chapter 14: mendel and the gene idea

a heritable feature of an organism

different variations of a character

parental generation, original generation, true-breeding

offspring of P generation

self-pollinated offspring of F1 generation

cross genetically different organisms

the specific location of an allele on a chromosome

an organism having a genotype with the same alleles for a gene

an organism having a genotype with different allels for a gene

a genotype with multiple phenotypic effects

one gene on a locus affecting the expression of a different gene on a different locus

the range of phenotype expression for a genotype

alternative versions of a gene

one allele from each parent

overrules other alleles

can be ruled over by different alleles

• phenotype is what is seen or expressed

• genotype is the actual genetic code

• used to determine the genotype of an unknown organism with a dominant appearance with a homozygous recessive organism

2 alleles are going to segregate into 2 different gametes

• genotype= 1:2:1 (1 homo dom, 2 hetero, 1 homo rec)

• phenotype= 3:1 (3 dom, 1 rec)

each pair of alleles separating into different gametes is unaffected by other pairs of alleles

first meiosis division

probability of 2+ independent event occurring together

probability of 1-2 mutually exclusive events occurring together

the phenotype of the offspring is somewhere between the parental phenotypes

2 dominant traits are seen in separate, distinguishable ways

• the phenotype of trait is on a scale

• usually indicate polygenic inheritance

• even if the genotype is the same between organisms, the organism’s phenotype can still be changed/adjust based on the environment

• e.g. flower color changing based on soil acidity

• most common lethal genetic disorder

• makes chloride transport channels ineffective or absent

• causes buildup of mucus in different organs

• 1 amino acid substituted

• changes red-blood cell shape

• degenerative disease of nervous system

• doesn’t appear until 30s-40s

• disorder that has genetic and environmental factos

• e.g. smoking increases lung cancer risk