Sex linked traits

Question 1

when traits are inherited on autosomes, what is the likleyhood of a male of female inheriting the trait?
when they’re inherited on sex chromosomes, what happens to the likleyhood of inheritance? why?

Answer 1

-equal for males and females
-not equal since human females have 2 x chromosomes and males only have 1

Question 2

-who provided a depper understanding of gender and traits?
-What experiment did he conduct, and what did he notice? What were the gender numbers?

Answer 2

Thomas hut Morgan
-breeding of fruit flies (they reproduce quick, short life, small and easy to distinguish)
-he noticed many mutations (white eyes) that was ONLY present in males among many red eyed females

Question 3

What flies did he cross for the experiment, and what did the F1 gen have?
-when he crossed the F1 gen, what did the F2 gen have?
-white eyes were only in _______.
-what did he conclude about the traits governing eye colour?
-eye colour is a _____ ________ trait, located on what?

Answer 3

-white eyed male and red eye female. all F1 had red eyes.
-F2 3/4 had red eyes and 1/4 had white
-MALE
-they were located on the X chromosome
-sex linked trait, located on sex chromosomes

Question 4

-Size comparison of Y and X chromosome. Are they homologous?
-What does the SRY gene do?
-what are 3 common sex linked genes in humans?

Answer 4

-Y is much smaller. No.
-the Sex determining region Y gene is on the Y chromosome that activates testes development
-colour blindness for red green, dechene muscular dystrophy, hemophilia (all X linked recessive)

Question 5

X inactivation in Females
-do females have twice as much genetic info since theyhave 2 X chromosomes?
-what happens to 1 of the X’s
-What happens to the inactivated X in each cell
-selection of which X chromosome becomes the Barr body occurs ________ and _______ in each cell
-therefore, females consist of a _____ of 2 types of cells: ?

Answer 5

-No, they are equal in egnes
-one of them inactivates during embryo dev.
-it becomes a compact Barr body (dormant X chromosome)
-radomly and indepdendently
-mosaic of those with the active X from father and active X from mother