sex determination

Question 1

without recombination, how many different gametes can you produce

(formula)

where n is _

Answer 1

2^n

of different chromosome pairs

Question 2

a self cross dihydrid will produce gametes in a ::: ratio for 2 different traits

with a ::: ratio

Answer 2

1:1:1:1

9:3:3:1

Question 3

if two events are not related _____

if two probabilities are mutually exclusive, you ____

Answer 3

multiply

add

Question 4

what is an example of something being mutually exclusive

Answer 4

being homozygous

if you are yy you can’t be YY, and their probabilities add because they are both homozygous

Question 5

what is it called when an organism doesn’t have sex chromosomes

how do they do instead

Answer 5

genic determination

allelic differences in a small number of loci

Question 6

what is an environmental way to determine sex

Answer 6

temperature changes

Question 7

how is sex determined in haplodiploid determination

Answer 7

males are from haploids, unfertilized eggs

females are diploid, fertilized eggs

Question 8

In slipper limpet, what determines sex

Answer 8

their position in the mollusk pyramid so they switch

Question 9

imn genotypic determination, how is sex determined

Answer 9

sex chromosomes

Question 10

the XX/X0 mode depends on the _____ distribution of the X chromosomes into ____ of the ___ gametes

when are there females in this case

Answer 10

random distribution

half of the male gametes

when they have 2 X chromosome4s

Question 11

what is homogametous pair in humans

what is heterogamous

what example is this switched and what are the variables

Answer 11

XX, female

XY, males

birds; ZZ: males, ZW: females

Question 12

What is missing in turner syndrome

what is X0 in this case

what does this prove

Answer 12

an X chromosomes

female

determined by the presence of a Y chromosome, not the number of X chromosomes

Question 13

what is wrong in Klinefelter syndrome

what are you when you have this

what does this prove

Answer 13

XXY chromosome (47 tot)

male

its the presence of Y, not the number of X

Question 14

the Y chromosome is ____ and ____ for human male development

Answer 14

necessary and sufficient

Question 15

what does SRY stand for

Answer 15

sex determining region of Y

Question 16

what does PAR stand for

Answer 16

pseudoautosomal region

Question 17

what essentially is the pseudoautosomal region

Answer 17

where the X and Y chromosomes overlap

Question 18

what sex is someone who is XY but missing the SRY on the Y chromosome

Answer 18

female

Question 19

what sex is someone who is XX but has SRY on the X chromosome

Answer 19

male

Question 20

SRY is both ____ and ____ for male development

Answer 20

necessary and sufficient

Question 21

fruit fly use XY but what determines sex

Answer 21

ratio X chromosomes to autosomes

1/2 is male

1/1 is female

Question 22

what is cross where you switch the sex of alleles on sex chromosomes

Answer 22

a reciprocal cross

Question 23

what is dosage compensation

what are 3 ways to do this and their example organisms

Answer 23

compensating gene dosage so that x-linked females will not double the expression of x linked genes

double the male expression - fruit flies

half both x chromosomes - c. elegans

inactivate one x - humans

Question 24

when one X chromosome is expressed, is it different per cell

Answer 24

yes. half may have one x expression, half may have the other half. They are quantized for changes, either one way or the other