Mitosis and Meiosis

studied byStudied by 36 people
5.0(1)
Get a hint
Hint

Roles of Cell Division in a cell

1 / 50

flashcard set

Earn XP

Description and Tags

51 Terms

1

Roles of Cell Division in a cell

Growth of an organism, repair of worn out cells, Asexual reproduction

New cards
2

Genome

All the DNA (usually packaged into chromosomes) in a cell

New cards
3

Chromosomes

an organized form of DNA (in the form of chromatin) that is packaged up in preperation for cell division

New cards
4

Somatic cells

non-reproductive cells w/ two sets of chromosomes (2n)

ex: human cells w/ 46 (23 in each set)

New cards
5

Gamete Cells

reproductive cells with one set of chromosomes (n)

ex: sperm and egg with 23

New cards
6

chromatin

the unraveled “messy” version of chromosomes, found in the cell almost always until it turns into chromosomes before cell division

New cards
7

chromatid

a copy of a chromosome joined to another sister chromatid along their lengths (via cohesions)

New cards
8

centromere

the narrow waist of the chromosome where two chromatids are closely attatched

New cards
9

Phases of the cell cycle

Interphase : Cell growth (G1), DNA replication (S), mitosis preperation (G2)

Mitosis (Cell division): Prophase, Prometaphase, metaphase, anaphase, telophase, cytokinisis

New cards
10

Characteristics of prophase

  • nucleolus dissapears

  • chromatin fibers begin to coil and condense into chromosomes (2 sister chromatids)

  • mitotic spindle begins to form

  • Centrosomes begin to move away from eachother

New cards
11

Characteristics of prometaphase

  • nuclear envelope breaks

  • microtubules, both kinetechore and not, from centrosome begin to move chromosomes or lengthen cell

  • chromosomes are more condensed

  • kinetochore formed at each sister chromatid

New cards
12

Characteristics of metaphase

  • centrosomes are now at cell poles

  • chromosomes align at metaphase plate after being pushed by microtubules

  • kinetochores of each chromatid are attached to the kinetochore-microtubule

New cards
13

Characteristics of anaphase

  • shortest stage

  • cohesion proteins keeping together sister chromatids are cleaved and they can part to become their own chromosomes

  • 2 new daughter chromosomes for each original move towards cell pole

  • kinetechore microtubules shorten to pull them

  • nonkinetochore microtubules lengthen the cell by overlapping and pushing against each other

New cards
14

Characteristics of telophase

  • two daughter nuceli reform

  • nuclear envelopes reform from the fragments

  • nucleoli reform

  • chromosomes begin to uncondense

  • spindle microtubules dissapear

New cards
15

cytokinesis

  • two daughter cells form

  • cleavege furrow formed in animal cellls

  • new cell wall formed in animal cells

New cards
16

mitotic spindle

a structure made of microtubules that controls chromosome movement during mitosis. consists of centrosome pairs, spindle microtubules, and asters (array of short microtubules extending from censtrosome)

New cards
17

kinetochore

protein complex associated w centromeres and attatched to each sister chromatin. attatches to kinetochore microtubules

New cards
18

metaphase plate

imaginary line down the middle of the cell where chromosomes align during metaphase

New cards
19

kinetechore microtubules

extend from the centrosomes and attactch to kinetichores on each chromatid pair. pulls them to the middle and eventually apart

New cards
20

non kinetochore microtubules

overlap and push up against eachother to elongate the cell

New cards
21

binary fission

how prokaryotes such as bacteria duplicate. chromosomes rpelicate at origin of replication, move apart, and the plasma membrane pinches in two

New cards
22

cell cycle control system

internal and external controls that regulate the cell cycle, characterized by checkpoints

New cards
23

cyclins

a regulatory protein involved in cell cycle control named for cyclically fluctuating conc. in cell

New cards
24

cyclin dependent kinases (cdks)

must be attached to cyclin to be active, activity rises and falls along w cyclin conc.

New cards
25

MPF(Maturating promoting factor)

a cyclin cdk complex that triggers a cells passage past the g2 phase into the mitotic phase

New cards
26

g1 checkpoint

at this point, if it recieves a check the cell usually goes through all other phases and divides normally. if it doesnt, the cell will switch to the nondividing g0 phase

New cards
27

growth factors

factors released by other cells that stimulate others to divide

New cards
28

density dependent inhibition

cells stop dividing once they reach a certain density

New cards
29

anchorage dependence

to divide, a cell must be attatched to a substratum

New cards
30

benign tumors

cancerous cells remain at the original site and do not spread

New cards
31

malignant tumors

cancerous cells invade surrounding tissue and undergo metastasis

New cards
32

metastasis

the spread of cancer cells to other parts of the body

New cards
33

Heredity

The transmission of traits from one generation to the next

New cards
34

Gene

are the units of heredity and are made up of segments of DNA

New cards
35

locus

A gene’s specific position along a chromosome

New cards
36

asexual reproduction

a single individual passes all of its genes to its offspring without the fusion of gametes & makes clones (exact copies)

New cards
37

sexual reproduction

2 parents give rise to offspring that have unique combinations of genes inherited from the 2 parents

New cards
38

life cycle

the generation-to-generation sequence of stages in the reproductive history of an organism

New cards
39

karyotype

an ordered display of the pairs of chromosomes from a cell (homologous pairs)

New cards
40

homologs/homologous chromosomes

the chromosomes that make up a homologous pair

New cards
41

sex chromosomes

determine the sex of the individual (X and Y, XX = girl XY = boy)

New cards
42

diploid vs haploid chromosome number

diploid = 2n (ex: 46), haploid = n (ex: 23)

New cards
43

fertilization

the union of gametes (the sperm and the egg)

New cards
44

zygote

The fertilized egg with one set of chromosomes from each parent

New cards
45

meiosis 1

homologous chromosomes are seperated into two haploid cell each w 23 chromosomes in humans (meiosis isnt done yet, because each chromosome still has a pair of sister chromatids)

New cards
46

meiosis 2

the haploid cells from meiosis 1 each seperate again into 2 more haploid cells each w 23 chromosomes in humans (no more pairs of sister chromatids, just chromatin now)

New cards
47

events/traits unique to meiosis

in both meiosis 1 and 2, the same steps as mitosis happen except:

  1. Synapsis and crossing over in prophase I: Homologous chromosomes physically connect and exchange genetic information (switching it up to give variety)

  2. Alignment of homologous pairs at the metaphase plate (instead of seperate chromosomes, they align in pairs)

  3. Separation of homologs during anaphase I (instead of sister chromatid sepertaion, just the homologs seperate for now)

  4. Starting meiosis 2 with haploid cells instead of diploid ones (half the num of chromosomes as usual)

New cards
48

mitosis vs meiosis (productwise)

mitosis produces 2 diploid cells that are identical clones. meiosis produces 4 haploid cells that all vary due to chromosomes being switched around between father and mother genes

New cards
49

recombinant chromosomes

chromosomes with combined DNA from both parents. a product of chromosomes crossing over during meiosis.

New cards
50

random fertilization

it adds to genetic variation because any sperm can fuse with any ovum (unfertilized egg)

New cards
51
New cards

Explore top notes

note Note
studied byStudied by 6 people
... ago
5.0(1)
note Note
studied byStudied by 3 people
... ago
5.0(1)
note Note
studied byStudied by 66 people
... ago
4.0(1)
note Note
studied byStudied by 85 people
... ago
5.0(1)
note Note
studied byStudied by 31 people
... ago
5.0(1)
note Note
studied byStudied by 44 people
... ago
5.0(1)
note Note
studied byStudied by 46 people
... ago
5.0(1)
note Note
studied byStudied by 23481 people
... ago
4.8(187)

Explore top flashcards

flashcards Flashcard (44)
studied byStudied by 6 people
... ago
5.0(1)
flashcards Flashcard (20)
studied byStudied by 10 people
... ago
4.0(1)
flashcards Flashcard (23)
studied byStudied by 18 people
... ago
5.0(1)
flashcards Flashcard (60)
studied byStudied by 15 people
... ago
5.0(1)
flashcards Flashcard (35)
studied byStudied by 7 people
... ago
5.0(1)
flashcards Flashcard (182)
studied byStudied by 3 people
... ago
5.0(1)
flashcards Flashcard (22)
studied byStudied by 1 person
... ago
5.0(1)
flashcards Flashcard (20)
studied byStudied by 32 people
... ago
5.0(1)
robot