Mitosis and Meiosis

What is reproduction

process of making new cells or organisms

what must parents pass to daughter cells

dna and cell materials

what is chromosome

dna wrapped around proteins

why do chromosomes duplicate

to prepare for cell division

what is chromatid

one half of a duplicated chromosome

what are sister chromatids

two identical copies of a chromosome

what is the cell cycle

process of cell growth and division

what is interphase

stage when the cell grows and copies DNA

3 phases of interphase

G1, S, G2

when is dna copied

S phase

what is chromosome number

total number of chromosomes in a cell

what does diploid mean

2 copies of each chromosome

what does haploid mean

1 copy of each chromosome

are body cells diploid or haploid

diploid

are gametes diploid or haploid

haploid

how many chromosomes do a human body have

46

how many chromosome pairs do human have after mitosis

23

what are the s3x chromosomes

x and y

what is mitosis

division of nucleus to make two identical cells

4 stages of mitosis

prophase, metaphase, anaphase, telophase

what phase is this

prophase

what phase is this

metaphase

what phase is this

anaphase

what phase is this

telophase

results of mitosis

2 new nuclei form

what is not a function of mitosis

hormone

what is cytokinesis

division of cytoplasm

how do animals cells divide during cytokinesis

clevage

how do plant cells divide during cytokinesis

cell plant formation

what happen when cell cycle checkpoints fail

cancer can develop

what is oncogene

a gene that causes cancer

what is proto-oncogene

gene that promotes cell division

tumor supressor gene

gene that slows or stops cell division

what is meiosis

process that makes haploid gametes

why is meiosis necessary

to cut chromosomes number in half

how many divisions occur in meiosis

2

how many cells are by meiosis?

4 haploid cells

what phase is this

prophase 1

what happens in prophase 1

Homologous chromosomes pair up and crossing over occurs

What happens in Metaphase I?

Homologous pairs line up in the middle of the cell.

what phase is this

metaphase 1

results of Meiosis ll

four haploid cells with unduplicated chromosomes

why is meiosis important besides reducing chromosomes number

it creates genetic variations

two sources of variation in meiosis

crossing over and independent assortment

what is crossing over

homologous chromosomes exchange dna

when does crossing over occur

prophase 1

why is crossing over important

it creates new gene combinations

What is independent assortment?

chromosomes separate randomly into gametes

Why is independent assortment important?

it increases genetic variation

What is non-disjunction?

failure of chromosomes to separate correctly

What can non-disjunction cause?

extra or missing chromosomes

What condition is commonly caused by non-disjunction?

down syndrome

What is fertilization?

fusion of male and female gametes

What is a zygote?

a diploid cell formed after fertilization

What type of cells does mitosis occur in?

somatic (body) cells

What type of cells does meiosis occur in?

germ cells

How many cells does mitosis produce?

2

How many cells does meiosis produce?

4

Are mitosis daughter cells identical or different?

identical

Are meiosis daughter cells identical or different?

different

What is the function of mitosis?

growth and repair

What is the function of meiosis?

sexual reproduction