11.3: Inheritance patterns are often more complex than predicted by simple Mendelian genetics

Question 1

complete dominance

Answer 1

where the phenotype of the heterozygote and the dominant homozygotes are indistinguishable

Question 2

incomplete dominance

Answer 2

where the F1 hybrids have a phenotype between the 2 parental varieties, use capital letters with a superscript, pink

Question 3

codominance

Answer 3

the 2 alleles each affect the phenotype in separate ways, they both happen, blood alleles (AB)

Question 4

Tay-Sachs’s disease

Answer 4

where the brain can’t do certain things, only happens in homozygotes with the recessive allele, in heterozygotes, it does nothing but is codominant at the molecular level

Question 5

Multiple alleles? What are the 3 possible alleles for blood types?

Answer 5

In the whole population,
some genes have more
than two alleles

I^A, I^B, and i, A person’s blood group may be one of 4 types, A, B, AB, or O(carbohydrates)

Question 6

pleiotropy

Answer 6

property of genes that allow them to have multiple phenotypic effects, Ex: sickle-cell and cystic fibrosis, Be BE, be, bE, same on each side

Question 7

What are the 2-situation examined in which 2 or more genes are involved in determining a particular phenotype?

Answer 7

epistasis and polygenic inheritance

Question 8

epistasis

Answer 8

the phenotypic expression of a gene at one locus alters that of a gene at a second locus, Ex: black or brown fur (Bb), this does not matter due to the gene for pigment deposition(ee) which is epistatic

Question 9

multifactorial

Answer 9

many factors including the genetic and environmental influence the phenotype

Question 10

norm of reaction

Answer 10

the phenotypic range of a genotype influenced by the environment

Question 11

polygenic inheritance

Answer 11

an additive effect of two or more genes on a single phenotype character

Question 12

multiple genes

Answer 12

some genes have more than 2 alleles