Linkage and Recombination II (Lec 10)

Question 1

Distances on genetic maps are measured in what?

Answer 1

map units or centimorgans

Question 2

Physical maps are calculated by calculating physical distances along the chromosome, using what?

Answer 2

numbers of base pairs

Question 3

In regards to a three-point test cross, what are the types of crossovers?

Answer 3

two types of single crossovers; double crossover

Question 4

How many detectable recombinants result from a two-strand double crossover?

Answer 4

0%

Question 5

How many detectable recombinants result from a three-strand double crossover?

Answer 5

50%

Question 6

How many detectable recombinants result from a four-strand double crossover?

Answer 6

100%

Question 7

Describe how somatic-cell hybridization works?

Answer 7

1) human fibroblasts and mouse tumor cells are mixed in the presence of polyethylene glycol, which facilitates fusion of their membranes
2) … creating hybrid cells called heterokaryons
3) human and mouse nuclei in some hybrid cells fuse
4) different human chromosomes are lost in different cell lines