Unit 5: Heredity Unknown Info (AP Biology 2026) Flashcards

when a haploid sperm cell fuses with haploids egg cell

all somatic cells have copies of all of the zygote's 46 chromosomes

same centromere location, length, genes, banding pattern (zebra stripes)

cellular reproduction / division

the cell is the smallest living unit of all organisms, all living things are made of cells, all cells come from pre-existing cells

produces daughter cells via meiosis or mitosis

prokaryotic cell division; plasma membrane and cell wall grow inward to divide in half after DNA is doubled

single chromosomes, circular, smaller, simpler

new plasma membrane grows between 2 sites where chromosome duplicates are attached OR chromosomes actively move away via unknown mechanism

SPECIFICALLY the protein structure each sister chromatid has, which holds chromosomes together at centromere

where the sister chromatids join together

another name for meiosis

when sperm cells are made

when eggs are made, produces only ONE ovum, other 3 are polar bodies

the other 3 cells produced, degenerate since have very little cytoplasm (females conserve as much for the one ovum)

surviving gamete in oogenesis

crossing over (P1), independent chromosome orientation (M1), random fertilization, chromosomal nondisjunction, chromosomal mutations

the random / independent arrangement of homologous chromosomes (tetrads) at metaphase 1 affects the resulting gametes (50/50 for each of getting mother or father side)

2^n in any organism (n = haploid number)

the exchange of corresponding segments between 2 homologous chromosomes during the process of synapsis in prophase 1

sites of crossing over

formation of tetrads in P1; occurs when homologous chromosomes pair up during meiosis

the production of a gene combination different from what the original chromosome carried

result of chromatid with crossing over, different than parental genotype

chromatid without crossing over, same as parental genotype

an orderly display of magnified images of independent chromosomes

miscarriage / abortion

always death by miscarriage

3 copies of chromosome 21, shorter life span, round face, short stature, mental disability, most sterile, susceptible to disease

chromosome pair fails to separate --> aneuploidy (abnormal number of chromosomes in cell)

100% of gametes have abnormal chromosomes numbers

50% of gametes have abnormal chromosomes numbers

begins before born, only 1 matures per month = period, arrested mid-meiosis for decades leads to errors around 35+

Kleinfelter syndrome in males, small sterile testes, normal intelligence, breast enlargement

Turner syndrome in females, short, web of skin between neck and shoulders, sex organs don't fully mature so sterile

fragment lost, most serious, cri du chat syndrome

fragment joints to homologous chromosome

fragment reattaches to OG chromosome in reverse direction

fragment attached to nonhomologous chromosome

fragment just breaks off and attached, no exchange

2 nonhomologous chromosomes exchange segments (e.g. in down syndrome can result from only part of a 3rd chromosome 21)

chromosome reciprocal translocation in bone marrow, gene activated when chromosome 22 switches with a fragment of chromosome 9

one trait masks the effects of another trait

each gamete gets only one of the copies of each gene

9 dominant dominant; 3 dominant recessive; 3 recessive dominant; 1 recessive recessive

3 different characteristics involved, find all separately in punnett square and then use rule of multiplication

events occurring SIMULTANEOUSLY

EITHER event will occur

percentage of recombinants: recombinants over total offspring, all times 100

any gene located on a sex chromosome (usually X)

X-linked (males), malfunction of light sensitive cells in eyes

X-linked (males), bleed excessively, abnormal blood clots

X-linked (males), progressive weakening / loss of muscle tissue

two individuals with the same genotype have different phenotypes because they are in different environments, adapt to local environmental factors (e.g. temperature, nutrition, disease, physical activity; height and weight in humans, soil pH in flower color, seasonal fur color in arctic animals, sex determination in reptiles)

how much light is received during the day (arctic hare color change is linked to photoperiod)

males determine offspring

males determine offspring by not giving chromosome

females determine offspring

male fertiliztion determines offspring, unfertilized / haploid eggs are male, fertilized / diploid eggs are female

plants that produce both sperm and eggs (e.g. corn, pea plants)

animals that produce both sperm and eggs (e.g. garden snails, earthworms)

prevail in nature, not necessarily dominant; majority recessive in nature

recessive genetic disease, most common U.S. lethal disease, excess mucus in lungs cause breathing problems

recessive genetic disease, phenylalanine accumulation in blood, mental disability

recessive genetic disease, sickle red blood cells, tissue damage, pleiotropy and codominance

recessive genetic disease, lipid accumulation in brain cells, mental deficiency, blindness, childhood death

dominant genetic disease, nervous system degeneration, begins in middle age