AP Bio Unit 5: Heredity

Meosis, Genetics

Meosis Steps

Meosis 1 and Maeosis 2

Meosis Steps

Meosis 1 and Maeosis 2

Prophase I - Chromatin Condenses, sister chromatids and homologous pairs align and crossing over takes place

Metaphase I: Homologous Chromosomes align on the metaphase plate and Independent Assortment occurs

Anaphase I: Separation of Homologous.

Prophase II Chromatids alsign

MetaphaseI sister chromatids align on the metaphase plate

Anaphase II sister chromatids serpeate

Telophase II - leads to individual haploid gametes

What is Crossing over?

The Homologous Pairs cross genes and switch genes → recombinants

occurs during prophase 1

increases genetic diversity

occurs more when father from the centromere

Homologous Pairs vs Sister Cromatids

Homologous Pairs is same type of Chromosome but one from each parent - separated in meosis one

Sister Cromatids are just duplicate chromosomes - separated in meosis 2

Independent Assortment

another way for genetic variety

one chromosome goes with a nother etc

number of different arrangments can be calculated by 2^x

x=# of haploid chromosomes

What are Gametes

gametes have half a set of chromosomes

Products of Meosis and (n) values over tie and steps

2n → (2) n → Gametogenesis (4) n

Nondisjucntion

the chromosomes do not serperate propery in anaphase

Mitosis

cells will divide and be exactly the same as parent

for grwoth and repair

how do prokayotes reproduce

what about protists

what about yeast and some mutli cellular trees

binary fission

idk

budding

Complete Dominance

the homozygous dominant and heterozygous look the same

the dominant protein can mask the ressesive one

Co dominance

heterozygous is both dominant traits in organisms

will show the heterzygous as both colors

Incomplete dominance

blended “color”

Monohybrid Cross Ratios

Complete

Incomplete

3:1

1:2:1

Test Cross

Cross and unknown with a homozygous ressesive

Dihybrid Ratios

Compelte and Incomplete

9:3:3:1

6:3:3:2:1:1

Multiplication Crosses Rules

If there are multiple traits, do a cross for each

multiply the probabilities to find it

Autosomal Inhereitance

Sex Linked

Maternal

Linked Genes

Auto: non sex

Sex Linked: on the sex chromosome

Maternal: mitocondrial or chloroplast - mother → all children

Linked: same chromosome - the offspring would mostly be the phenotypes of the parents

different system for sex

ZW-ZZ

XX - XY

Differnt Meosis Genetic Variation

crossing over,

indepdent assortmnet

random fertilization

Recomibanation Frequency

• means crossing over frequency

(recombinants)/ Total

Genetic Disorders that might show up

• Sickle Cell

• Tay Sachs

• hunginton Diseases

Chromosomal disease

• down syndrome (trisonomy 21)

• Klinefelter Syndrome XXY

• Turners Syndrme XO

Karotypes

show chromosomal images

can show chomrosomal diseases

Phenotype Plasticiy and Envirometn

• the enviroment could influence the gene expression

• Diet can affect phenotypes

• acidicy of the soil for plants

How does a child have the genes of both parents and grandparents

crossing over allows for genes to be mixed and allows DNA from both parents and grandpaernts

what is a tetrad

a homologous duplicated pair

what does meosis create

haploid gametes

what is an allele

how much is passed from each parent

different versions of genes

gametes only pass one of their 2 alleles

male sexlinked

only have one allele

crossing over and nondisjunction

crossing over is needed for proper serpation

kinetetochores

are like ther handles for the microtubles that connect to the spindles, nessecary for proper seperation of chromatids

Polygenic traits

Traits controlled by more than one gene

Centrosome

Microtuble organizers and where spindles attach with kinetochores

Basal bodies

Where the microtuboes for cilla, flagella, attach