cell division

Question 1

what is cell division?

Answer 1

one parent cell divides to make two daughter cells with the same genetic material/DNA

Question 2

before cell division what must happen?

Answer 2

parent must copy all of its DNA

Question 3

FACT: each daughter cell gets 1 copy of genetic information

Question 4

why do cells divide?

Answer 4

for reproduction

Question 5

what is asexual reproduction?

Answer 5

organisms divide and make exact copies of themselves

Question 6

what is the problem with asexual reproduction?

Answer 6

no genetic diversity

Question 7

what kind of organisms reproduce asexually?

Answer 7

organisms, bacteria, protists

Question 8

what is sexual reproduction?

Answer 8

fusion of 2 sex cells AND has genetic diversity

Question 9

what kind of organisms reproduce sexually?

Answer 9

plants, animals

Question 10

what is the problem with sexual reproduction?

Answer 10

lots of resources and finding a partner

Question 11

DNA is usually in the form of chromatin, what is chromatin?

Answer 11

long string like fibers

Question 12

once cells get ready to divide, what happens to DNA?

Answer 12

it coils up into compact structures

Question 13

what are those compact structures that DNA coils up into called?

Answer 13

chromosomes

Question 14

FACT: chromosomes are single DNA molecules coiled up

Question 15

chromosomes have two identical copies called what?

Answer 15

sister chromatids

Question 16

FACT: sister chromatids are exact copies of eachother

Question 17

the sister chromatids are held together at the center of what?

Answer 17

the centromere

Question 18

what do sex chromosomes do?

Answer 18

determine the sex of a chromosome

Question 19

FACT: XX- female XY-male

Question 20

what are autosomes?

Answer 20

nonsex chromosomes

Question 21

1 organism has how many copies of each autosome?

Answer 21

2- one from each parent

Question 22

the two copies of each autosome are called what?

Answer 22

homologous chromosomes

Question 23

FACT: homologous chromosomes are the same size and shape and carry genes for the same traits

Question 24

how many chromosomes do humans have?

Answer 24

46 in body cells, 2 sex cells

Question 25

what are diploid cells?

Answer 25

two sets of chromosomes -> 2n; called somatic cells (body cells)

Question 26

what are haploid cells?

Answer 26

one set of chromosomes -> 1n, called germ or gamete cells (sex cells)

Question 27

FACT: each diploid cell has 46 chromosomes, each haploid cell has 23 chromosomes

Question 28

what are prokaryotes?

Answer 28

division of binary fission- each daughter cell has an exact copy of the parent

Question 29

what are the two divisions of eukaryotes?

Answer 29

mitosis- division of diploid/ somatic/body cells - daughter cells genetically identical to parent meiosis- division of haploid/gamete/sex cells -daughter cells genetically different to parent

Question 30

what is the G1 phase, S phase and G2 phase?

Answer 30

G1 phase- cell growth, after cell division daughter cell is much smaller than parent S phase- synthesis phase, DNA copies itself G2 phase- cell growth pt. 2, prep for cell division

Question 31

what comes after these 3 phases?

Answer 31

Cell division -> PMAT (mitosis) AND cytokinesis

Question 32

what is cytokinesis?

Answer 32

division of cytoplasm

Question 33

what is the G0 phase?

Answer 33

dormant phase- no division takes place

Question 34

what is prophase?

Answer 34

spindle fibers begin to form, DNA condenses into chromosomes (sister chromatids together), nuclear envelope disappears

Question 35

what is metaphase?

Answer 35

chromosomes line up in the middle of the cell, spindle fibers grow and bind into centromeres

Question 36

what is anaphase?

Answer 36

centromere breaks and each chromatid is pulled by spindle fibers to each side of the cell

Question 37

what is telophase?

Answer 37

spindle fibers disassemble, DNA returns to chromatin form

Question 38

what are animal cells?

Answer 38

cell membrane pinches inward between the cells creating a cleavage furrow, 2 new cells

Question 39

what are plant cells?

Answer 39

vesicles fuse at the midline creating a membrane bound cell wall called a cell phase

Question 40

what are plant cells?

Answer 40

vesicles fuse at the midline creating a membrane bound cell wall called a cell phase

Question 41

what protein tells the cells to divide?

Answer 41

cyclins

Question 42

what are tetrads?

Answer 42

arrangement of 4 chromosomes

Question 43

what is apoptosis?

Answer 43

process of programmed cell death

Question 44

what are stem cells?

Answer 44

undifferentiated cells that become different cell types

Question 45

what is cancer?

Answer 45

uncontrolled cell division, form a mass of cells called a tumor

Question 46

what is a benign and malignant tumor?

Answer 46

benign- does not spread, malignant- invade and destroy

Question 47

what causes cancer?

Answer 47

genetic factors, tobacco, poor diet- lack of physical activity, sun and UV exposure, radiation exposure, carcinogens,

Question 48

how is cancer treated?

Answer 48

radiation, chemo, Immuno, hormone, targeted, stem cell therapy

Question 49

what happens after PMAT II (meiosis II)?

Answer 49

4 daughter cells all genetically different at the end of division

Question 50

what happens in Meiosis I Prophase I?

Answer 50

DNA coils up to chromosomes, spindle fibers begin to form, nuclear membrane disappears

Question 51

what happens in Prophase I?

Answer 51

homologous chromosomes pair up called synapse, each pair of homologous chromosomes are called tetrad, crossing over occurs- homologous recombination

Question 52

what are tetrads?

Answer 52

each pair of homologous chromosomes

Question 53

what is a synapse?

Answer 53

homologous chromosomes pair up

Question 54

what is metaphase I?

Answer 54

tetrads line up along midline, spindle fibers attach to each homologous pairs

Question 55

what is anaphase I?

Answer 55

each homologous pair of chromosomes moves to opposite poles,

Question 56

in anaphase I, what is the random separation of homologous chromosomes called?

Answer 56

independent assortment

Question 57

what happens in telophase I?

Answer 57

same as mitosis, DNA returns to chromatin form, nuclear membranes reform

Question 58

what happens after Meiosis II?

Answer 58

no copying of DNA, similar to the stages of mitosis, end up with four gamete cells at the end of division, all genetically different from each other