Sex Determination

Question 1

Sex Determination in yeast (haploid)

Answer 1

-single locus on chromosome 3 called MAT

capable of switching mating type

Question 2

Sex Determination in Hymenoptera

Answer 2

• haplodiploidy
• diploid eggs = female
• haploid eggs = male

Question 3

Sex Determination in Ophryotrocha (marine annelid)

Answer 3

-developmental switch
-young are sperm-producting
mature are egg-producing

Question 4

Sex Determination in Bonnelia (marine annelid)

Answer 4

• environmental switch
• land on substrate = female
• land on female = male

Question 5

Mammals and Dipterans

Answer 5

-males ar ethe heterogametic sex

• males have heteromorphic pair (X and Y)
• females have two X-chromosomes

Question 6

Birds and Lepidopterans

Answer 6

-females are the heterogametic sex

• females have heteromorphic pair (Z and W)
• males have two Z-chromosomes

Question 7

Sex of…

XXY
XO monosomy
XXX trisomy

Answer 7

Male
Female
Male

Question 8

Sex Determination in Drosophila (Dipterans)

Answer 8

• dosage effect
• ratio of X-chromosomes to autosomal sets

<=0.5 is male
>= 1.0 is female
between 0.5 & 1.0 = intersex

Question 9

A) 2 X and 2 sets of autosomes
B) 1 X and 2 sets of autosomes
C) 1 X and 3 sets of autosomes
D) 2 X and 3 sets of autosomes

Answer 9

A) 2/2 = 1 = female
B) 1/2 = 0.5 = male
C) 1/3 = 0.33 = male
D) 2/3 = 0.67 = intersex

Question 10

Barr body

Answer 10

• condensed form (mitotic) of an X-chromosomes

- A few genes remain active