Genetics exam test queries and
answers graded A+
Much of what we know about genetic linkage comes from studies of the fruit fly, Drosophila
melanogaster. Which of the following is most responsible for the fact that what we learned from
Drosophila applies to humans?
A. Drosophila chromosomes look a lot like human chromosomes in a microscope
B. Both human and Drosophila chromosomes are made of DNA and proteins
C. Humans and Drosophila share a common evolutionary ancestor that had the same basic
mechanisms of meiosis and recombination
D. We're not sure - it is mostly luck that early studies focused on Drosophila melanogaster -
ANS✅✅c
Within a single species: What is the difference between a haploid cell and a diploid cell? -
ANS✅✅# of copies of each chromosome
haploid vs diploid - ANS✅✅haploid: every chromosome is different
diploid: chromosomes are in pairs
A pair of homologous chromosomes
A. normally have the same genes in the same order as each other
.B. normally are identical.
C. are present only after S-phase.
D. are attached to a single centromere in Metaphase I - ANS✅✅a
The figure shows a dog karyotype (not just any dog - my dog Penny). Which statement is a correct
way to phrase the dog karyotype?
A. 2n = 38
B. 2n = 76
C. n = 76
D. 2n = 46 - ANS✅✅b
The chromosome complement of Canis familiar is is written as 2n=76
, What does 'n' refer to? - ANS✅✅# of chromosomes in a haploid cell
sister chromatids variation - ANS✅✅little to no variation
variation= mutation
homologous pairs variation - ANS✅✅more variation
variation: heterozygosity
During the cell cycle, when does DNA replication occur?
A. G0
B. G1
C. M
D. S - ANS✅✅d
During meiosis, which cell division reduces the cell(s) from diploid to haploid?
A. The first
B. The second - ANS✅✅a
When counting chromosomes in a cell, which part of the chromosome should you count? -
ANS✅✅centromere
homologous pair - ANS✅✅one chromosome, two chromatids
When does a chromosome consist of two sister chromatids? - ANS✅✅after S phase but before
anaphase II
When does a chromosome consist of one chromatid? - ANS✅✅any other time
Why is the structure with two sister chromatids still just one chromosome? - ANS✅✅only one
centromere
answers graded A+
Much of what we know about genetic linkage comes from studies of the fruit fly, Drosophila
melanogaster. Which of the following is most responsible for the fact that what we learned from
Drosophila applies to humans?
A. Drosophila chromosomes look a lot like human chromosomes in a microscope
B. Both human and Drosophila chromosomes are made of DNA and proteins
C. Humans and Drosophila share a common evolutionary ancestor that had the same basic
mechanisms of meiosis and recombination
D. We're not sure - it is mostly luck that early studies focused on Drosophila melanogaster -
ANS✅✅c
Within a single species: What is the difference between a haploid cell and a diploid cell? -
ANS✅✅# of copies of each chromosome
haploid vs diploid - ANS✅✅haploid: every chromosome is different
diploid: chromosomes are in pairs
A pair of homologous chromosomes
A. normally have the same genes in the same order as each other
.B. normally are identical.
C. are present only after S-phase.
D. are attached to a single centromere in Metaphase I - ANS✅✅a
The figure shows a dog karyotype (not just any dog - my dog Penny). Which statement is a correct
way to phrase the dog karyotype?
A. 2n = 38
B. 2n = 76
C. n = 76
D. 2n = 46 - ANS✅✅b
The chromosome complement of Canis familiar is is written as 2n=76
, What does 'n' refer to? - ANS✅✅# of chromosomes in a haploid cell
sister chromatids variation - ANS✅✅little to no variation
variation= mutation
homologous pairs variation - ANS✅✅more variation
variation: heterozygosity
During the cell cycle, when does DNA replication occur?
A. G0
B. G1
C. M
D. S - ANS✅✅d
During meiosis, which cell division reduces the cell(s) from diploid to haploid?
A. The first
B. The second - ANS✅✅a
When counting chromosomes in a cell, which part of the chromosome should you count? -
ANS✅✅centromere
homologous pair - ANS✅✅one chromosome, two chromatids
When does a chromosome consist of two sister chromatids? - ANS✅✅after S phase but before
anaphase II
When does a chromosome consist of one chromatid? - ANS✅✅any other time
Why is the structure with two sister chromatids still just one chromosome? - ANS✅✅only one
centromere
