Question

Human Development-Sex Variations Individuals may acquire chromosomal sex variations, where the number and type of sex chromosomes are not average. A list of some of these variations is below. For each one, predict if the zygote would be assigned male or female or intersex at birth. Later, compare your predictions to the actual phenotypes. Zygote Phenotype Predicted Sex Sex Chromosomes Chromosomes in Gametes Sperm Egg XY Y X xX X X XO X none XYY X YY XX Y XXY XX X XXX None Y ΟΥ 1. Based upon the data, is "maleness" due to an absence of a second X chromosome or the presence of a Y chromosome? What supports your decision? 2. What genetic factor actually creates "maleness"? What is its function? 3. Besides the genetic factor, what other hormones are necessary for average male genitals to form? Where are they produced? What do they do? 4. Based upon the answers above, predict the sex of the following .. a) An individual who has XX chromosomes, with a translocated SRY gene attached to one X chromosome. b) An individual who has XY chromosomes, but the SRY gene has been permanently deleted from the Y chromosome. An individual who has XX chromosomes who is exposed to high levels of testosterone in utero due to an adrenal tumor. c)

Answer 1

1. XY :-
Predicted sex = male
Phenotype = male

2. XX:-
Predicted sex = female
Phenotype :- female

3. X0 :-
Predicted sex = female
Phenotype :- turner syndrome

4. XYY :-
Predicted sex:- super male
Phenotype :- male dominance

5. XXY :-
Predicted sex:- male
Phenotype:- Klinefelter syndrome

6. XXX:-
Predicted sex :- super female
Phenotype :- female dominance

7. OY:-
Predicted sex:- not viable
Phenotype:- not viable

1. Maleness is due to presence of Y chromosome rather than absence of a X chromosome.