L11

Question 1

what does the term sex refer to

Answer 1

the phenotype of the individual

Question 2

what you call the mechanism in which sex is determined

Answer 2

sex determination

Question 3

how is sex determined, what are the 3 ways

Answer 3

chromosomally, genetically, or environmentally

Question 4

true or false, in many organisms sex is determined by a pair of chromosomes, the sex chromosomes, which differ between males and females

Answer 4

true

Question 5

true or false, some organisms it is the genes located on the sex chromosome which determines that organisms’ sex

Answer 5

true

Question 6

what are the 5 types of sex determining mechanisms

Answer 6

XX - XO (male X) common in insects
XX-XY (male XY) common in humans
ZZ-ZW (male ZZ) common in avians

genic sex determination
environmental sex determination

Question 7

what is the sex chromosome combination of a person with Klinefelters

Answer 7

XXY

Question 8

what is the sex chromosome combination of a person with Turners Syndrome

Answer 8

XO

Question 9

which syndromes led to the identification of the Y chromosome carrying the genetic information for maleness

Answer 9

Turner’s and Klinefelters

Question 10

true or false, the male sex chromosome is smaller than the female X chromosome

Answer 10

true

Question 11

true or false, primary pseudoautosomal region, is on the short arm of the chromosome and where they are homologous in sequence

Answer 11

true

Question 12

true or false, secondary pseudoautosomal region, is on the long arm, allows crossing over and pairing at those regions of the two chromosomes

Answer 12

true

Question 13

what do you call the factor that is responsible for initiating testis formation present on the Y chromosome

Answer 13

testis determining factor TDF

Question 14

what do you call the male sex determining gene

Answer 14

SRY ( sex determining region Y)

Question 15

true or false, the SRY gene is a transcription factor

Answer 15

true

Question 16

what does the SRY gene encode for

Answer 16

the protein which binds to DNA and stimulate the transcription of other genes that promote the development of the testes

Question 17

true or false, AIS is an X linked gene

Answer 17

true

Question 18

what do you call the genes which encode for 60% similarity to SRY

Answer 18

SOX genes

Question 19

true or false, the SOX-9 gene is highly conserved throughout the vertebrate groups

Answer 19

true

Question 20

true or false, SOX-9 is at low levels in male and female genital ridge but is then up regulated in males and turned off in female gonads

Answer 20

true

Question 21

true or false, SOX-9 cooperates with the other genes to activate the expression of Anit-Mullerian hormone (AMH)

Answer 21

true

Question 22

true or false, SOX-9 is a transcirption factor which is the master regulator of Sertoli cell differentiation

Answer 22

true

Question 23

what happens when DMNT1 is turned off in males

Answer 23

the males will turn back into females

Question 24

what is the normal function of DMNT1, blocks the activity of female genes, enhancing male genes activity

Answer 24

true

Question 25

what is dosage compensation

Answer 25

equalizes the amount of protein produced by the X chromosome; since protein concentration plays an important role in development