Download Problem Set 2

Problem set 2, Spring 2017
student name:
8 points total
1. Diagram anaphase of mitosis for a diploid organism that contains 2 pairs chromosomes – 1
long and 1 short.
2. Diagram metaphase of mitosis for a haploid organism that contains 2 chromosomes.
3. Mitosis resembles the second meiotic division. How are they similar? How do they differ?
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Problem set 2, Spring 2017
8 points total
student name:
4. In studying a eukaryotic organism D. webbae, recently discovered on an asteroid floating in
space, you find that it has a rather unusual meiosis. In D. webbae, cells destined to undergo
meiosis skip S-phase, and then undergo only the first meiotic division. Draw out prophase,
metaphase, and anaphase of meiosis, and the daughter cells produced by D. webbae showing
the chromosomes. Assume D. webbae is diploid with three pairs of homologous chromosomes.
What are the consequences of this unusual type of meiosis?
5.
A. This diploid cell goes through a normal mitotic cell
cycle. Show metaphase of mitosis and the daughters
produced, including genes and chromosomes.
c
A
B
C
a
B
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Problem set 2, Spring 2017
student name:
8 points total
B. Show chromosomes and spindle of this cell in anaphase II of meiosis. (You don’t need to
include the genes.)
6. A. schlenzae is a newly discovered red-spotted poison dart frog from Costa Rica.
Chromosome analysis of A. schlenzae indicates that the species is diploid with two pairs of
chromosomes, one long and one short. Simple genetic analysis indicates that the gene (R) that
specifies the red spots is located on the long chromosome, and a gene (L) that specifies body
length resides on the short chromosome.
A. Show the products at the beginning of G1 phase of a single mitosis of a A. schlenzae
cell. Assume the parent cell is heterozygous (i.e. R on one homolog and r on the second,
L on one homolog andl on the second) for both genes. How many chromosomes are
present in each cell? How many chromatids are present in each cell?
B. Diagram the appearance of the chromosomes at metaphase of meiosis I. Draw a circle
around the homologous chromosomes and a box around the sister chromatids. Assume
the parent cell is heterozygous for both genes.
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Problem set 2, Spring 2017
8 points total
student name:
7. Do the following occur in meiosis I, meiosis II or mitosis? (Each blank may contain more
than one answer.
a. At least one crossover per homologous pair can occur
b. chromosomes line up singly along the metaphase plate
c. ploidy level is decreased by half
d. DNA synthesis takes place prior to division
e. Produces somatic cells
f. Homologous chromosomes separate from each other
8. The cells shown in A through D all came from the same individual. In the spaces below each
cell, identify the type of division (mitosis or meiosis) taking place and the stage of that division
represented in the cell (anaphase, prophase I, etc.).
a.
b.
Division:
Stage:
Division:
Stage:
c.
d.
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Problem set 2, Spring 2017
8 points total
student name:
Division:
Stage:
Division:
Stage:
The following questions refer to the figures shown above in a – d.
How many chromosomes in cell in d?
How many chromatids?
In which cell(s) are homologues separating?
In which cell(s) are sister chromatids separating from each other?
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