BIOD 210 GENETICS
Exam MODULE 4 Questions and
Ansẉers
2026\2027 update
1. Q: What is genetic linkage?
ANSWER The tendency of DNA sequences that are close together on
a chromosome to be inherited together.
2. Q: Who first provided evidence for genetic linkage?
ANSWER Thomas Hunt Morgan, through his work with Drosophila
(fruit flies).
3. Q: What is a linkage group?
ANSWER A group of genes whose loci are on the same chromosome
and therefore do not assort independently.
4. Q: What is recombination?
ANSWER The exchange of genetic material between homologous
chromosomes during meiosis (crossing over).
5. Q: What is a recombinant gamete?
ANSWER A gamete that has a combination of alleles different from
the combinations found in the parental gametes.
, 6. Q: What is recombination frequency?
ANSWER The proportion of recombinant offspring produced in a
genetic cross relative to the total number of offspring.
7. Q: What is the maximum recombination frequency for two genes?
ANSWER 50%, which indicates the genes assort independently (are
on different chromosomes or far apart on the same one).
8. Q: How is recombination frequency used to map genes?
ANSWER It is used as a measure of physical distance; 1%
recombination frequency is equal to 1 map unit (centimorgan, cM).
9. Q: What is a centimorgan (cM)?
ANSWER A unit of measure for genetic distance, equal to 1%
recombination frequency.
10. Q: What is a testcross in the context of linkage?
ANSWER Crossing a heterozygote for two linked genes with a
homozygous recessive individual to determine the frequency of
recombinant gametes.
11. Q: What is a parental (non-recombinant) gamete?
ANSWER A gamete with the same allele combination as one of the
parents' gametes.
12. Q: What is a two-point test cross?
Exam MODULE 4 Questions and
Ansẉers
2026\2027 update
1. Q: What is genetic linkage?
ANSWER The tendency of DNA sequences that are close together on
a chromosome to be inherited together.
2. Q: Who first provided evidence for genetic linkage?
ANSWER Thomas Hunt Morgan, through his work with Drosophila
(fruit flies).
3. Q: What is a linkage group?
ANSWER A group of genes whose loci are on the same chromosome
and therefore do not assort independently.
4. Q: What is recombination?
ANSWER The exchange of genetic material between homologous
chromosomes during meiosis (crossing over).
5. Q: What is a recombinant gamete?
ANSWER A gamete that has a combination of alleles different from
the combinations found in the parental gametes.
, 6. Q: What is recombination frequency?
ANSWER The proportion of recombinant offspring produced in a
genetic cross relative to the total number of offspring.
7. Q: What is the maximum recombination frequency for two genes?
ANSWER 50%, which indicates the genes assort independently (are
on different chromosomes or far apart on the same one).
8. Q: How is recombination frequency used to map genes?
ANSWER It is used as a measure of physical distance; 1%
recombination frequency is equal to 1 map unit (centimorgan, cM).
9. Q: What is a centimorgan (cM)?
ANSWER A unit of measure for genetic distance, equal to 1%
recombination frequency.
10. Q: What is a testcross in the context of linkage?
ANSWER Crossing a heterozygote for two linked genes with a
homozygous recessive individual to determine the frequency of
recombinant gametes.
11. Q: What is a parental (non-recombinant) gamete?
ANSWER A gamete with the same allele combination as one of the
parents' gametes.
12. Q: What is a two-point test cross?
