Chromosome Mapping In Eukaryotes - Concepts of Genetics

Which of the following scenarios would erroneously lead you to believe two genes reside on different chromosomes when they in fact are on the same chromosome?

A)the genes are very far apart on the same chromosome,such that there is always a crossover between them
B)the genes are very close together on the chromosome,such that there is never a crossover between them
C)too large a sample size
D)the genes are very far apart on the same chromosome,such that there is never a crossover between them
E)a mating between consanguineous individuals

Answer

Question 2

(Multiple Choice)

Free

The genes for purple eyes and curved wings are approximately 21 map units apart on chromosome II in Drosophila.Assume that a purple-eyed female was mated to a curved wing male and that the resulting F₁ phenotypically wild-type females were mated to purple,curved males.Of 1000 offspring,what would be the expected number of flies with purple eyes and curved wings?

A)540
B)395
C)210
D)790
E)105

Answer

Question 3

(Multiple Choice)

Free

The cross GE/ge × ge/ge produces the following progeny: GE/ge 404; ge/ge 396; gE/ge 97; Ge/ge 103.From these data,one can conclude that .

A)the G and E loci are segregating independently
B)the G and E loci are linked
C)the G and E loci reside on the same chromosome over 50 map units apart
D)the G and E loci show complete linkage
E)the G and E loci assort independently

Answer