ged 11

Question 1

what are autosomes

Answer 1

non sex chromsomes

Question 2

where is the pseudoautosomal region found and what is its purpose

Answer 2

found at the tips of the two sex chromosomes and allows for pairing between the x and y chrosmomes during meiosis

Question 3

what is meant by homogametic

Answer 3

females only make on type of gamete, X

Question 4

what is meant by heterogametic

Answer 4

male sex chromsomes can either be an x or a y

Question 5

what is aneuploidy

Answer 5

having an abnormal number of chromosomes eg XO or xXY male

Question 6

is all of the y chromosome required to confer maleness

Answer 6

NO, just the SRY, the sex determining region on the Y

Question 7

how does the SRY gene confer maleness

Answer 7

SRY is a dna binding protein ie a transcription factor, regulates the genes needed for testis formation

Question 8

males are hemizygous for genes on the x chromosome what does this mean

Answer 8

they don’t have the corresponding gene on the y chromsome

Question 9

what is a gyandromorph

Answer 9

has features of both males and females

Question 10

birds have a zw system whats the chromsomes for a female and a male

Answer 10

zz male

zw female

Question 11

what is dosage compensation

Answer 11

one of the x chromosomes becoming inactivated to make half their gene dosage

Question 12

what is a barr body

Answer 12

a highly condensed, non expressive inactivated X chromosome

Question 13

x chromosome inactivation in mammals can happen to

Answer 13

either of the X chromoosomes, the mothers x or the fathers x

Question 14

female mammals are mosaic what does this mean

Answer 14

some of their cells have an active X from the father or their cells could have an active maternal chromsome