Questions and Verified Answer Graded A+ 2024
Proportion of offspring with both kinds of crossover equation - ANSWER P(crossover
between C and A)xP(crossover between A and B)
Interference - ANSWER The presence of one crossover prevents other crossovers
from occurring nearby.
Coefficient of Interference: I equation - ANSWER I=1-(observed frequency/expected
frequency of double crossovers)
What is the max recombination frequency? - ANSWER 50% no matter if the distance
between the genes are greater than 50cM apart.
What did Mendel's experiments suggest? - ANSWER 1. 2 types of alleles exist for
every gene
2. Alleles maintain their integrity in each generation (no blending)
3. In the presence of dominant allele, the recessive allele is hidden with no contribution
to the phenotype.
Pleiotropic - ANSWER Genes that control multiple seemingly unrelated features.
How was the chromosomal theory of inheritance consistent with Mendel's law? -
ANSWER 1. During meiosis homologous chromosome pairs migrate as discrete
structures that are independent of other chromosome pairs
2. The sorting of chromosomes from each homologous pair into pre-gametes appears to
be random.
3. Each parent synthesizes gametes that contain only half of their chromosomal
complement.
4. Even though male and female gametes differ in size and morphology, they have the
same # of chromosomes suggesting equal genetic contributions from each parent
5. The gametic chromosomes combine during fertilization to produce offspring with the
same chromosome # as their parents.
Null Hypothesis (H0) - ANSWER The default or general position, assumes Mendel
was right.
There is no association between two phenomena
There is no effect by a drug on a disease
There is no linkage between two genes
There is no evolution occurring in the gene pool
Loss of function Mutations - ANSWER Cause a gene to lose some or all of it's normal
function
, Hypomorphic mutations - ANSWER Genes that have lost only some of their function
Null mutations - ANSWER Genes that have lost all of their function
Haplo-sufficient - ANSWER One (haplo) copy is sufficient to produce the wild-type
phenotype in the heterozygous genotype
Fully dominant mutations - ANSWER Phenotype of a fully dominant mutation is seen
in both heterozygous and homozygous dominant individuals.
Gain-of-function - ANSWER gene product acquires a new function or express
increased wild type activity
Loss-of-function - ANSWER there is a significant decrease or complete loss of
functional gene product
Incomplete dominance - ANSWER phenotype of the heterozygote is intermediate
between the phenotypes of the two homozygotes on some quantitative scale (color,
size, etc)
Codominance - ANSWER Phenotypes of both alleles are fully expressed in the
heterozygote and leads to a different phenotype than either homozygotes.
Allelic series of the C gene - ANSWER Wild type allele: C, produces full coat color
c^ch: produces a dilute phenotype, chinchilla
c^h: produces phenotype called Himalayan with little pigment on the body but full color
on the extremities (non functional at higher body temps).
c:Fully recessive, null allele and produces an albino phenotype
complementation tests - ANSWER Determine if mutations that cause the same
phenotype are in the same or different genes.
Epistatic interactions - ANSWER when 2 or more genes affect the same phenotype
by influencing a common pathway.
Epistatic gene interaction ratios - ANSWER None 9:3:3:1
Complementary 9:7
Duplicate 15:1
Dominant 9:6:1
Recessive epistatic 9:3:4
Dominant epistasis 12:3:1
Dominant suppression 13:3