Cell Cycle and Genetics

mitosis

nuclear division

cytokenesis

cytoplasm division

somatic cells

body cells

gametes

sex cells

Interphase

takes up 90% of the cell cycle, is the longest part, and is the growth stage

M phase

division stage of cell cycle, includes nuclear and cytoplasm division

G1 phase

First step in interphase; cell growth and prepares for dna replicatation

G0 Phase

when cells no longer divide

S Phase

DNA replication; important in order to have the correct number of chomosomes

G2 Phase

Last part of interphase; last cell growth and prepares for division

Prophase

1st step of mitosis

What stage of mitosis does the chromatin coil tightly and becomes visible as a sister chromatid

prophase

At what stage of mitosis does the nuclear membrane disappear and centrioles move towards the poles while spindle fibers are forming

prophase

Metaphase

2nd phase of mitosis

When do the spindle fibers attach to the centromere

metaphase

When do the sister chromatid line up in the middle

metaphase

Anaphase

3rd phase of mitosis

When are sister chromatid separated

anaphase

what pulls the sister chromatid apart

spindle fibers attached to the centrioles at the poles

telophase

final phase of mitosis

When is separation of the chromosomes complete

telophase

when do the chromosomes uncoil

telophase

When does the nuclear membrane form again

telophase

cleavage furrow

forms in animal cells during cytokinesis

cell plate

forms in plants during cytokinesis

External signals

outside of the cell, proteins called growth factors can signal a cell to divide

Internal checkpoints

checkpoints that makes sure cells go under proper division

G1 checkpoint

check that the cell has reached the right size

G2 checkpoint

checks to make sure there is the correct number of chromosomes

M checkpoint

checks that all sister chromosomes are attached to the spindle in metaphase

apoptosis

cell death

mass of cells that is growing out of control

tumor

cancer

abnormal division and invading healthy tissues

carcinogen

damages dna and causes mutations and cancer

metastasis

the spread of cancer

meiosis

occurs in reproductive cells

Which cells are diploid and 46 total chromosomes

somatic

which cells are haploid (n) and 23 total chromosomes

gametes

what kind of cells are gametes

sperm and eggs

homologous chromosome

two chromosomes similar in size and shape that make up each pair in human somatic cells

when do tetrads form

prophase 1

when does crossing over during meiosis occur

prophase 1

when do tetrads align in the middle

metaphase

When does meiosis 2 occur

immediately after cytokinesis

how many cells are produced during mitosis

two diploid daughter cells

how many cells are produced during meiosis

four haploid daughter cells that are genetically diverse

allles

same genes

asexual reproduction

takes 1 parent and the offspring is identical

binary fission (asexual)

many single-celled organisms just divide in half

budding (asexual)

small mass of cells detaches from parent and grows into a separate organisms

vegetative propagation (asexual)

when plant offerings are produced via stems and roots

Fragmentation (asexual)

forming new organisms via a broken piece of the original organism

sexual reproduction

required two organisms and offspring are genetically different

fertilization

the union of a sperm and egg

advantages of sexual production

offspring are genetically different which may help the organism adapt and survive a changing environment

advantages of asexual reproduction

produces a large number of offspring and quickly and requires only one parent

asexual disadvantages

offspring are genetically identical to parent which may limit their ability to survive

sexual disadvantages

produces a lower amount of offspring more slowly and requires two parents

traits

distinct heritable features or characters with different varients

true-breeding

when a plant self pollinates

p gen

the starting generation

f1 gen

offspring of original parents

f2 gen

offspring of offspring

alleles

alternate versions of genes

law of segregation

two alleles for a trait separate and segregate during gamete production and end up in different gametes

two identical alleles for a character

homozygous (rr)

two different alleles for a character

heterozygous (Rr)

Phenotype

what the organism looks like

genotype

genetic make up

monohybrid

1 trait being crossed

dihybrid

2 traits being crossed

Codominance

tow alles affect the phenotype in separate distinguishable ways (roan and spots)

Incomplete dominace

blend of of alleles

multiple alleles

more than two allelic forms (blood type)

pleiotropic

affecting more than one phenotypic character/ affects multiple phenotypes

epistasis

when one gene turns off another

polygenic inheritance

when multiple genes have an influence on phenotype

Cystic fibrosis

autosomal recessive

tay-sachs disease

autosomal recessice

sickle-cell disease

autosomal recessive

huntington’s disease

autosomal dominant

tetrads

instead of sister chromosomes, tetrads for during mitosis and are paired homologous chromosomes