Key concepts
Hereditary
environment also affects traits
genes define traits
example: sunlight changes hair and skin color
Trait
each human has two complete sets of chromosomes (23 each)
children have a set from each parent
when sperm joins with egg, ZY-goat created
child's set can have chromosomes from parent's two sets, but only one of each chromosome
passed from generations
physical traits
hair color, height, eye color
behavioral traits
the way someone behaves
medical
higher risks of certain illnesses
affected by sun, pollution
affected by living conditions, family, traumatic events
affected by food, pollution
determined by having two of the same allele (homozygous)
two different alleles, H allele maks h allele
H = domunate, h = recessive
heterozygous = two different alleles
parents give one of their two alleles to child
traits influenced by one gene = uncommon (single-gene traits)
traits influenced by several = complex traits
DNA
are the "instructions"
stands for DeoxyriboNecleicAcid
shape of a double helix
DNA alphabet: ACTG
A always pairs with T, C always pairs with G
makes letters, letters make words, words make sentences
sentences = genes