ACCELERATED BIOLOGY

Semester 1 Final Exam Review2012

SCIENTIFIC METHOD AND BIOCHEMISTRYCHAPTER 1 (OMIT 1:2)

CHAPTER 2

Unit 1

1. What are the 7 characteristics of life? Describe each and give an example of an organism and how it exhibits that

characteristic.

1. Cellular Organization – Made of 1 or more cells. Ex) A Bacterium is 1 cell and humans are composed of trillions of cells.

2. Reproduction – Sexual or asexual. Organisms make more of their own kind

3. Metabolism – Sum of all the chemical reactions carried out by an organism in order to obtain and use energy.

4. Homeostasis – Maintain a stable internal environment.5. Heredity – Pass on traits to their offspring. Ex) children

resemble their parents6. Responsiveness – Responding and adjusting to the

environment.7. Growth and development – Pass through stages of

development. Ex) Tadpole frog

2. Describe the parts of the Scientific Method.

1. Observation – Using your senses to study the world.2. Problem – Asking a narrow question based on specific

observations.3. Hypothesis – Educated guess to answer the problem.

1. Expressed as an If . . . Then statement

4. Experiment – Test of your hypothesis5. Data – Information you collect during an experiment

1. Qualitative – describe using words2. Quantitative – describe using numbers

6. Conclusion – State whether the data supports or refutes the hypothesis

(Our Pizza Has Extra Delicious Cheese)

3. Define: experimental variable, controlled variable, control group, experimental groups.

1. Experimental variable – The variable that is measured by the scientist; a.k.a the dependent variable

2. Controlled variable – Constants. Things that are the same for both the control and experimental groups.

3. Control group – Does NOT receive the variable; used as a comparison

4. Experimental group – Receives the variable

4. Describe the difference between bar graphs and line graphs.Explain a situation in which you’d use each.

1. Bar Graph – When you want to compare several things.

1. Line Graph – Change over time.

5. What are the 6 rules you must follow when making good graphs?

1. Independent variable on the x–axis2. Dependent variable on the y–axis3. Label axes4. Include units5. Title graph6. Use a ruler

 6. Read the following experiment & answer the questions

(if an answer doesn’t exist, make improvements).

Stewie wanted to see which detergent would make his favorite teddy bear (Rupert) the cleanest. He believed that “Nature’s Best”, an environmentally friendly product would work better than “Clean & Bright” which was the leading brand. First he stained the left arm of Rupert with a mixture of dirt, grape juice and Crayola markers. He then repeated the same procedure on Rupert’s right arm. Stewie then measured out the same amount of water and he proceeded to handwash the stains in a small basin scrubbing for 8 minutes using 10mLs of “Nature’s Best” on the left arm. The whole process was repeated using 10mLs “Clean & Bright” on the right arm.

 6. Read the following experiment & answer the questions

(if an answer doesn’t exist, make improvements).

• What was Stewie’s hypothesis?• IF I use both Nature’s Best and Clean & Bright

detergent to clean dirt, grape juice, and Crayola marker stains from my Teddy bear, THEN Nature’s Best will get my Teddy the cleanest.

• What was the independent variable?• Brand of detergent

• What was the dependent variable?• How clean Teddy’s arm was

 6. Read the following experiment & answer the questions

(if an answer doesn’t exist, make improvements).

• What were the constants (controlled variables) in this experiment• Same type of stain, amount of detergent, scrubbing time

• What was the control group?• Staining a portion of teddy and not scrubbing it clean.

• If Stewie was to graph the data, what would appear on the X axis• Brand of detergent

• Y axis?• % of stain removed

• What kind of graph is this?• Bar graph

7.

A scientist studied the effects of various water pH levels on the heartrate (heartbeats per minute) of a small crustacean called a Daphnia. He did this by putting Daphnia in solutions varying in pH solutions and counted the number of times their hearts beat in one minute.

• a. What would be the independent variable?• pH

• b. What would be the dependent variable?• Daphnia’s heartrate

7.

• Sketch a set up of the graph that could be made from his data. Be sure that your graph follows all the rules of “good graphs”

• d. Would it be a line graph or a bar graph? Why?• It shows the effect of the independent variable on the

dependent variable.

8. Explain the pH scale and numbering system used.Which numbers are considered acids? Bases? Neutral?

• Acids – 0 6.9

• Neutral – 7.0

• Bases – 7.1 14

9. List the 4 major biological compounds, their building blocks, their major functions, and 3 examples of each.

10. What is an organic compound? What elements do all organic compounds contain?

• All contain carbon atoms that are covalently bonded to others elements– typically hydrogen, oxygen, and other carbon atoms.

• Made from thousands or even hundreds of thousands of smaller molecules.

• Examples:• Carbohydrates• Lipids• Proteins• Nucleic Acids

11. Explain the difference between monosaccharides, disaccharides, and polysaccharides. Give an example of each.

• Monosaccharide – “Single sugar” Ex) glucose

• Disaccharide – “Double sugar”Ex) sucrose; table sugar (glucose + fructose = sucrose)

• Polysaccharide – “Many sugars” Ex) starch

 12. What is an enzyme? Give 3 examples of enzymes and state

their functions. Why are they an important part of our digestion?

• Enzymes are protein molecules. They speed up chemical reactions that would otherwise take a long time. This is called catalyzing the reaction.

1. Lactase breaks down lactose

2. Catalase breaks down Hydrogen Peroxide

3. Amylase breaks down starch

13. What is a substrate?

The substance that an enzyme break down.

14. Using the diagram below, explain the lock-and-key theory in the space below each graphic

14. Using the diagram below, explain the lock-and-key theory in the space below each graphic

• The shape of the enzyme perfectly fits the shape of its substrate• Like a lock and a key!

• Therefore, enzymes will only work on one substrate

15. What does it mean for an enzyme to become “denatured?”How might this happen?

• It changes shape and can no longer bind to its substrate. Therefore, it can’t break it down.

• A change in temperature or pH.

16. What factors affect enzyme action?How does each affect enzyme action?

• Temperature• pH

• Enzymes operate most efficiently within a certain temperature and pH range.

CELLS AND ENERGY

Unit 2

17. Examine the graphic below, is it a plant or animal cell?

• Animal Cell• No cell wall• No chloroplasts• No central vacuole

18. Label the organelles below and identify the function of each.

A. Ribosome – site of protein synthesis

B. Mitochondria – Produces ATP

A. Nucleus – Contains the DNA

A.  Centriole – Produces spindle fibers.(formed from microtubles)

B. Cell membrane – Regulates whatenters/exits the cell.

19. Explain several differences between plant and animal cells.Explain several similarities.

20. Explain diffusion, osmosis, active transport, and passive transport. List some similarities and differences.

• Passive Transport – Requires no energy from the cell. Takes advantage of the natural movement of particles (follows the concentration gradient).

• Diffusion – Movement of molecules from an area of high concentration to an area of low concentration until equilibrium is reached.

• Osmosis – Diffusion of water.

• Active Transport – Requires energy from the cell. Moves material against the concentration gradient (from low to high).

Passive Transport

Active Transport

21. Create sketches to explain what happens to a cell when it is

in a hypotonic solution, a hypertonic solution, and an isotonic solution.

22. Determine total magnification by completing the table below:

Total Magnification = Objective Lens x Eye Piece

23. Which one will have the most organisms in the field of view?Which one has the least?

• Most – 80x Magnification. It is not zoomed in as much, so the field of view is much larger

• Least – 200x Magnification. It is zoomed in much more, so it has a smaller field of view. You will see fewer organisms, but in greater detail.

24. Label the parts of a microscope and give their functions.

Eyepiece

Body tube

Revolvingnosepiece

Objective lens

Stage

Diaphragm

Light source

Coarse focus

Fine focus

Power switch

25. What is the difference between prokaryotic and eukaryotic cells?

Give an example of each.

• Prokaryotic – Does not contain a nucleus• Ex) Bacterium

• Eukaryotic – Contains a nucleus and membrane bound organelles• Plant or animal cell

26. Write the general equation of photosynthesis.

• 6CO2 + 6H2O C6H12O6 + 6O2

• Carbon dioxide + Water Glucose + Oxygen

27. What is the purpose of photosynthesis?

Plants convert the light energy from sunlight into chemical energy in the form of Glucose (sugar)

In this process, they release the oxygen we need to breathe.

28. What effect do increases in temperature, CO2 or light have on the rate of photosynthesis?

• Temperature – Rate of photosynthesis will increase and then decrease.

• CO2 and Light Intensity – Rate of photosynthesis will increase and then level off.

29. Write out the equation for cellular respiration.

• 6O2 + C6H12O6 6H2O +6CO2 + 36 ATP

• Oxygen + Glucose Carbon dioxide + Water + ATP

30. What is the purpose of cellular respiration?

• The process by which cells produce energy (ATP) from carbohydrates.

31. Where do respiration and photosynthesis occur in a cell?

Respiration – Mitochondria in animal AND PLANT CELLS

Photosynthesis – Chloroplasts in plant cells

32.Why is ATP so important to living things?

ATP provides cells the energy they need to carry out ALL activities Cell division Growth Repair And many, many more . . . Everything!

33. Compare and contrast respiration and photosynthesis.

EVOLUTION AND CLASSIFICATION

Unit 3

34. Explain the parts of Darwin's theory of Evolution by natural selection.

1) The members of a population have heritable variations.• size, coloration, strength, behavior

2) In each population, many more individuals are produced each generation than the environment can support.

3) Some individuals possess adaptations that enable them to survive and reproduce more than other individuals.

4) An increasing number of individuals in succeeding generations possess the adaptation.

5) The result of natural selection is a population adapted to its local environment.

34. Explain the parts of Darwin's theory of Evolution by natural selection.

Natural Selection Stated Simply . . .

1) Variation within a population

2) Struggle for existence3) Survival of the fittest4) Descent with modification5) Change over time

35. Explain in detail how Darwin would explain the evolution of

giraffes from a population of ancestors that had short necks.

• Within a population of giraffes, some have a longer neck than others (variation).

• Giraffes are always competing for food (struggle for existence).

• Those giraffes with a longer neck will be able to reach more food (survival of the fittest).

• They will survive to reproduce and pass the beneficial trait on to their offspring (descent with modification).

• Over time, the population of giraffes will have more members with longer necks (change over time).

36. Explain Lamarck's theory of evolution.Include use/disuse and acquired characteristics.

• The more an organism uses a structure, the more developed it will become. For example, a giraffe will continually stretch its neck to reach the leaves in the upper canopy of the trees. Over its lifetime, the giraffe will ACQUIRE a longer neck. The giraffe can pass this acquired trait onto its offspring. We now know this is not correct! ACQUIRED TRAITS ARE NOT INHERITED!

37. Describe 5 evidences that support evolution.

1. fossils – Paleontologists can compare fossils from the past to organisms living today.

2. homologous structures – Organisms have very similar structures that have been modified for different functions.

3. vestigial structures – A remnant (left over) structure that no longer serves a purpose but was useful in an ancestral stage.

4. embryology – Organisms that are very different (i.e. a fish and a human) still have very similar stages of embryonic (pre–birth) stages of development.

5. DNA – The more recently two species share a common ancestor, the more similar their DNA will be. Organisms that do not share a recent common ancestor, will have a greater % difference in their DNA

38. Explain the 3 types of selection (directional, disruptive, and stabilizing).

• Stabilizing – The norm is selected for and the extremes are selected against.

• Directional – One extreme is selected for.• Disruptive – The norm is selected against and the extremes are selected

for

39. What is Binomial Nomenclature? What are the rules for writing a scientific name? Give an example.

• Two word naming system• Genus name is first, capitalized• Species name is second, not capitalized• Entire name is either underlined OR italicized• Ex) Homo sapiens

40. Who created the modern system for classification?

• Carolus Linnaeus is considered the “Father of Taxonomy”

41. List the taxonomic categories in order from most general to specific. Which organisms are most closely related? Which are

least closely related?

• Domain Kingdom Phylum Class Order Family Genus Species

• Does King Phillip chew on fat green stems?

• As you move toward the species taxon, organisms are more closely related.

• Ex) In the Animal Kingdom you have organisms that are very different; sponge and Chimpanzee

• In the Class Mammalia, organisms are more similar to one another since they are all mammals.

42. List the characteristics of each of the 6 kingdoms and give an example of two organisms in each kingdom.

43. What determines whether 2 organisms are members of the same species?

Only members of the same species can breed and produce FERTILE offspring.

44. How are fossils used by scientists to support the theory of natural selection?

• Fossil – The trace (ex: footprints) or remains of an organism that lived long ago, preserved in Sedimentary rock.

• Paleontologists can examine the fossil record and observe how species have changed over time.

GENETICS I – DNA, RNA,AND PROTEIN SYNTHESIS

Unit 4

45. Who were Hershey and Chase?Explain their experiment and what it proved.

• Worked with bacteriophages (viruses), which are made of only DNA and protein

• Alternated between using radioactive DNA or radioactive protein• Sulfur isotope (35S) – only found in protein coat• Phosphorous isotope (32P) – only found in DNA

• Looked to see if bacteria became radioactive when radioactive DNA or when radioactive protein was inserted by the virus

• The bacteria only became radioactive when radioactive DNA was used

• Conclusion – DNA is what is inserted into the bacteria, not the protein!

• Hershey Chase Video Clip

The Hershey and Chase Experiment

46. Who was Griffith? Explain his experiments and what he proved.

• Examined Streptococcus pneumoniae strains and mice• S strain of bacteria cause pneumonia• R strain of bacteria does NOT cause pneumonia• S strain of bacteria can be killed and rendered harmless by

heating• R bacteria mixed with heat-killed S bacteria can still cause

infection• Conclusion – Some type of material can move from the heat–

killed S bacteria to the R bacteria to cause disease, and that this must be the genetic material—TRANSFORMATION

• Transformation – change in the genotype (genetic makeup of an organism) caused when cells take up foreign genetic material

• The cause of transformation was not known at the time• Griffith's Experiment Video Clip

Griffith’s Experiment – 1928

47. Who are Watson and Crick? What did they do for the field of biology?

• The structure of DNA was discovered in 1953 by James Watson and Francis Crick.

• They received the Nobel prize.

48. Draw a diagram of a DNA molecule containing 4 base pairs. Label the following: deoxyribose, phosphate, adenine, guanine, cytosine, thymine, nucleotide, hydrogen bonds covalent bonds.

Covalent bonds

49. What is a nucleotide?What is a nucleotide made up of (be specific)?

• Nucleotide – Building bock of a nucleic acid (DNA or RNA)

• Made up of a sugar, phosphate, and nitrogen base

50. What is DNA replication? Explain the process of DNA replication? What enzymes are involved in this process?

• DNA Replication – When DNA makes a copy of itself.• The two strands of DNA are separated by enzymes called

helicases that break hydrogen bonds as they move along the strand.

• Enzymes called DNA polymerases bind to the chains and assemble new strands of DNA by attaching a new nucleotide to the complementary strand.

• The end result is two pieces of DNA that are each half new and half old DNA.

• Errors are repaired by other enzymes that “proofread” the new DNA.

DNA Replication

51. Why is replication of DNA important to organisms?

• The cell must replicate (copy) the DNA in order to have two sets for each new daughter cell after mitosis.

52. What happens during transcription? Explain the process.

• Transcription – Process of copying DNA into RNA. This is the first phase of protein synthesis which takes place in the nucleus.

53. What occurs during translation?Explain the process.

Translation – The second part of protein synthesis takes place at the ribosome. The mRNA that was made in transcription travels out of the nucleus and to a ribosome on the ER or in the cytoplasm.

Amino acids that are freely floating in the cytoplasm are transported to the ribosome by the tRNAs. Part of the tRNA contains a region of three bases called the anticodon. Only the anticodon that matches the mRNA codon will be able to donate an amino acid so that the DNA’s message is translated into a protein correctly.

Translation

54. How many bases are needed to code for 1 amino acid?What is this called on mRNA?

• 3 bases code for 1 amino acid

• Called a codon

RNARNA DNADNA

Contains the nitrogen base Uracil

Sugar is Ribose

Single stand

Can leave nucleus

Contains the nitrogen base Thymine

Sugar is Deoxyribose

Double strand

Can’t leave nucleus

55. What are 3 differences between RNA and DNA?

56. What are 3 differences between mRNA, rRNA and tRNA?

• Messenger RNA (mRNA) – Made by copying the DNA, takes the message to the ribosome to make proteins allowing the DNA to safely stay in the nucleus.

• Transfer RNA (tRNA) – Carries the correct amino acid to the ribosome from the cytoplasm to add it to the protein, very specific.

• Ribosomal RNA (rRNA) – Makes up the ribosome.

57. Transcribe this DNA to mRNA, then to tRNA,then determine its amino acid sequence:

• DNA T A C | G C T | A C C | A T C | A G T

• mRNA A U G | C G A | U G G | U A G | U C A

• tRNA U A C | G C U | A C C | A U C | A G U

• Amino acid sequence start, arginine, tryptophan, stop, (serine)

58. What are the three types of point mutations? Which ones will cause the most harm? Which might have no effect at all?

• Addition – One or more bases are added to the strand.

• Deletion – One or more bases are omitted from the strand.

• Substitution – One base is put in the strand in place of another

• Most harm – Addition & deletions since they will cause a frameshift.

• No effect – When the same amino acid is inserted.• UCU, UCC, UCA, and UCG all code for serine

Types of Mutations

59. What is cancer? What are some causes of cancer? Treatments of cancer? Ways to prevent cancer?

• Cancer – Cells divide at an uncontrolled rate. Essentially, it is a disorder of cell division.• Oncogenes become more active speeding up cell division• Tumor suppressor genes (prevent cell division from occurring

too often) are damaged

• Causes – Environmental factors (pollution, pesticides, radiation)

• Treatments – Anticancer drugs, chemotherapy, radiation, surgery.

• Prevention – Don’t smoke, proper diet, exercise, have regular medical exams for early detection.

60. What is a mutagen? Carcinogen?

• Mutagen – Cause damage to DNA leading to mutation. Ex) radiation

• Carcinogen – Anything that causes cancer.

61. What types of cells are diploid? What types of cells are haploid ?

• Diploid – Somatic cells (body cells)

• Haploid – Gametes (sperm and eggs)

62. What is a somatic cell?

• Somatic cells – ANY body cells that are NOT sperm or egg

63. Answer the following questions and assume you are using a human cell with 46 chromosomes:

a) What is the diploid number? 46

a) What is the haploid number? 23

b) If this cell went through mitosis, how many chromosomes would the daughter cells have? 46

c) If a cell went through meiosis how many chromosomes would the daughter cells have? 23

64. What is genetics?

• Genetics – The science of heredity and of the mechanisms by which traits are passed from parent to offspring.

65. Diagram out a cell going through mitosis as well as a cell going through meiosis. Assume you start with a cell with 6

chromosomes.Be sure to note what is going on and any

similarities/differences.

XXXXXX

XXXXXX

XXXXXX

XXXXXX

XXXXXX

XXXXXX

XXX XXX XXX XXX

MITOSISMITOSIS MEIOSISMEIOSIS

• A type of cell division

• Produces somatic cells (body)

• Results in two daughter cells

•  Daughter cells are geneticallyidentical to parent cell

• Daughter cells are diploid

• A type of cell division

• Produces gametes (sperm & ova)

• Results in four daughter cells

• Daughter cells are geneticallydifferent to parent cell

• Daughter cells are haploid

Mitosis vs. Meiosis

66. What are the major functions of mitosis?What are the major functions of meiosis?

• Mitosis – A type of cell division that produces somatic cells.

• Meiosis – A type of cell division that results in gametes.• Only occurs in gonads (sex organs)

• Male – testes• Female – ovaries

• Produces haploid cells• Haploid – half set of chromosomes• Diploid – full set of chromosomes

• The process of meiosis maintains the chromosome number.Egg + sperm = zygote

23 + 23 = 46

67. Who was Gregor Mendel?What did he do?

• Gregor Mendel was an Austrian monk who studied the inheritance patterns in pea plants. His knowledge of statistics allowed him to make very accurate studies of seven traits in peas and how they were passed from one generation to the next.

• He began the study of genetics and is considered the Father of Genetics.

68. What are alleles?

• Alleles – Form of a trait, Aa• Can either be dominant or recessive

69. Concept generalization:

• Dominant – Expressed• Recessive – Masked by dominant allele• Homozygous – Two of the same alleles, AA or aa• Heterozygous – Two different alleles, Aa• Genotype – What alleles a person has, AA, Aa, or aa• Phenotype – Physical appearance based on genotype, brown

eyes• Allele – Form of a trait, dominant (A) or recessive (a)• Test cross – See question # 71• Genotypic ratio – Predicted genotypes in F1 generation• Phenotypic ratio – Predicted phenotypes in F1 generation

70. List and explain Mendel’s three laws.

• Law of Dominance – When two different alleles occur together (in a heterozygous individual; Aa) one of them may be completely expressed, while the other may have no observable effect on the organism’s appearance.

• Law of Segregation – Two alleles for a trait segregate (separate) during meiosis when gametes are formed.

• Law of Independent Assortment – The inheritance of one trait does NOT influence the inheritance of another trait.

71. What is a test cross?Why is it used?

• Test cross – Used to determine the genotype of an individual with a dominant phenotype in order to determine if they are Heterozygous or Homozygous dominant. You will cross them with a homozygous recessive individual. If offspring are produced with the recessive phenotype, the individual must be Heterozygous.

72. Two pink 4 o’clock flowers are crossed.What will be the genotypes and phenotypes of their offspring?

 

• What is the genotypic ratio?• 1RR : 2Rr : 1rr

• What is the phenotypic ratio?• 1 Red : 2 pink : 1 white

R

RR

Rr

Rr

rr

R

r

r

73. A man with colorblindness marries a woman whose mom was colorblind and dad was normal.

• What are the chances that their kids will be colorblind?• 50 %

Xb

XBXb

XbXb

XBY

XbY

XB

Xb

Y

74. Solve these multiple allele problems.Show genotypes and phenotypes of the offspring.

A. Blood types AB x OO

A

AO

AO

BO

BO

O

O

B

74. Solve these multiple allele problems.Show genotypes and phenotypes of the offspring.

B. Could a man with A blood and a woman with B blood have a child with O blood? YES! A

AB

AO

BO

OO

B

O

O

75. Flower color is incompletely dominant in four-o-clocks. How could offspring that are only pink be obtained? Be sure

to show all work!

• Cross a red flower (RR) with a white one (rr). ALL the offspring will be pink (Rr)

R

Rr

Rr

Rr

Rr

r

r

R

76. What is the difference between autosomes and sex chromosomes?

Autosomes – Not involved in determining the sex of an individual. Chromosomes 1 – 22

Sex Chromosomes – 23 pair. Contain genes that will determine the sex of the individual.

77. What determines the sex of a human?

• The Sex Chromosomes they inherit.• Females – XX• Males – XY

78. A color-blind man whose mother was homozygous for dark skin and father was light skinned marries a woman whose

father was color blind and light skinned and mother was also light skinned.

• What are the possible genotypes and phenotypes for their offspring? Assume that dark skin is dominant to light skin.

• This is a dihybrid Cross with one of the traits being sex–Linked!

• First draw a pedigree to figure out the genotypes of the individuals.

dd BX dd bY

dd Bb Dd bY

DD Bb dd BY

78. A color-blind man whose mother was homozygous for dark skin and father was light skinned marries a woman whose

father was color blind and light skinned and mother was also light skinned.

• What are the possible genotypes and phenotypes for their offspring? Assume that dark skin is dominant to light skin.

• This is a dihybrid Cross with one of the traits being sex–Linked!

• Then FOIL to figure out possible allele combinations in parent gametes

dXB

DdXBXb

DdXBY

DdXbXb

DdXbY

DXb

DY

dXb

ddXBXb ddXbXbdXb

ddXBY ddXbYdY

# 79

• A man who is heterozygous for being tall and has attached earlobes marries a woman who is short and heterozygous for unattached earlobes. List out the gametes for both parents and the genotypic and phenotypic ratios.

• Key• T= tall• t = short• E = Unattached earlobes• e = attached earlobes

• Man = Ttee • Woman = ttEe

# 79 Continued

• A man who is heterozygous for being tall and has attached earlobes marries a woman who is short and heterozygous for unattached earlobes. List out the gametes for both parents and the genotypic and phenotypic ratios.

• FOIL to find the combination of alleles that can occur in the gametes• Man = Ttee = Te, Te, te, te, or Te and te

• Woman = ttEe = tE, te, tE, te, or tE and te

• Now, do the cross . . .

# 79 Continued

• A man who is heterozygous for being tall and has attached earlobes marries a woman who is short and heterozygous for unattached earlobes. List out the gametes for both parents and the genotypic and phenotypic ratios.• T= tall• T = short• E = Unattached earlobes• e = attached earlobes

• Genotypic ration – 1 TtEe : 1 ttEe : 1Ttee : 1ttee• Phenotypic ratio – 1 Tall w/ unattached : 1 short w/

unattached : tall w/attached : 1 short w/ attached

Te

TtEe

Ttee

ttEe

ttee

tE

te

te

80. What is nondisjunction? When does it occur?Provide 3 examples of nondisjunction disorders.

Nondisjunction – When the chromosomes do not separate properly during meiosis.

A gamete (sperm, egg) ends up with an extra or missing chromosomes as a result

Ex) Downs Syndrome – Trisomy 21

Klinefelter’s Syndrome – XXY or XXXY. Males receive an extra X chromosome.

Turners Syndrome – X0; Sterile female who is missing or has an incomplete X chromosome

81. What is a karyotype?How is it used by biologists?

Picture of a person’s chromosomes

To see if the have a monosomy (missing a chromosome) or a trisomy (extra copy of a chromosome)

81. Draw a Pedigree for the following family.

A straight thumb is recessive to a curved (hitchiker's) thumb. Bob and Linda are a married couple. Bob has a hitchhikers thumb like his father, but his mother did not. Linda has a straight thumb as do both of her parents. Bob and Linda have three children: A boy with hitchikers thumb, a boy with a straight thumb, and a girl with a straight thumb.

T_ T_

Linda, Tt Bob, Tt

ttT_tt

tt T_