Chapter 4 Flashcards
(30 cards)
A human with a genotype of XXY will be of which sex? Will this individual exhibit a disease syndrome and if so, which one?
Male; Klinefelter syndrome
[True or False] Sex of an individual is determined in all species by sex chromosomes
False
In xx-xy sex determination system the___is heterogamic sex, and in the zz-zw system the ___is the homogametic sex.
Male;Male
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.
SRY Genes
Who is the father of fruit fly genetics
Thomas Hunt Morgan
[True or False] A microscopic mouse egg is a single cell, but the large egg of the ostrich is composed of many cells.
False
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
Pseudoautosomal region (PAR)
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.
Turner Syndrome
What are characteristics of Turner Syndrome?
1/2500 female births
Short with low hairline
Broad chest
Folds of skin on the neck
Normal intelligence
Most are sterile
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.
Klinefelter Syndrome
What are characteristics of Klinefelter Syndrome?
1/500-1/1000 male births
Tall
Small testes
Reduced facial and pubic hair
Normal intelligence
Most sterile
The failure of homologous chromosomes to separate properly during cell division. Resulting in gametes with abnormal number of sex chromosomes
Chromosomal Nondisjunction
A genetic condition in which the body is unresponsive to androgens so that a genetic male may be born with a female-appearing body
Androgen Insensitivity Syndrome (AIS)
The term used to describe a male who possesses the single copy of a recessive diploid gene.
Hemizygous
Females are Diploid, males develop from unfertilized eggs and are Haploid. Found in Bees, Ants, and Wasps
Haplodiploidy
Where can chromosomal nondisjunction happen?
Anaphase of mitosis, meiosis l, and meiosis ll
[True or False] In case of androgen insensitivity syndrome,Individuals with the sex chromosome constitution XY appear to be female.
True
The greater degree of phenotypic variation observed in human females compared to males can be explained in large by what genetic phenomenon?
Heterozygote advantage
In humans, it is the __ that determines the sex of the child
Male (Y chromosome)
Heterozygous (carrier’s) are ____ by traits
Unaffected
Calico cats are majority
Female
All phenotypically male individuals a have a single __ and __ chromosome.
X;Y
In most species, the ___ gamete’s is larger than the ___ gamete and the __ sex chromosome contains more coding genes than the __ sex chromosome.
Female;Male; X; Y
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.
Poly-X Syndrome
