Genetics Flashcards
Gene
a. Segments of DNA on a chromosome
ii. Chromatid
a. One of two identical copies of a chromosome
iii. Sister Chromatids
a. Two identical chromosomes
iv. Homologous chromosomes
a. Similar in length, gene position, and centromere location
b. Contain different alleles
iii. Lyonization
a. X-inactivation
b. One of females X chromosomes are inactivated
iv. Mosaicism
a. Two or more populations of cells with different genotypes in an individual who has developed from a single fertilized egg
b. Results from errors in cell division
c. Down Syndrome, Klinefelter syndrome, Turner syndrome
a. Thalassemia
a. Underproduction of hemoglobin
b. Methemoglobinemia
a. Cannot bind heme
c. Sickle cell disease
a. Mutated hemoglobin creates sickle shaped RBCs
mtDNA
a. Several copies of 16,569 bp, double-stranded, circular mtDNA molecule per mitochondria
b. Transcription takes place in mitochondrion, independent of nucleus
c. No introns
d. Inherited through maternal line
e. Mutation rate is 10x higher than nDNA
a. Lack of DNA reoair mechanisms
b. Damage from free radials
nDNA
a. 3.3x10^9 base pairs
b. Many introns
c. Autosomal inheritance
d. Cell cycle regulated
a. Resting mammalian cells in the G1 phase have a DNA content of?
2N
b. During S phase, the content of DNA varies between
2N and 4N
Permanent Cells
i. Remain in G0 and cannot be regenerated
ii. Cardiac muscle cells, neurons, RBCs
Stable Cells
i. Retain ability to exit the G0 phase to enter G1 when stimulated by growth factors
ii. Hepatocytes and epithelial cells of the kidney tubles