Biology sem 2 unit 3 Flashcards
Genotype
actual genetic makeup, letters are used
Phenotype
observed physical traits
homozygous
organisms that have 2 identical alleles for a particular trait
heterozygous
organisms that have 2 different alleles for the same trait
segregation
separation of alleles
allele
contrasting forms, or versions, of a gene
punnett square
a better way of finding the possible gene combinations of offsprings
homologous chromosomes
matching sets of chromosomes
haploid cell
the gametes of the reproducing organism has only one set of chromosomes (23), only found in sperm and egg cells (1N)
diploid cell
a cell that has both sets of homologous chromosomes (2N) found in body cells, 46 chromosomes
5 differences between monozygotic and dizygotic twins
Monozygotic twins are split from one cell and form from one egg and one sperm, they result in identical twins, they do not run in families, called identical twins, they have identical DNA. Dizygotic twins form from 2 eggs and are fertilized by 2 different sperm, they result in fraternal twins, they do run in families on the mothers side, called fraternal twins, they have different DNA
how do triplets form
3 separate individual eggs are fertilized by 3 separate individual sperm. 2 eggs come out of one ovary and 1 egg out the other. Or one egg splits into 3, then they’re all fraternal twins.
what does dominant mean
run in families
3 examples of dominant traits that aren’t common
widows peak, short big toe, cleft chin
girl chromosomes
xx
boy chromosomes
xy
down syndrome
(trisomy, 21) or (47,#21). 1/600 with both genders. physically- upward slanting eyes, single crease in palm, poor muscle tone, heart and kidney defects. mentally- LD, DD
Jacobs syndrome
(supermale) (47, XYY); 1/1000. physical- very tall, acne, low muscle tone. mental- LD, ADD, ADHD, aggressive behavior
turners syndrome
(45, X); 1/2000). physical- short, low hairline/ears, webbed neck, heart/kidney/thyroid problems. mental- average intelligence, LD
edwards syndrome
(trisomy 18), (47,#18); 1/8000). Most miscarry or don’t survive past 2 weeks. physical- deformed skull/jaw/ears/necks, cleft palate, webbed feet, born w/ clenched fists, heart/kidney problems. Mental- don’t make it that far
superfemale syndrome
triple X (47, XXX), 1/1000 females. physical- very tall, widely spaced eyes, kidney problems and seizures. mental- delayed speech development, LD/ADD/autism/anxiety/depression, behavior problems
patau syndrome
trisomy 13 (47,#13), 1/16000. physical- brain/spine issues, cleft palate, poorly developed eyes, polyploidy, weak. mental- severe problems. most pass in first years