Sexual Reproduction,

MeiosisHomework

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CP Biology 2012-13 Name _______________________

Record of Incomplete Homework for this Unit:

Record the following information for every assignment not completed on time.Use the choices below the table.

Homework # Date Assigned I did not complete this HW because:

A. I did not record it in my planner/ I did not check the class websiteB. I did not understand the material and have arranged to see the teacher for helpC. I did not understand the material and did not see the teacher for helpD. I forgot/ I just didn’t do itE. OTHER: Please explain any extraordinary circumstances

HW #1: Haploid and Diploid Numbers of Chromosomes

Use the table to answer the following questions.

1) Fill in the number of chromosomes in the chart below.

2) What is the diploid (2n) number for humans? ______46_________

3) What is the haploid (n) number for humans? _______23________

4) Does a human brain cell contain the haploid (n) or diploid (2n) number of chromosomes?_______________

5) Does a human sperm cell contain the haploid (n) or diploid (2n) number of chromosomes? ______________

6) What is the diploid (2n) number for a housefly? ____12__________

7) What is the haploid (n) number for a chicken? _____39______

8) How many chromosomes are in the blood cells of a goldfish? __94__

Is this the n or 2n number?_____

9) How many chromosomes are in the sperm cells of a horse? __32_____

Is this the n or 2n number? _____

10) The cells below are from a fruit fly. The shapes inside the cells are single arm chromosomes. Label each cell as being a haploid or diploid cell:

a. _haploid____ b. ___diploid_____

HW #2: Homologous Pairs of Chromosomes

Organism Number of Chromosomes in each body cell.

Number of Chromosomes in

each sex cell.

goldfish 94 47

chicken 78 39

horse 64 32

sand dollar 52 26

chimpanzee 48 24

dog 48 24

human 46 23

brown bat 44 22

corn plant 20 10

housefly 12 6

fruit fly 8 4

The following drawing is a homologous pair of replicated chromosomes. Use the letters above each chromatid to answer the following questions.

A B C D ______ 1) Which of the following is the sister chromatid of C? a. A b. B c. D

______ 2) If C-D is a maternal homolog, what is A-B?

a. maternal also b. paternal c. cannot determine

______ 3) Chromatids B and D have the same nucleotide sequence.

a. true b. false c. possible, not always

______ 4) Chromatids A and B have the same nucleotide sequence.

a. true b. false c. possible, not always

______ 5) A gene that codes for the shape of your hairline is found on B. Which of the following will also contain a gene which codes for the shape of your

hairline?

a. A b. B c. C d. D e. All of these ______ 6) If B has a gene that contains the sequence for a pointed (widow’s peak)

hairline, which of the following will ALWAYS have the exact same nucleotide sequence?

a. A b. Only B c. C d. D e. All of these

HW #3: Drawing the Stages of Meiosis

Given the information in each question, draw an animal cell that represents the stage of cell division. You only need to draw the chromosomes, spindle fibers, nuclear membrane and furrow if present.:

MEIOSIS I: MEIOSIS II:

1) The diploid number is 4. Draw a cell in prophase I.

5) The diploid number is 4, draw a cell in prophase II.

2) The haploid number is 2. Draw a cell in metaphase I.

6) The haploid number is 2. Draw a cell in metaphase II.

3) The diploid number is 4. Draw a cell in anaphase I.

7) The diploid number is 4. Draw a cell in anaphase II.

4) The haploid number is 2. Draw a cell in telophase I.

8) The haploid number is 2. Draw a cell in telophase II.

9) Could the above pictures represent cells from the same species of organism? Explain. __YES. The chromosome number is the same for all of them!!!_ _

Homologous chromosomes find each other. (synapsis) and (crossing

Homologous chromosomes line up on equator in pairs.

Homologous chromosomes move to opposite poles.

Nuclear membrane reforms around haploid cells. (really completes at cytokinesis.) Furrow or

Should be 2 separate cells in for this ENTIRE side of the page.(#5,6,7)

Sister chromatids now separate at the centromere and move to opposite poles.

THIS SHOULD SHOW 4 CELLS - HAPLOID SINGLE ARMED (each circle should have 2 chromosomes)

10) The diploid number is 6. Draw a cell in metaphase of MITOSIS.

11) The diploid number is 6. Draw a cell in metaphase I of MEIOSIS.

HW #4 COMPARISON OF MEIOSIS AND MITOSIS

MEIOSIS MITOSIS

Kinds of cells produced (somatic vs. sex cells?

haploid or diploid cells?)

SEXHAPLOID

SOMATICDIPLOID

Number of cells produced per beginning cell

4 2

Chromosome number in parent cell (haploid or diploid)

46 = diploid (2n) 46 = diploid (2n)

Chromosome number in daughter cells (haploid or

diploid) 23 = haploid (n) 46 = diploid (2n)

Number of times the DNA is replicated

1 1

Number of cell divisions 2 1

Function To form gametes for

sexual reproduction.

1) To form new cells duringgrowth or to repair damaged

cells.

2) To produce a new organismduring asexual reproduction.

HW #5: Meiosis I vs. Meiosis II

Select the correct stage of nuclear division for the statements below:

a. meiosis I b. meiosis II

_A____1) A diploid number of chromosomes is reduced to a haploid number.

_B____2) Double arm chromosomes are split to produce haploid cells with single arm chromosomes.

_A____3) Synapsis is taking place as double arm homologs orient close to each other.

_B____4) A haploid number of double arm chromosomes lies in the middle of the cell.

_A____5) Spindle fibers separate homologous pairs of double arm chromosomes.

_B____6) Cell contains only one of each type of chromosome (one #1, one #2, one #3, and so on).

_A____7) Telophase takes place as the nuclear membrane surrounds double arm chromosomes.

_B____8) A haploid number of single arm chromosomes lies at the poles of a cell.

Extension: If the 2n number of chromosomes in an organism is 8. Which of the following cells is in prophase II of meiosis? (Circle one)

A. B. C.

HW #6 Meiosis ReviewChromosome NumberFor Questions 1–8, write True if the statement is true. If the statement is false, change the underlined word to make the statement true.

TRUE 1. The offspring of two parents obtains a single copy of every gene from each parent.

TRUE 2. A gamete must contain one complete set of genes.

CHROMOSOMES 3. Genes are located at specific positions on spindles.

HOMOLOGOUS 4. A pair of corresponding chromosomes is homozygous.

PARENT 5. One member of each homologous chromosome pair comes from each gene.

DIPLOID 6. A cell that contains both sets of homologous chromosomes is haploid.

TRUE 7. The gametes of sexually reproducing organisms are haploid.

12 ______________ 8. If an organism’s haploid number is 6, its diploid number is 3.

Phases of MeiosisOn the lines provided, identify the stage of meiosis I or meiosis II in which the event described occurs.

PROPHASE I 9. Each replicated chromosome pairs with its corresponding homologous chromosome.

PROPHASE I 10. Crossing-over occurs between tetrads.

METAPHASE I 11. Paired homologous chromosomes line up across the center of the cell.

ANAPHASE I 12. Spindle fibers pull each homologous chromosome pair toward an opposite end of the cell.

TELOPHASE I 13. A nuclear membrane forms around each cluster of chromosomes and cytokinesis follows, forming two new cells.

PROPHASE II 14. Chromosomes consist of two chromatids, but they do not pair to form tetrads.

TELOPHASE I I 15. A nuclear membrane forms around each cluster of chromosomes and cytokinesis follows, forming four new cells.

16. THINK VISUALLY: Draw two homologous pairs of chromosomes (in different colors if you have them) in these diagrams to illustrate what happens during these three phases of meiosis.

17. Identify which phase of meiosis is shown in the diagrams below.

Use the diagram at the right to answer Questions 18–20.

18. What does the diagram show?It shows crossing-over of genes between a pair

INTERPHASE I

TELOPHASE II AND CYTOKINESIS

of homologous chromosomes.

19. During what phase of meiosis does this process occur?It occurs during prophase I of meiosis.

20. What is the result of this process?The result is a new combination of alleles.

Comparing Meiosis and Mitosis21. Complete the table to compare meiosis and mitosis.

Mitosis MeiosisForm of reproduction

Asexual First stage in sexual

Number of daughter cells

2 4

Change in chromosome number

No change; stays diploid Cut in half to diploid

Number of cell divisions

1 2

Difference in alleles between parent cell and daughter cells

None

Each of the four daughter cells is genetically different from the parent.

For Questions 22–27, use the word bank to complete each statement by writing the correct word or words.

22. A diploid cell that enters mitosis with 16 chromosomes will divide to produce ___ 2_ ____ daughter cells. Each of these daughter cells will have 16 chromosomes.

23. If the diploid number of chromosomes for an organism is 16, each daughter cell after mitosis will contain 16 chromosomes.

24. A diploid cell that enters meiosis with 16 chromosomes will pass through 2 cell divisions, producing 4 daughter cells, each with 8 chromosomes.

25. Gametes have a haploid number of chromosomes.

26. If an organism’s haploid number is 5, its diploid number is 10 .

27. While a haploid number of chromosomes may be even or odd, a diploid number is always even.

one two four eight sixteen thirty-two haploid diploid even odd