Cell continuity

Question 1

cell continuity

Answer 1

existing cells divide and produce new cells

Question 2

genome

Answer 2

all the genetic material in an organism

Question 3

where is most of the DNA in the cell found

Answer 3

in the nucleus

Question 4

how is DNA organised

Answer 4

into structures called chromosomes

Question 5

Chromosomes

Answer 5

thread like structures in the nucleus

Question 6

what are chromosomes composed of

Answer 6

DNA and protein

carry thousands of genes

Question 7

in a non-dividing cell, describe the chromosomes

Answer 7

uncoiled and form a tangled mass called chromatin

Question 8

when a cell is dividing, describe the chromosomes

Answer 8

they contract and thicken

Question 9

haploid cell

Answer 9

has one set of chromosomes

– one of each type of chromosomes

Question 10

diploid cell

Answer 10

has two sets of chromosmes

– two of each type of chromosme

Question 11

n represents

Answer 11

haploid cell

Question 12

2n represents

Answer 12

diploid cell

Question 13

what describes the sequence of events in a dividing cell

Answer 13

the cell cycle

Question 14

interphase

Answer 14

the non-dividing cell

Question 15

what happens to the cell during interphase

Answer 15

it grows and increases in size

Question 16

what do cells make during interphase

Answer 16

proteins, lipids

Question 17

what happens to during organelles interphase

Answer 17

they are replicated

• mitochondria
• chloroplasts
• ribosomes

Question 18

what happens to the DNA during interphase 2

Answer 18

it uncoils

it makes a copy of itself

Question 19

what hold the identical chromosomes together

Answer 19

a centromere

Question 20

what happens to the nucleus during division

Answer 20

it divides (mitosis)

Question 21

what happens to the cytoplasm during division

Answer 21

it divides (cellular division)

Question 22

all body cells in organisms of the same species have

Answer 22

the same number of chromosmes

Question 23

during growth and cell multiplication, what must be kept constant

Answer 23

the number of chromosomes per cell must be kept constant

Question 24

what does mitosis produce

Answer 24

2 identical daughter cells

Question 25

explain how the 2 daughter cells are identical

Answer 25

the same number and same type of chromosomes

Question 26

what cells can divide by mitosis

Answer 26

haploid and diploid cells

Question 27

4 stages of mitosis in order

Answer 27

prophase, metaphase, anaphase and telophase

Question 28

when does interphase occur

Answer 28

between miotic divisions

Question 29

describe chromosomes during interphase

Answer 29

uncoiled and not visible

Question 30

3 things that happen during interphase

Answer 30

DNA replicates molecules are synthesised organelles are replicated

Question 31

DNA replicating

Answer 31

an identical copy of each chromosome is made

Question 32

what has happened by the end of interphase? 3

Answer 32

the chromosomes will have duplicated and begin to become visble spindle fibres will be forming the nuclear membrane will be breaking down

Question 33

describe the chromosomes during prophase

Answer 33

they become shorter and visible as threads | each chromosome has replicated to make two identical chromosomes joined at the centromere

Question 34

spindle during prophase

Answer 34

the spindle forms

Question 35

nucleus during prophase

Answer 35

nuclear membrane breams down

Question 36

chromosome during metaphase

Answer 36

chromosmes line up on the equator of the cell

Question 37

centomeres during metaphase

Answer 37

centromeres are attached to spindle fibres frome each side of the cell

Question 38

3 steps of anaphase

Answer 38

centromeres split spindle fibres contract identical chromosomes separate and are pulled to opposite poles of the cell

Question 39

3 steps of telophase

Answer 39

chromosomes uncoil and begin to revert to chromatin nuclear membranes form nuclei are formed

Question 40

what is cytoplasm divided by in an animal cell

Answer 40

a cleavage furrow forming along the equator | cell is pinched in two

Question 41

what do separates the cytoplasm in a plant cell

Answer 41

divided by a cell plate forming across the middle of the cell cell membranes and cell walls are formed on each side of the plate

Question 42

2 results of mitosis

Answer 42

2 identical daughter cells | chromosome number is kept constant (have the same number as the parent)

Question 43

genetic information in daughter cells in mitosis

Answer 43

identical genetic material and information passes into each new cell

Question 44

role of mitosis in unicellular organisms

Answer 44

reproduction

Question 45

3 roles of mitosis in multicellular organisms

Answer 45

growth replacement of cells repair of tissues

Question 46

location of mitosis in plants

Answer 46

root tips, shoot tips, meristems, buds

Question 47

location of mitosis in animals

Answer 47

skin (epithelium), bone marrow

Question 48

what does meisois mean?

Answer 48

reduction divison

Question 49

2 results of meiosis

Answer 49

a diploid nucleus divides by meiosis to form 4 daughter cells with half the number of chromosomes present inthe parent cells the daughter cells are genetically different

Question 50

what are gametes

Answer 50

haploid cells that can fuse (sex cells)

Question 51

what are special about the gamete nuclei

Answer 51

they have half the number of chromosomes present in the parent nuclei

Question 52

what does meiosis produce

Answer 52

haploid gametes

Question 53

2 roles of meiosis

Answer 53

sexual reproduction | genetic variation

Question 54

what happens to genes during meiosis

Answer 54

genes are separated producing ddifferent arrangements every time

Question 55

how does meiosis produce genetic variation

Answer 55

daughter cells are always different

Question 56

2 locations of meiosis in animals

Answer 56

testis//ovary

Question 57

2 locations o meiosis in plants

Answer 57

anther//ovule

Question 58

2 characteristics of mitosis that are different meiosis

Answer 58

number of chromosomes stays constant | daughter cells are identical

Question 59

2 characteristics of meiosis that are different mitosis

Answer 59

number of chromosomes is halved | daughter cells are different

Question 60

definition of cancer

Answer 60

a group of disorders of the body in which cells lose the normal control of mitosis

Question 61

benign tumours

Answer 61

do not move and invade

Question 62

malignant tumours

Answer 62

spread and can be life threataning

Question 63

metastisis

Answer 63

the spread of cancer

Question 64

mutations

Answer 64

can change normal cells into cancer cells

Question 65

what is cancer caused by?

Answer 65

mutagens

Question 66

5 mutagens

Answer 66

``` radiation chemicals cigarette smoke asbestos some viruses ```