Chapter 4

Question 1

A human with a genotype of XXY will be of which sex? Will this individual exhibit a disease syndrome and if so, which one?

Answer 1

Male; Klinefelter syndrome

Question 2

[True or False] Sex of an individual is determined in all species by sex chromosomes

Answer 2

False

Question 3

In xx-xy sex determination system the___is heterogamic sex, and in the zz-zw system the ___is the homogametic sex.

Answer 3

Male;Male

Question 4

What is the sex determining gene of the Y chromosome in males. Encodes the testis-determining factor, which turns the primordial gonads into the testes.

Answer 4

SRY Genes

Question 5

Who is the father of fruit fly genetics

Answer 5

Thomas Hunt Morgan

Question 6

[True or False] A microscopic mouse egg is a single cell, but the large egg of the ostrich is composed of many cells.

Answer 6

False

Question 7

The x and Y chromosomes are able to pair up during meiosis because of the presence of regions of homology on the 2 chromosomes known as

Answer 7

Pseudoautosomal region (PAR)

Question 8

A chromosomal disorder in females in which either an X chromosome is missing, making the person XO instead of XX, or part of one X chromosome is deleted.

Answer 8

Turner Syndrome

Question 9

What are characteristics of Turner Syndrome?

Answer 9

1/2500 female births
Short with low hairline
Broad chest
Folds of skin on the neck
Normal intelligence
Most are sterile

Question 10

A chromosomal disorder in which males have an extra X chromosome, making them XXY instead of XY. At least two X chromosomes and one Y chromosome.

Answer 10

Klinefelter Syndrome

Question 11

What are characteristics of Klinefelter Syndrome?

Answer 11

1/500-1/1000 male births
Tall
Small testes
Reduced facial and pubic hair
Normal intelligence
Most sterile

Question 12

The failure of homologous chromosomes to separate properly during cell division. Resulting in gametes with abnormal number of sex chromosomes

Answer 12

Chromosomal Nondisjunction

Question 13

A genetic condition in which the body is unresponsive to androgens so that a genetic male may be born with a female-appearing body

Answer 13

Androgen Insensitivity Syndrome (AIS)

Question 14

The term used to describe a male who possesses the single copy of a recessive diploid gene.

Answer 14

Hemizygous

Question 15

Females are Diploid, males develop from unfertilized eggs and are Haploid. Found in Bees, Ants, and Wasps

Answer 15

Haplodiploidy

Question 16

Where can chromosomal nondisjunction happen?

Answer 16

Anaphase of mitosis, meiosis l, and meiosis ll

Question 17

[True or False] In case of androgen insensitivity syndrome,Individuals with the sex chromosome constitution XY appear to be female.

Answer 17

True

Question 18

The greater degree of phenotypic variation observed in human females compared to males can be explained in large by what genetic phenomenon?

Answer 18

Heterozygote advantage

Question 19

In humans, it is the __ that determines the sex of the child

Answer 19

Male (Y chromosome)

Question 20

Heterozygous (carrier’s) are ____ by traits

Answer 20

Unaffected

Question 21

Calico cats are majority

Answer 21

Female

Question 22

All phenotypically male individuals a have a single __ and __ chromosome.

Answer 22

X;Y

Question 23

In most species, the ___ gamete’s is larger than the ___ gamete and the __ sex chromosome contains more coding genes than the __ sex chromosome.

Answer 23

Female;Male; X; Y

Question 24

A chromosomal disorder where females are born with one or more extra X chromosomes, usually fertile since X chromosomes will be converted into Barr bodies, prone to mental retardation.

Answer 24

Poly-X Syndrome

Question 25

Chromosomal disorder with single X chromosome

Answer 25

Turner Syndrome

Question 26

Chromosomal disorder with at least two X or Y chromosomes
(XXY, XXXY, XXYY)

Answer 26

Klinefelter Syndrome

Question 27

Chromosomal disorder with multiple X chromosomes
(XXX, XXXX, XXXXX)

Answer 27

Poly-X Syndrome

Question 28

T/F: The sex of an individual is determined in all species by sex chromosomes

Answer 28

False

Question 29

Joe has classic hemophilia, an X-linked recessive disease. The allele Joe inherited for this disease could have originated in which of the following persons?

Answer 29

His mother’s mother or father

Question 30

In the XX-XY sex determination system, the ____ is the heterogametic sex and in the ZZ-ZW system the ___is the homogametic sex.

Answer 30

Male;Male