Deviations from Mendelian Inheritance

Question 1

Linked genes

Answer 1

genes carried on the same chromosomes, therefore they do not assort independently

Question 2

codominance

Answer 2

both alleles are fully expressed in the phenotype

Question 3

incomplete dominance

Answer 3

the effect of one allele does not mask the affect of the other, producing blend of two parental phenotypes

Question 4

multiple alleles

Answer 4

genes with more than two alleles in the population, for ex.) the ABO blood group, a person could get any combination of A, B, O, resulting in six possible genotypic combinations

Question 5

Lethal alleles

Answer 5

-may be lethal in homozygous or heterozygous, may be dominant or recessive
-affects the mendelian ratio has homozygous genotypes are not born

Question 6

sex-linked genes

Answer 6

genes located on x or Y chromosomes (sex chromosomes)
ex.) colorblindness, hemophilia, and orange coat color in cats are X-linked conditions

Question 7

Multiple genes

Answer 7

one phenotypic trait is determined by more than one gene (polygeny) because if the way genes interact and are influence by the environment
ex.) skin color, eye color, and hair color

Question 8

Pleiotropy

Answer 8

One gene influences two or more seemingly unrelated phenotypic traits
ex.) a disorder affecting the levels of a certain type of amino acid, or more simply, a defect to one gene affects multiple systems

Question 9

Non-nuclear inheritance

Answer 9

Some DNA is inherited via mitochondria (in plants, the chloroplasts), and not via DNA ex.) all your mitochondria is inherited from your mom because the head of the sperm cell, which doesn’t have the mitochondria, is the only part that makes it into the female Oocyte (egg cell), so you only inherit your moms mitochondria

Question 10

Epigenetics

Answer 10

Highlights the roles of gene-environment interactions in gene expression; alters the way genes are read and expressed, but does not alter the gene itself

Question 11

Phenotypic plasticity

Answer 11

Varying degrees of flexibility in observable phenotype

Question 12

Random Assortment of Chromosomes

Answer 12

During meiosis, pairs of homologous chromosomes separate into haploid gametes independently of each other, leading to haploid cells with a random mix of chromosomes