Mitosis Meosis Cell Division

Front 1

What happens to cell in 1st stage of mitosis

Back 1

Interphase

(technically not part of mitosis, but it is included in the cell cycle)

Cell is in a resting phase, performing cell functions

DNA replicates (copies)

Organelles double in number, to prepare for division

Front 2

Prophase

Spindle forms

Centrioles move to opposite poles

Chromosomes become visible

Back 2

What stage is this, what happens?

Front 3

Metaphase

Chromosomes line up along the equator

Back 3

What stage of mitios is this? what happens

Front 4

Anaphase

Centromeres divide

Chromatids separate and move to opposite poles

Back 4

What stage of mitios is this? what happens

Front 5

Nuclear membrane forms around each group of chromosomes

Chromosomes unwind

Cytokinesis begins

Back 5

What stage of mitosis is this what happens?

Front 6

Interphase is the same in both mitosis and meiosis, but in meiosis, it is followed by two cell divisions. These two division processes are referred to as Meiosis I and Meiosis II, and result in a total of four daughter cells, each with a 1n chromosome number

Back 6

what stage of meoisis is this what's happening?

Front 7

In prophase I, notice the difference in how the homologous chromosomes behave. They come together and match up (synapsis) in pairs (tetrads or bivalents). In human females, this stage happens prior to birth when the ovaries are forming, and then stops. A baby girl is born with all the precursor egg cells she will ever have in a sort-of "suspended animation" until puberty (hence abdominal x-rays are dangerous for any young to middle-aged human female, not just pregnant women, and hence there is a greater likelihood that a 40-yr-old mother will have a baby with Down Syndrome – due to incorrect meiosis — than a 20-yr-old mother

Back 7

what stage of meoisis is this what's happening?

Front 8

metaphase I-Bivalents, each composed of two chromosomes (four chromatids) align at the metaphase plate. The orientation is random, with either parental homologue on a side. This means that there is a 50-50 chance for the daughter cells to get either the mother's or father's homologue for each chromosome

Back 8

what stage of meoisis is this what's happening?

Front 9

Chiasmata separate. Chromosomes, each with two chromatids, move to separate poles. Each of the daughter cells is now haploid (23 chromosomes), but each chromosome has two chromatids

Back 9

what stage of meoisis is this what's happening?

Front 10

Telophase I
Nuclear envelopes may reform, or the cell may quickly start meiosis 2.

Back 10

What stage of meosis is this?

Front 11

What happens in meosisII?

Back 11

Meiosis 2 is similar to mitosis. However, there is no "S" phase. The chromatids of each chromosome are no longer identical because of recombination. Meiosis II separates the chromatids producing two daughter cells each with 23 chromosomes (haploid), and each chromosome has only one chromatid.

Front 12

anaphase

Back 12

a phase of mitosis and meiosis in which the chromosomes
separate (150)

Front 13

asexual reproduction

Back 13

the production of offspring that does not involve the
union of gametes (156)

Front 14

autosome

Back 14

a chromosome that is not a sex chromosome (146

Front 15

binary fission

Back 15

an asexual cell division of prokaryotes that produces identical
offspring (148)

Front 16

cell cycle

Back 16

the events of cell division; includes interphase, mitosis, and
cytokinesis (149)
cytokinesis the division of the cytoplasm of one cell into two new cells (149)

Front 17

centriole

Back 17

a structure that appears during mitosis in animal cells (150)
centromere a region of the chromosome where the two sister chromatids are
held together and which is the site of attachment of the chromosome to the
spindle fibers during mitosis (146

Front 18

cell plate

Back 18

a membrane that divides newly forming plant cells following
mitosis (151)

Front 19

chromatid

Back 19

one of two identical parts of a chromosome (146)

Front 20

centrosome

Back 20

a dark body containing a centriole in animal cells but not in plant
cells; spindle fibers radiate from the centrosome in preparation for mitosis (150)

Front 21

cleavage furrow

Back 21

the area of the cell membrane that pinches in and eventually
separates the dividing cell (151)

Front 22

crossing-over

Back 22

the exchange of genes by reciprocal segments of homologous
chromosomes during meiosis (153)

Front 23

diploid

Back 23

a cell that contains both chromosomes of a homologous pair (147)

Front 24

gamete

Back 24

a reproductive cell (153)

Front 25

genetic recombination

Back 25

the new mixture of genetic material after crossing-over
has taken place (154)

Front 26

G0 phase

Back 26

a phase of the cell cycle in which the cell is not dividing and its DNA
is not replicating (149)

Front 27

G1 phase

Back 27

the first period of interphase, in which the cell doubles in size (149)

Front 28

G2 phase

Back 28

the final period of interphase, in which the cell undergoes rapid
growth and prepares for mitosis (149)

Front 29

haploid

Back 29

having only one chromosome of each homologous pair (147)

Front 30

histone

Back 30

a protein molecule that DNA wraps around during chromosome
formation (145)

Front 31

homologous chromosome

Back 31

one of a pair of morphologically similar
chromosomes (146)

Front 32

independent assortment

Back 32

during meiosis, the random distribution of genes
from different chromosomes to the gametes (154)

Front 33

interphase

Back 33

a period of cell growth and development that precedes eukaryotic
cell nuclear division (149

Front 34

karyotype

Back 34

a picture of an individual’s chromosomes (147)

Front 35

kinetochore fiber

Back 35

a spindle fiber that extends from the centrosome at one pole
of the cell to a chromatid during mitosis (150

Front 36

kinetochore

Back 36

a disk-shaped protein found in the centromere region of a
chromosome that attaches the chromosomes to the mitotic spindle (150)

Front 37

meiosis

Back 37

the process of nuclear division that reduces the number of
chromosomes in a cell by half (148)

Front 38

metaphase

Back 38

the second phase of mitosis, during which all the chromosomes
move to the cell’s equator (150)

Front 39

mitosis

Back 39

eukaryotic nuclear division (148)

Front 40

mitotic spindle

Back 40

the array of spindle fibers that serve to divide the chromatids
during nuclear division (150)

Front 41

M phase mitosis

Back 41

the phase of cell division in which the nucleus divides (148)

Front 42

polar body

Back 42

one of two small cells produced and discarded during each of the
two meiotic divisions that yield the haploid egg (156)

Front 43

polar fiber

Back 43

fibers that extend across a dividing cell from centrosome to
centrosome (150)

Front 44

oogenesis

Back 44

the production of mature egg cells (155)

Front 45

prophase

Back 45

the first stage of mitosis and meiosis, characterized by condensation
of chromosomes (150)

Front 46

sex chromosome

Back 46

a chromosome that determines sex (146)

Front 47

sexual reproduction

Back 47

the production of offspring from the combination of
genetic material from two parent organisms (156)

Front 48

spermatid

Back 48

in meiosis, a haploid cell that develops into a mature sperm
cell (156)

Front 49

spermatogenesis

Back 49

the production of sperm cells (155)

Front 50

S phase

Back 50

the second period of interphase during which replication of DNA
occurs (149)

Front 51

spindle fiber

Back 51

one of the microtubules that extend across a dividing eukaryotic
cell; assists in the movement of chromosomes (150)

Front 52

synapsis

Back 52

the pairing of homologous chromosomes during meiosis (153)

Front 53

telophase

Back 53

the final stage of mitosis during which a nuclear membrane forms
around each set of new chromosomes (151)

Front 54

tetrad

Back 54

a group of two homologous chromosomes during meiosis (153)