Variations on Mendel's Principles

Incomplete dominance

Each allele makes some contribution to the expression of a trait

heterozygous individuals have different traits than homozygous individuals

the genotypic ratio is the same as the phenotypic ratio

Example of incomplete dominance

hypercholesterolemia. each copy of the functional gene contributes to the production of LDL receptors

Multiple alleles

More than two alleles for a gene are present in a population but an indiviual can only have 2 alleles if their cells are diploid

ABO blood groups in human

IA Codes for A carboyhrate

iB codes for b Carbydrate

i

what is codominat in Ia and Ib

becasue they are are both expressed when found together, i is recessive

universal recipient?

type ab no antibodies agistst it

type o is a

universal donor

what are the possible blood types for children of partent with blood b and blood a

4 different types of blood has a reciecessive i

there are multiple copies of the same gene in different locations on the chromosomes result in?

chromosomal duplication and translocation

hair colour results of two pigments

1. eumelanin - brown to black

2. promeanin - eumelanin masks the presence of promelanin