Meiosis

division of a nucleus

division of prokaryotic cells

they are two processes that produce daughter cells identical to the parent cell

produces daughter cells with half of the DNA of the parent cell

cells produced by meiosis

meiosis goes through cell div twice while mitosis does only once; in meiosis you have 4 daughter cells while in mitosis u only have two; mitosis takes places in organs and tissues while meisosis takes place in reproductive organs; number of chromosomes in daughter cells in mitosiss is 2n and in meiosis is n; homologous chromosomes divide in meisis but not in mitosis

the failure of homologuous chromosomes to separate in either meiosis i or in meiosis ii

different genes assort (passed into gameter) independentl ybceuse they are located on diferent chomromsomes which align randomly at the metaphase plate during meisois i

when homologous chromosomes exchange segments of dna at cross over sites called chiasmata

when dna crosses over

interphase

prophase 1

four sister chromatids

4/4

1/4

having homologous pairs/two copies of each chromosome

having one copy of each chromosome

prosphase 1, metaphase 1, anaphase 1, telophase 1 and cytokinesis

prophase 2, metaphase 2, anaphase 2, telophase 2 and cytokinesis

reproductive organs

2

4

Yes

yes

yes

in prophase 1, replicated homolous chromosome join to form a structure called a tetrad. tetra means 4, 2 replicated chromosomes in a total of 4 sister chromatids

series of 4 sister chromatids (2 for each chromosome in the homologous pair) that overlaps at areas

when homologous chromsosmes pair up during propahse 1

recombination of alleles from one individual

it maxes the variety in gametes produced, which results in variety in offpring

3 chromosome 21

if one parent has a gamete that has experienced nondisjunction, it contains two copies of chromosome 21 instead of 1. when joined with the other gamete this is total of 3 chromosome 21

he conducted experiments with pea plants to provide evidence for inheritance of dominat and recessive traits

he provided a helpful tool for evaluating probablility of this inheritance ith the punnett square

alleles

on homologous chromosomes

uppercase

lowercase

homozygous

heterozygous

homozygous

genotypes are the genes or combinations of alleles that an organism has. the phenotype is the physical trait or observable expression of the trait that we see as the result of the genotypes

1

when haploid gametes combine, the offspring will have a diploid number of chromosomes with one allele from each parent

lowercase letters typically represent recessive traits.

if no traits are recessive to each other, it make more sense for both to be represented wtih uppercase letters as both are dominant.

AB+ , A+, B+, O+, AB-, A-, B-, O-

I(A), I(B), i, Rh+,Rh-

i is recessive to I(A) and I(B) -- in fact, it is the only recessive allele for blood type because it does not code for any antigens

Phenotype

both A and B antigens are present on RBCs

genotype

ii

I(A)I(A) or I(A)i

I(B)I(B) or I(B)i

I(A)I(B)

X

male

female

affected male

carrier female

superscript next to an uppercase X (X(H))

male because they have only one copy of that gene (one X) only one allele to determine that phenotype

traits controlled by multiple genes

more

an extra simplified biologial family tree

to track one trait over many gen

the trait is recessive

dominant

sex linked recessive trait

genotypes that are different from parents

when gene is further apart on chromosome

crossing with a homozygous recessive for both traits

a group of genes whose loci are on the same chromosome and don't not independently assort

genes are on different chromosomes, iherited independently, and should follow the 9:3:3:1 ratio

a test to find differences observed are due to chance or linked

x^2= sigma [(O-E)^2/(E)]

O is observed value, sigma = sum, e = expected (or predicted) value

punnet swaures

1) create hypothesis
2) calc the chi swaure
3) look up critival value fro mtable
4) compare act results with predicted

number of outcomes minus one

it is a point on the graph where its labelled 0.05. and there's a number below it

reject ur null hypothesis

accept ur null hypothesis

theorizing that there is no sig difference between observed and expected results

in brain cells

multiple alleles