Biology: Sex chromosomes/inherited


sex chromosomes


determines whether the offsprings are male or female.


autosomes


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


trait


variation of a particular inherited character


genetics


study of heredity


2 types of Intermediate inheritance


-Incomplete Dominance-Codominance


Incomplete Dominance


Both alleles are partially expressed.

example: Blending


Codominance


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


Pleiotropy


1 gene affecting multiple traits
example: sickle cell disease