The Cell Cycle, Mitosis, and Meiosis - Biology

heyyyyyy guys so this is a review for bio for the cell cycle, mitosis and meiosis (meiosis 1 and meiosis 2) :)))) enjoy!!!! :) happy testing!! I wish you all the best of luck! Good luck!

cell division

creates new cells(from 1 to 2 new cells)

asexual reproduction

creating genetically identical offspring

what are some advantages of asexual reproduction?

quick, easier, no pregnancy, less time, clone

sexual reproduction

creating genetically diverse offspring(only main advantage)

binary fission

a type of asexual reproduction

used by many bacteria

creates 2 daughter cells from 1 parent

chromatin

loosely wound DNA

chromosome

tightly wound DNA

what is the DNA in a chromosome wrapped around

histone proteins

sister chromatids

duplicated chromosomes held together at centromere (X)

interphase

G1, S, G2 except Mitosis

What is the order of the cell cycle?

G1, S, G2, M

mitosis

nuclear division that maintains chromosome number

how many chromosomes per human

46 chromosomes

what are the 4 phases of mitosis

prophase

metaphase

anaphase

telophase

what happens in prophase

nucleolus disappears

chromatin condense into chromosomes

separation of centrosomes(centrioles)

formation of spindle fibers

what happens in prometaphase

nuclear envelope disassembles

spindle fibers (microtubules) attach to chromosomes

what happens in metaphase

chromosomes align on the metaphase plane (middle)

what happens in anaphase

chromatids separate towards opposite poles

what happens in telophase

new nuclear envelope forms

chromosomes unfold back into chromatin

nucleoli reappear

what is cytokinesis

occurs after mitosis

daughter cells divide

2 new cells form from 1 original cell

how do plant cells do cell division

form a new cell wall from cell plate

how is a cell plate formed

vesicles line up

how do animal cells do cell division

they pinch and turn into 2 cells from 1 cell

how do animal cells pinch

cleavage furrow with is a contracting ring making 2 new cells from 1

what is cancer

uncontrolled cell division

what is a mass of cells called

tumor

what do most cells need to divide

growth factor (proteins and signals tell them to divide)

why are checkpoints important

to make sure cells are good and correct so that there are no issues, no bad cells replicating

what happens if a cell fails a checkpoint

G0 —> try to fix cell—> can’t fix them destroy cell

apoptosis

programmed cell death

why is apoptosis good

it prevents cancer and only affects the 1 cell (not like all cells getting damaged)

necrosis

cell dies due to trauma, etc., not programmed, causes damage to other cells

what do cancer cells do at checkpoints

ignore them

what are the stages of cancer and what do they mean

1- small mass

2- spread in the same area

3+4- spread to other parts of the body

what is it called when cells spread to other parts of the body

metastasize

ploidy

number of sets of chromosomes

haploid

1 set of chromosomes

diploid

2 sets of chromosomes

humans are diploid or haploid

diploid we have 46 chromosomes in 2 sets 1 set from mom and 1 from dad (23 from each)

what is the 23 set of our chromosomes

XY

for every single type of chromosome we have we have how many sets

2

mitosis drawing

Meiosis definition

nuclear division that halves chromosome number

What is the result of meiosis 1 and meiosis 2

meiosis 1 - starts from 1 diploid cell and results in 2 haploid cells

meiosis 2 - starts from 2 haploid cells and results in 4 diploid cells

haploid shorthand

1n

diploid shorthand

2n

what kind of cells come from meiosis

gametes (sperm and eggs)

what kind of cells are the first cells in meiosis

germ cells

what are germ cells

they are in ovaries and testes and are supposed to make sperm and egg

why don't germ cells just immediately split into four cells

we would run out of germ cells

What do the cells do instead to preserve a germ cell

they perform mitosis

what are the 3 ways meiosis increases genetic diversity

crossing over, independent assortment, random fertilization

what is independent assortment

how they line up all ways are equally likely because it is random

when does independent assortment occur

metaphase 1

what does the diploid shorthand (2^n) mean/determine

n = sets of chromosomes (for example humans have 23)

so 2^n helps determine the number of different combinations or orders of chromosomes

(humans 2²3 = 8,000,000)

what is crossing over/ genetic recombination

when the 2 chromosomes cross over each other and swap some genes

when does crossing over occur

during Prophase 1

when crossing over what has to match for them to be able to cross over

their number (a 1 to a 1, 2 to a 2, etc)

the area that swaps on a chromosome is called

chiasma

what is random fertalization

sperm and egg are random, random sperm fertilizes random egg

what is nondisjunction

when chromosomes don’t separate correctly

how can nondisjunction occur in meiosis 1

this can happen because of the failure of a pair of homologous chromosomes to separate during meiosis 1 (an entire tetrad moves to one side)

how can nondisjunction occur in meiosis 2

the failure of sister chromatids to separate during meiosis 2

what is affected if the mistake occurs in meiosis 1

it will affect all four gametes (sperm or egg)

what is affected if the mistake occurs in meiosis 2

only 2 gametes will be affected

what is a karyotype

a picture of someones chromosomes

what are a males sex chromosomes

XY

what are a females sex chromosomes

XX

whta is it called when there is an extra copy of chromosomes 21

down syndrome (trisomy 21)

what is the biggest risk factor for having a child with trisomy 21

a woman’s age

why is a woman’s age a big risk factor

nondisjunction increases as you age

what is the effect of an abnormal number of sex chromosomes

not usually any effects

doesn’t usually affect survival (could)

health issues sometimes come with what chromosomes

XXY

usually normal with what chromosomes

XXX

mutation

a change in DNA

gametes are produced by

meiosis

what is the first cell of a new human called and what is the process that the cell does to create more cells to become multicelluar?

zygote and the process is mitosis

difference between mitosis and meiosis

mitosis creates all the hair, skin, nails, etc.

meiosis creates gametes (from sperm and egg cells), crossing over occurs

In humans, the haploid number of chromosomes is 23. Independent assortment has the possibility of producing __________ different gametes.

2²³

karyotype

order of meiosis I

prophase I

metaphase I

anaphase I

telophase I

cytokinesis

order of meiosis II

prophase II

metaphase II

anaphase II

telophase II

cytokinesis

difference between benign and malignant tumors

malignant tumors metastasize, spread

benign tumors do not spread

difference between meiosis 1 and meiosis 2

meiosis 1 - homologous pairs separate (happens in anaphase 1)

meiosis 2 - sister chromatids separate (happens in anaphase 2)

What is to be on the test

multiple choice, short answer, and drawing (prolly drawing cell cycle??, mitosis, meiosis 1, meiosis 2??)