Part B: Lecture 7

Question 1

Nomenclature for genotype: prokaryotes

Answer 1

a+ b- c+ (list of genes they have)

Question 2

Nomenclatures for genotype: eukaryotes

Answer 2

1. gene location on homologous chromosomes + centromeres
2. gene location on homologous chromosomes without centromeres
3. genes on homologous chromosomes (fraction-style)
4. typeable

Question 3

Typeable nomenclature for genotype: eukaryotes

Answer 3

/ –> homologous chromosomes
; –> different chromosome
. –> don’t know if on same chromosomes or different chromosomes
gene order must stay consistent

ex. a+ b-/ a- b+ ; c+ / c-

Question 4

Lifecycle of Drosophila (3-4 days)

Answer 4

-embryo
-first instar larva
-second instar larva
-third instar larva
-pupa

Question 5

the purpose of alternating between haploid + diploid

Answer 5

-produce offspring with new allele combinations

Question 6

outcome of mitosis: genotype

Answer 6

-same chromosomes, genes and alleles

Question 7

outcome of meiosis + fertilization : genotype

Answer 7

-same chromosomes, same genes and different alleles

Question 8

offspring of meiosis will have both ___ combinations of alleles

Answer 8

parental & new recombinant

Question 9

offspring of meiosis may potentially have _____

Answer 9

favorable allele combinations

Question 10

Recombination happens in what phase of meiosis?

Answer 10

prophase I (late prophase specifically)

Question 11

Recombination process

Answer 11

1. Homologous chromosomes par at the beginning of prophase I
2. DNA breaks at identical sites on two non-sister chromatids
3. DNA s repaired but ‘wrong’ ends are joined

Question 12

major function of meiotic crossovers

Answer 12

-hold homologous chromosomes together during meiosis I

Question 13

minor function of meiotic crossovers

Answer 13

-produce recombinant offspring

Question 14

crossover can happen between ___

Answer 14

any two non-sister chromatids