linkage and chromosome mapping in eukaryotes

Question 1

homologous chromosomes segregate at …. to form haploid gametes

Answer 1

meiosis

Question 2

number of possible combinations of chromosomes in each haploid gamete

Answer 2

2 to the power 23
-2 chromosomes in diploid organism
-23 number of different chromosomes

Question 3

ways of creating combinations of genetic characteristics in offspring (2)

Answer 3

-independent assortment
-homologous recombination events that occur between non-sister chromatids during meiosis - crossing over of genetic material

Question 4

crossing over is reciprocal -

Answer 4

segments exchanged by non-sister chromatids are identical on 2 different non-sister chromatids

Question 5

why must crossing over (homologous recombination) be done with great precision

Answer 5

so that both non-sister chromatids gain or lose genes
-not a single nucleotide is lost or added at the crossover point

Question 6

how is crossing over inheritance not Mendelian

Answer 6

crossing over at meiosis produces new gene combinations

Question 7

the closer the genes are on a chromosome -

Answer 7

the less chance of crossing over at meiosis, more likely the 2 alleles of the 2 neighbouring genes are inherited together

Question 8

recombination progeny allows us to

Answer 8

map the distance between genes

Question 9

calculate recombination frequency =

Answer 9

no. of recombinants/total no. of progeny x 100

Question 10

meiosis of human gametes - how many chiasma between non-sister chromatids

Answer 10

1-3