BIO 2313 Genetics
HW 4
Question 1
In wheat, kernel color is determined by additive alleles at two unlinked loci. If two plants,
one with dark red kernels (+++– genotype), and one with light red kernels (+– – –
genotype), are crossed, what fraction of the offspring is expected to have phenotypes
distinct from parental colors?
1/4
4/16
6/16
1/2
10/16
Question 2
Consider the following three-factor (trihybrid) testcross:
A+ B+ c a b c
____________________ X ________________
____________________ ________________
a b C+ a b c
| 10.6cM | 13.4cM |
Calculate the number of expected individuals of A+a bb C+c genotype if 1000
progeny result from this testcross.
About 102
, About 46
About 130
About 65
Question 3
Interference occurs when:
two genes are assorting independently.
two genes are far apart on a genetic map.
one crossover inhibits another.
the number recombinant progeny classes in the testcross of a heterozygote exceeds
the number of parental progeny.
Question 4
What is responsible for primary Down syndrome?
Disomy
Inversion
Nondisjunction
Polyploidy
Translocation
HW 4
Question 1
In wheat, kernel color is determined by additive alleles at two unlinked loci. If two plants,
one with dark red kernels (+++– genotype), and one with light red kernels (+– – –
genotype), are crossed, what fraction of the offspring is expected to have phenotypes
distinct from parental colors?
1/4
4/16
6/16
1/2
10/16
Question 2
Consider the following three-factor (trihybrid) testcross:
A+ B+ c a b c
____________________ X ________________
____________________ ________________
a b C+ a b c
| 10.6cM | 13.4cM |
Calculate the number of expected individuals of A+a bb C+c genotype if 1000
progeny result from this testcross.
About 102
, About 46
About 130
About 65
Question 3
Interference occurs when:
two genes are assorting independently.
two genes are far apart on a genetic map.
one crossover inhibits another.
the number recombinant progeny classes in the testcross of a heterozygote exceeds
the number of parental progeny.
Question 4
What is responsible for primary Down syndrome?
Disomy
Inversion
Nondisjunction
Polyploidy
Translocation
