Complex Inheritance Patterns

Question 1

chromosome theory of inheritance:

Answer 1

genes are located on chromosomes and the behavior of chromosomes during meiosis accounts for inheritance patterns

Question 2

Exceptions to Mendel’s Laws

Answer 2

some alleles are neither dominant or recessive and many traits are controlled by multiple alleles or multiple genes

Question 3

Incomplete Dominance

Answer 3

heterozygous phenotype is somewhere between the homozygous phenotypes (neither allele is completely dom or rec)
-ex. red + white flowers = pink flowers

Question 4

Codominance

Answer 4

both traits are fully and separately expressed
-ex. red + white flowers = red and white speckled flowers
-ex. blood type AB is fully A and B

Question 5

Blood Type

Answer 5

AB, A (AA or Ai), B (BB or Bi), O (ii)

Question 6

Multiple Alleles

Answer 6

having more than 2 alleles for one gene
-ex. alleles for blood type (A, B, i)

Question 7

Polygenic Inheritance

Answer 7

a trait produced by two or more genes
-range in phenotype
-epistasis can occur (one gene overshadows all of the others)
ex. human height

Question 8

Linked Genes

Answer 8

genes that are physically located on the same chromosome will be inherited together
-ex. red hair + freckles
-can be separated/ broken apart during crossing over

Question 9

Sex-Linked Traits

Answer 9

sex chromosomes determine sex of individual
-X chromosome contains many genes that affect many traits
-Y chromosome carries few genes

Question 10

X-linked genes

Answer 10

Females inherited x-linked genes as normal, bc girls have 2 Xs

Question 11

Carrier

Answer 11

someone who carries the recessive trait but doesnt show it due to having a dominant X to mask it