Question 1
The alleles of linked genes tend to ________.
◦ segregate together during gamete production
◦ assort independently
◦ be mutated more often than unlinked genes
◦ experience a higher rate of crossing over
◦ assort independently and show a higher rate of crossing over
Question 2
The order of genes on a plant chromosome is
A,
B, and
D, where A and B have a recombination frequency of 0.2, and
B and
D have a recombination frequency of 0.3. A pure-breeding plant that has the dominant
A and
D phenotypes with a recessive b phenotype is crossed to a pure-breeding plant that has the recessive a and d phenotypes with the dominant B phenotype. The resulting hybrid is crossed to a plant that has all three recessive phenotypes. Under the assumption that the value for interference in this region is zero, what percentage of each progeny type would result from a single crossover between
B and
D?
◦ 24%
ABd/ abd; 24%
abD/ abd◦ 7%
ABD/ abd; 7%
abd/ abd◦ 12%
Abd/ abd; 12%
aBD/ abd◦
50% AbD/ abd; 50%
aBd/ abd◦ 9%
ABD/ abd; 9%
abd/ abd