04b: Genetics Flashcards
(X) are the vehicles for genes.
X = chromosomes
We have how many pairs of chromosomes?
23 pairs
Meiosis produces (haploid/diploid/polyploid) cells.
Haploid (1n)
Turner’s syndrome has (X) karyotype, which indicates (extra/missing):
X = XO
Missing sex chromosome
A small change in number of chromosomes has what effect on genes?
Changes hundred to thousands of genes
Gene mutations can be found in which specific parts of gene?
Anywhere! (Promoter region, exons, introns, etc)
In meiosis I, (X) separate. And in meiosis II, (Y) separate.
X = homologous chromosomes
Y = sister chromatids
What’s the sum rule?
Determine probability of normal offspring by:
P (homozygous normal) + p (heterozygous normal)
What’s the law of independent assortment?
Individual hereditary factors assort independently of each other
Is there an exception to law of independent assortment?
Yes - linked genes
Describe meiotic recombination.
Shuffling of genetic components between homologs
Probability of recombination between two genetic (X) is directly proportional to:
X = loci
Physical distance that separates them on chromosome
Two genes closer together are (more/less/equally) likely to undergo recombination than two genes further apart.
Less likely
In (X), each genotype has a different phenotype.
X = Incomplete dominance
Crossing red and white flowers gives some pink flowers. This is example of:
Incomplete dominance
Inheritance of Hyperlipoproteinemia follows rules of incomplete dominance. Heterozygous phenotype would be:
Mild case of disease
Give example of Codominance.
Blood type
What’s the difference between Codominance and incomplete dominance?
Codominance shows simultaneous expression of both alleles, not a blend of traits.
What’s incomplete penetrance?
Having certain genotype means there’s
What are phenocopies?
Two different phenotypes that look identical, but one case is inherited while the other is sporadic
Albinism is an example of (X), where (Y) gene(s) mutated results in multiple affected systems.
X = pleiotropy
Y = one
We must fit (X) length of DNA into a nucleus of what size?
X = 2 m
Nucleus of 6 micrometers
Addition of acetyl groups on (X) will (open/close) chromatin. Why?
X = Histone tail
Open;
Neutralizes Lys, decreasing attraction of Histone to DNA backbone
T/F: If a methylated DNA strand is replicated, there’s maintenance of methylation on copy strand.
True
A (methylated/unmethylated) CpG and (acetylated/deacetylated) Histone gene is OFF.
Methylated; deacetylated
A (methylated/unmethylated) CpG and (acetylated/deacetylated) Histone gene is ON.
Unmethylated; acetylated
Imprinting refers to:
Genes inherited with different methylation states (from each parent)
