis produces four cells, each with half the chromosomes of the original one. 9. The resulting organism would have twice the normal number of chromosomes. BLM 2-32, Mitosis and Meiosis

1. D 2. F 3. A 4. E 5. C 6. B 7. G 8. Student answers should include the following points. • Mitosis produces diploid cells, or body cells. • Meiosis produces haploid cells, or gametes. BLM 2-33, Gamete Summary

1. Trait Sperm Cell Egg Cell Both Sperm Cells

and Egg Cells

Has a tail

Has 23 chromosomes

Involved in fertilization

Formed in testes

Contains cytoplasm

Motile

Produced by meiosis

Formed in ovaries

Has a food reserve

Forms a zygote

2. A zygote is produced by the union of sperm and egg; the sperm fertilizes the egg. BLM 2-36, Cell Reproduction

1. False. Gametes have half as many chromosomes as body cells. 2. T 3. T 4. False. Gametes are formed during meiosis. 5. T 6. T 7. False. There is one cell division during mitosis. 8. False. During sperm cell production, four haploid sperm cells are produced. 9. T

BLM 2-44 continued



BLM 2-38, Chapter 6 Quiz

1. A 2. C 3. D 4. C 5. D 6. B 7. A 8. A 9. D 10. B 11. D 12. E 13. F 14. A 15. B 16. C 17. Variation is produced through independent assortment and crossing over in meiosis and the meeting of egg and sperm in fertilization. 18. Sexual reproduction by internal fertilization provides advantages since there is more protection for embryos and more parental care of offspring, and offspring are genetically different. 19. Answers should include: Some infertile couples are able to have a child. Couples can select embryos to exclude embryos with genetic defects. Parents trying to help cure a sick child can screen and select embryos for tissue matches. Extra embryos can be made available for stem cell research. BLM 2-39, Unit 2 Test

1. C 2. D 3. B 4. A 5. C 6. B 7. A 8. B 9. B 10. D 11. E 12. F 13. H 14. I 15. B 16. J 17. A 18. C 19. D 20. G 21. The nucleus contains the genes that store the information to make proteins, and proteins have many different functions within the cell such as to function as enzymes and hormones.

BLM 2-44 continued



22. The gene message creates a protein in the cell when the DNA is copied into RNA message. Then RNA leaves the nucleus through the nuclear pores in the membrane and RNA travels to the ribosome, where proteins are made. If proteins are to be shipped out of the cell, proteins enter the endoplasmic reticulum for transport. Vesicles form off the endoplasmic reticulum and travel to the Golgi body for repackaging before they leave the cell. 23. Interphase is important for the cell and cell cycle because this is when DNA is replicated. New organelles and chemicals are made in preparation for cell division. 24. Types of asexual reproduction are binary fission seen in bacteria or amoebas, budding seen in sponges or yeast, fragmentation seen in algae or sea stars, and spore formation seen in ferns and mosses. 25 Differences between mitosis and meiosis are: two daughter cells result from mitosis, four daughter cell from meiosis; the chromosome number is diploid or 2n following mitosis and is haploid or n following meiosis, the genetic information is the same in the daughter cells following mitosis, the genetic information is different in daughter cells following meiosis 26. Mutations are errors in the DNA caused by errors when the DNA replicates or caused by environmental mutagens such as X rays and chemicals. They can be errors in the bases within a gene or can be large chromosomal errors where whole pieces of chromosomes are lost, duplicated, or moved to another chromosome. 27. Human-assisted plant and animal cloning methods will be useful in the future to produce a greater food supply with pest-and drought-resistant crops, to grow organs for transplant, and to help maintain endangered species. 28. A flower is fertilized when the pollen, the male gamete, lands on the stigma of the flower and a pollen tube forms which delivers the sperm to the ovule or ovary which contains the egg and where fertilization takes place. 29. The main events in fetal development that occur within the first three months following fertilization are the formation of the brain and spinal cord; fingers appear; and eyes, kidneys, lung, liver, and muscles develop. 30. Answers may vary, but may include: that they may cause a slightly higher number of birth defects: what to do with leftover embryos; the issue of inequity, since some couples cannot pay for the procedure; and who the parents are.

date: name: class: unit 2 blm 2-1 unit 2 summary · 11/4/2018 · identical to the parent. (5.2)...

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