Genetic & Inheritance

mitosis

division of somatic cells

diploid

2 copies of each chromosome = 2 alleles for every gene

meiosis

formation of germ cells - gametes

haploid

one copy of each chromosome = one allele for every gene

single gene mutation

affects 1 gene

effect of mutation depends on the type and location

effect may be conditional (depends on environmental factors)

chromosome mutation

affects multiple genes

typically causes defects

often affects multiple organ systems

epigenetic

chemical modifications of DNA that affect expression without altering sequence

i.e. DNA Methylation

autosomal inheritance

inheritance of autosomes

X-linked inheritance

inheritance of X allele

affect males more due to them only have 1 X vs females w 2 X

heterozygous females are carrier if carry the gene but not showing the trait.

inactivation causes mosaic pattern: patches of cells w different pheno- and geno-. (all the traits in the genotype is presence. often occurs in females due to XX)

cytoplasmic (mitochondrial) inheritance

inheritance of mitochondria

offsprings get the mitochondria from mothers

non-mendelian inheritance

Mitochondrial

epigenetic

genotype

AA,Aa,aa

phenotype

brown, black, tall, short, etc.

loss of function: mutation on gene

heterozygous: show effects when affecting dominant allele

homozygous recessive: show effect when BOTH is defected

homozygous dominant: show effects when affecting dominant allele

gain of function mutation

often occurs in dominant allele

WILL have defect

consanguineous relationships

inbred relationship - people from same family mate w each other

higher probability of getting genetic diseases

predict of heterozygous cross

1:2:1

halo-insufficent

only apply to loss of function mutations

meaning 1 defect allele + 1 normal allele, but the normal allele is not good enough to carry on normal function

anticipation