Biology: Sex chromosomes/inherited

sex chromosomes

determines whether the offsprings are male or female.


non-sex chromosomes

sex linkage genes

X-linked and Y-linked genes together

Sex-limited traits

expressed in the presenece of sex hormones and are only observed in one sex or the other.

sex influenced traits

expressed in both sexes, but are expressed differently.

ex: baldness


variation of a particular inherited character


study of heredity

2 types of Intermediate inheritance

-Incomplete Dominance-Codominance

Incomplete Dominance

Both alleles are partially expressed.

example: Blending


Shows a phenotype that is a mixture of both parents. Both alleles are shown.

example: roan cows.

Polygenic Trait

many genes. 1 trait
example: height, eye color, skin color, weight.

how are eye colors determined by 3 genes?

gene 1: TONE of pigmentgene 2: AMOUNT of pigmentgene 3: POSITION of the pigment


1 gene affecting multiple traits
example: sickle cell disease