Genetics Test Study Guide

the DNA that codes for a trait

the different forms of the same trait

Dominant Allele
the stronger allele, only need one cope to show the trait

Recessive allele
the weaker allele, need two copies to show the trait

actual genes for a trait

the physical appearance of a trait

two of the same alleles

Homozygous dominant

Homozygous recessive

two different alleles

Law of Segregation
Traits come in pairs
Alleles separate into gametes during reproduction

Law of Independent Assortment
One trait does not affect the inheritance of another

Mendel’s Laws
Law of Segregation
Law of Independent Assortment

Di-hybrid Cross Genotype Ratio
Dom,Dom: Dom, rec: rec,Dom: rec, rec

Sex – linked Traits
Gene is carried on X or Y chromosome

Rule of Multiplication
Probability that 2 or more events will occur the same way

Rule of Addition
Probability that an event will occur in 2 or more ways

when both alleles are dominant; you see both phenotypes

Incomplete Dominance
when neither allele is completely dominant over the other; you see the intermediate

Blood Groups
Example of Co-dominance

Red flower plus white flower = pink flower
Example of Incomplete Dominance