alleles

alternative forms of a gene

--father of modern genetics

--used pea plants to study patterns of inheritance

--diploid

--can self or cross fertilize

--are "truebreeding"

--most traits have only 2 alleles

male--anther--pollen

female--ovary--eggs

--incomplete domination

--codomination

--multiple alleles

--pleiotropy

--epistasis

--determine gender

--possess genes for other traits, especially X chromosome

--don't produce factor 8 (a protein involved in blood clotting

--more common in males

--carried recessively on X chromosome

--"royal" disease

--hemizygous-expressed with only 1 recessive copy

--chromosomes have extra or deleted material

--loss or gain of whole chromosomes

--loss or gain of whole sets of chromosomes

--trisomy 21

--1/1000 live births

--rounded face with epicanthal eye folds

--shorter than average

--heart defects

--mild to severe mental retardation

--trisomy 18

--1/8000 live births

--cleft palate/lip

--malformed/low-set ears

--receding chin

--internal/external physical deformities

--severe retardation

--tend to die within first few months

--1/20,000 live births

--severe deformities

--tiny eyes/eye openings

--cleft palate/lop

--polydactyl

--XXY

--1/1000 males

--phenotypically male

--gonads small and sterile

--secondary female sex characteristics

--taller than normal/long limbs

--rarely go bald

trisomy X

--XXX

--1/1000 females

--phenotypically female and can reproduce

--few side effects

supermale syndrome

--XYY

--1/1000

--minimum height: 6'2"/willowy

--severe acne

--some mental retardation

--used as a test for "Nature vs. Nurture"

--XO (missing 2nd sex chromosome)

--1/2000

--phenotypically female/ small gonads/ sterile

--shorter than average

--"cry of the cat" syndrome

--missing part of chromosome 5

--1/20,000

--improperly developed larynx--cat sounds

--small cranium

--severe retardation

--small, misshapen ears

--exclusively genotype

--exclusively environment

--genotype/environment interaction

--phenylaline not broken down past alkapton

--"dark urine" disease

--"one gene one polypeptide"

--not all proteins are enzymes (collagen, insulin)

--occurs in nucleus

--involves production of mRNA

basic unit of genetic information

3-letter nucleotide sequence called codons

--ribosome

--mRNA with instructions (codons)

--tRNA

--single strand of RNA

--4 H-bonding regions

--3 major loops

--amino acid bonded to 3' end

--anti-codon at opposite end from amino acid