Biol 1107 Exam 3 Study Guide
Table of Contents
1. Practice Exam 3. Top Hat Questions
2. Quizelt Review
Practice Exam
Key
My Answer
Correct Teacher Answer
1. Indicate the amount of DNA, number of chromosomes, and number of chromatids inside a
cell before or during mitotic division if there are 2 pg of DNA and 6 chromosomes
Phase DNA (picogram) Chromsoomes Chromatids
G1260
S4 6 12
G24 6 12
Prophase 4 6 12
Prometaphse 4 6 12
Metaphase 4 6 12
Anaphase 4 12 0
Telophase 4 12 0
G1260
Phase DNA (picogram) Chromsoomes Chromatids
G1260
S4 6 12
G24 6 12
Prophase 4 6 12
Prometaphse 4 6 12
Metaphase 4 6 12
Anaphase 4 12 0
Telophase 4 12 0
G1260
,2. How many copied of a gene on an autosome in a human cell at the start of mitosis? Explain
At the beginning of mitosis there would be copies because human autosome
cells are diploid meaning they have 2 copies of each gene. We also know that they
have 2 copies because the only cells in the human body with less than 2 copies are
gametes and they are haploid
4 (2 during G1 phase on the paired autosomes → 4 after replication during the S
phase). It has to double at the beginning of mitosis so that the ploidy does not change at the end of
mitosis and is able to remain the same
3. Indicate the amount of DNA, number of chromosomes, and number of chromatids inside a
cell before or duing meiotic division if there are 4 pg of DNA and 8 chromosomes in the G1
phase
Phase DNA (picograms) Chromosomes Chomatids
G1480
S8 8 16
G28 8 16
End of Meiosis I 448
End of Meisosis II 240
Phase DNA (picograms) Chromosomes Chomatids
G1480
S8 8 16
G28 8 16
End of Meiosis I 448
End of Meisosis II 240
4. A diploid plat is used to produce a tetraploid (4n) variety. If somatic cells from the tetraploid
variety have 72 chromosomes, how many chromosomes are in a gamete for the diploid
plant?
72/4 = 18 chromosomes in a gamete from the diploid plant. If the question
gives you the number of chromsoomes in the somatic cell divide by the ploidy number but if
it give you the number of chromosomes in the gamete then multiply by the ploidy number
Gametes from diploid plants are haploid (n), and if 4n=72, then one set (n) is 18
chromosomes
5. Assuming no recombination during meiosis, how many different gametes can a diploid
animal produce based solely on independent assortment if each gamete contains 12
chromsosomes?
======
======
2 2 2 2 2 2 = 26 = 64 different gametes
Gametes are n=12, somatic cells are 2n=24. And there would be 212 or 4,096
different gametes
, 6. Zorses are the rare offspring of male zebras (2n=44) and female horses 2n=64). Assuming
no recombination during meiosis, how many genetically distcinct zorses can 2 parents
produce?
22 chromosomes in zebra gamete, 32 chromosomes in horse gamete
222 x 232 = 1.80 x 1016 different gametes
When looking for the number of different possible products take each parent and
find their distinct possibilities than multiply those 2 number together to find the total
possibilities
A male zebra can produce 222 different sperm and female horses can produce 232
differnt eggs based on independent assortment, so 2 parents could have 222 x 232 = 1.80 x
1016 unique zorses
7. Use your knowledge of meiotic division to explain why the zorses described above are
infertile?
The zorses would be infertile because there would be an unequal pairing of
chromosomes within the cell because the mother and father contriubyet different
numbers of chromosomes to the resulting cell. This would leave some of the
chromosome unpaired so when the cell divides during meiosis one of the daughter
cell would have more chromosomes than the other
Zorses have n=22 chromosomes from the zebra and n=32 from the horse, so the
chromosome cannot pair correctly and be divided evenly during mieotic division to produce
viable gametes
8. Half of your DNA came from your biological mother (egg), and half came from your
biological father (sperm), but did a quarter of your DNA ceom from each biological
grandparent?
Yes I think that ¼ of your DNA would come from your biological
grandparents because you are half of your mother and father and your mother and
father are half of their their mother and father. So that would make you are ¼ of your
biological grandparents. This also makes sense when you think about generations
because you have to in some what be related genetically to your grandparents
Due to independent assortment and recombination during meiosis in your parents, it
is unlikely that a quarter of your DNA came from you grandparents. These events of meiosis
are random so genetic testing is needed to determine grandparent contribution (varies from
15% to 35%)
9. Cavendish bananas at grocery stores came from triploid (3n) plants that are unable to
reproduce sexually. Use your knowledge of mitotic and meiotic division to explain why the
plants can be propagated asexually (by growing new plants from the stem of a parent plant)
but not sexually
The plants can be propagated asexually because the ploidy for asexual
reproduction does not matter. It would just proceed normally and produce an
exponential amount of daughter cells. The plant cannot reproduce sexually because
of the odd ploidy that is present. Because of the uneven ploidy nondisjunction will
always occur if you try to sexually reproduce
Banana plants can be propagated asexually through mitotic division, since
mitosis will produce identical muceli and does not change ploidy (3n → 3n). Meiotic
Table of Contents
1. Practice Exam 3. Top Hat Questions
2. Quizelt Review
Practice Exam
Key
My Answer
Correct Teacher Answer
1. Indicate the amount of DNA, number of chromosomes, and number of chromatids inside a
cell before or during mitotic division if there are 2 pg of DNA and 6 chromosomes
Phase DNA (picogram) Chromsoomes Chromatids
G1260
S4 6 12
G24 6 12
Prophase 4 6 12
Prometaphse 4 6 12
Metaphase 4 6 12
Anaphase 4 12 0
Telophase 4 12 0
G1260
Phase DNA (picogram) Chromsoomes Chromatids
G1260
S4 6 12
G24 6 12
Prophase 4 6 12
Prometaphse 4 6 12
Metaphase 4 6 12
Anaphase 4 12 0
Telophase 4 12 0
G1260
,2. How many copied of a gene on an autosome in a human cell at the start of mitosis? Explain
At the beginning of mitosis there would be copies because human autosome
cells are diploid meaning they have 2 copies of each gene. We also know that they
have 2 copies because the only cells in the human body with less than 2 copies are
gametes and they are haploid
4 (2 during G1 phase on the paired autosomes → 4 after replication during the S
phase). It has to double at the beginning of mitosis so that the ploidy does not change at the end of
mitosis and is able to remain the same
3. Indicate the amount of DNA, number of chromosomes, and number of chromatids inside a
cell before or duing meiotic division if there are 4 pg of DNA and 8 chromosomes in the G1
phase
Phase DNA (picograms) Chromosomes Chomatids
G1480
S8 8 16
G28 8 16
End of Meiosis I 448
End of Meisosis II 240
Phase DNA (picograms) Chromosomes Chomatids
G1480
S8 8 16
G28 8 16
End of Meiosis I 448
End of Meisosis II 240
4. A diploid plat is used to produce a tetraploid (4n) variety. If somatic cells from the tetraploid
variety have 72 chromosomes, how many chromosomes are in a gamete for the diploid
plant?
72/4 = 18 chromosomes in a gamete from the diploid plant. If the question
gives you the number of chromsoomes in the somatic cell divide by the ploidy number but if
it give you the number of chromosomes in the gamete then multiply by the ploidy number
Gametes from diploid plants are haploid (n), and if 4n=72, then one set (n) is 18
chromosomes
5. Assuming no recombination during meiosis, how many different gametes can a diploid
animal produce based solely on independent assortment if each gamete contains 12
chromsosomes?
======
======
2 2 2 2 2 2 = 26 = 64 different gametes
Gametes are n=12, somatic cells are 2n=24. And there would be 212 or 4,096
different gametes
, 6. Zorses are the rare offspring of male zebras (2n=44) and female horses 2n=64). Assuming
no recombination during meiosis, how many genetically distcinct zorses can 2 parents
produce?
22 chromosomes in zebra gamete, 32 chromosomes in horse gamete
222 x 232 = 1.80 x 1016 different gametes
When looking for the number of different possible products take each parent and
find their distinct possibilities than multiply those 2 number together to find the total
possibilities
A male zebra can produce 222 different sperm and female horses can produce 232
differnt eggs based on independent assortment, so 2 parents could have 222 x 232 = 1.80 x
1016 unique zorses
7. Use your knowledge of meiotic division to explain why the zorses described above are
infertile?
The zorses would be infertile because there would be an unequal pairing of
chromosomes within the cell because the mother and father contriubyet different
numbers of chromosomes to the resulting cell. This would leave some of the
chromosome unpaired so when the cell divides during meiosis one of the daughter
cell would have more chromosomes than the other
Zorses have n=22 chromosomes from the zebra and n=32 from the horse, so the
chromosome cannot pair correctly and be divided evenly during mieotic division to produce
viable gametes
8. Half of your DNA came from your biological mother (egg), and half came from your
biological father (sperm), but did a quarter of your DNA ceom from each biological
grandparent?
Yes I think that ¼ of your DNA would come from your biological
grandparents because you are half of your mother and father and your mother and
father are half of their their mother and father. So that would make you are ¼ of your
biological grandparents. This also makes sense when you think about generations
because you have to in some what be related genetically to your grandparents
Due to independent assortment and recombination during meiosis in your parents, it
is unlikely that a quarter of your DNA came from you grandparents. These events of meiosis
are random so genetic testing is needed to determine grandparent contribution (varies from
15% to 35%)
9. Cavendish bananas at grocery stores came from triploid (3n) plants that are unable to
reproduce sexually. Use your knowledge of mitotic and meiotic division to explain why the
plants can be propagated asexually (by growing new plants from the stem of a parent plant)
but not sexually
The plants can be propagated asexually because the ploidy for asexual
reproduction does not matter. It would just proceed normally and produce an
exponential amount of daughter cells. The plant cannot reproduce sexually because
of the odd ploidy that is present. Because of the uneven ploidy nondisjunction will
always occur if you try to sexually reproduce
Banana plants can be propagated asexually through mitotic division, since
mitosis will produce identical muceli and does not change ploidy (3n → 3n). Meiotic
