Exam 2 Flashcards
Polytene chromosomes
When many sister chromatids are fused together. Found in salivary glands of drasophilia
Testis determining factor
Protein encoded by the SRY gene. It initiates the male sex determination in humans. Genes are only found on Y chromosome
Paracentric inversion
“away from the center” inversion that does not include the centromere
Pseudoautosomal regions
Regions on the sex chromosomes that are susceptible to genetic recombination. Thus, they behave as autosomal genes rather then sex-linked.
Reciprocal translocation
Where genetic material between nonhomologous chromosomes are exchanged
Robertsonian translocation
Translocation caused by breaks near the end of acrocentric chromosomes. Results in one very large chromosome and one very small one.
Pericentric inversion
inversion that includes the centromere
Turner syndrome
A chromosome disorder in which a female is born with only one X chromosome. Mild effects because humans only have 1 active X anyway.
Androgen insensitivity
When a person is genetically male, but does not respond to male hormones
Adrenal hyperplasia
Genetic condition limiting hormone production in adrenal glands
Klinefelter syndrome
Male with development of female secondary sex characteristics. With a XXY genotype. Men may develop less hair
hemizygous
Since a male only has one copy of genes on X chromosome, males are considered hemizygous for X-linked genes
Barr bodies
The crumpled up region of DNA from an inactivated X chromosome in a female. The process is random with respect to the inactivation of the paternal or maternal X chromosome.
Aneuploidies
When an organism has an extra or missing copy of a chromosome, it is said to be aneuploid
Triple X syndrome
Females with 3 copies of X chromosome. They have female sex characteristics and are fertile.
