Cell Division

Question 1

cell continuity

Answer 1

all cells develop from pre existing cells, in order to do this all living cells need to divide

Question 2

function of cell division on unicellular organisms

Answer 2

asexual reproduction

Question 3

function of cell division in multicellular organisms

Answer 3

growth and repair of cells
sexual reproduction

Question 4

what are chromosomes?

Answer 4

thread like structures found in nucleus

Question 5

how many chromosomes are in each human cell?

Answer 5

23 pairs ie 46 total

Question 6

composition of chromosomes

Answer 6

DNA and Protein

Question 7

genes

Answer 7

lengths of DNA that code for the production of a protein

Question 8

diploid

Answer 8

cells with 2 types of each chromosome

Question 9

what symbol is given to diploid cells

Answer 9

2n

Question 10

what are matching chromosomes called?

Answer 10

homologous pairs

Question 11

haploid

Answer 11

one type of each chromosome ie egg and sperm

Question 12

what symbol is given to haploid cells

Answer 12

n

Question 13

what are the 2 phases of the cell cycle

Answer 13

cell division
interphase

Question 14

what is interphase

Answer 14

the stage of the cell cycle where the cell is not dividing

Question 15

how much time does interphase take up

Answer 15

roughly 90%

Question 16

what processes occur during interphase

Answer 16

cell growth
DNA replicates
organelles are made

Question 17

make up of chromatin

Answer 17

DNA and protein

Question 18

when is chromatin present

Answer 18

interphase

Question 19

when are chromosomes present

Answer 19

dividing

Question 20

differences between chromatin and chromosomes

Answer 20

CHROMOSOMES
tightly packed DNA
condensed thick fibres
cell is dividing
chromosomes are paired

CHROMATIN
unravelled DNA
elongated, thin fibres
cell is not dividing
chromatin not paired

Question 21

mitosis

Answer 21

form of nuclear division in which 1 nucleus divides to for 2 daughter nuclei each with the same no of chromosomes and identical genes

Question 22

meiosis

Answer 22

form of nuclear division in which 1 nucleus divides to give 4 nuclei each with half the number of chromosomes as the parent.

Question 23

role of mitosis

Answer 23

growth and repair
asexual reproduction

Question 24

what are the 4 stages of mitosis

Answer 24

prophase
metaphase
anaphase
telophase
(pour me another tea)

Question 25

chromatid pairs

Answer 25

all chromosomes replicate themselves before cell division. the 2 precise identical chromosomes are called a chromatid pair

Question 26

centromere

Answer 26

structure on chromosomes that holds a pair of chromatids together

Question 27

centriole

Answer 27

organelle in cytoplasm that produces spindle fibres

Question 28

spindle fibres

Answer 28

filaments that attach to chromosomes during mitosis to move chromosomes and pull chromatid pairs apart

Question 29

describe prophase

Answer 29

-chromosomes contract and become visible -spindle fibres are forming -nuclear membrane is breaking down

Question 30

describe metaphase

Answer 30

-chromosomes are line dup along the equator -spindle fibres are attached to chromosomes at centromere -centrioles are at opposite poles of the cell

Question 31

describe anaphase

Answer 31

-spindle fibres contract -single strand from each chromosome pair is pulled to either pole of the cell

Question 32

which is the shortest phase

Answer 32

anaphase

Question 33

describe telophase

Answer 33

nuclear membrane has reformed spindle fibres are broken down chromosomes have elongated again 2 nuclei are formed that are genetically identical

Question 34

explain cytokinesis in animal cells

Answer 34

cell membrane drawn inwards at equator forming a cleavage furrow which eventually splits cell in 2

Question 35

when does cytokinesis occur?

Answer 35

straight after telophase

Question 36

explain cytokinesis in plant cells

Answer 36

cell plate forms along the equator cell plate divides the cell and middle lamella fills the region between the 2 new cells

Question 37

what are vessicles made from

Answer 37

cellulose

Question 38

what makes the cell plate

Answer 38

vesicles

Question 39

function of meiosis

Answer 39

sexual reproduction variation in population

Question 40

list the differences between meiosis and mitosis

Answer 40

mitosis 2 daughter cells same no of chromosomes in parent and daughter cells daughter cells are genetically identical to parent meiosis 4 daughter cells half no of chromosomes in daughter cells daughter cells are genetically different to each other

Question 41

cancer

Answer 41

a group of disorders in which a certain cells lose the ability to control the rate of mitosis

Question 42

how do tumours form

Answer 42

cells that lose control of their mitosis rate form a mass of cells ie a tumour

Question 43

benign tumour

Answer 43

non life threatening tumours. it is formed but does not invade or interfere with the functioning of other cells or tissues

Question 44

malignant tumours

Answer 44

this mass of cells may be harmful to other cells and tissues in the body preventing the efficient functioning of other cells

Question 45

metastasis

Answer 45

the movement of tumours through the blood system to another part of the body, further invading the body

Question 46

what is a carcinogen

Answer 46

a cancer causing agent

Question 47

give examples of carcinogens

Answer 47

UV rays, cigarrettes, vapes, tobaco

Question 48

treatments of cancer

Answer 48

surgery, chemo, radiation therapy

Question 49

why cant red blood cells undergo mitosis?

Answer 49

they do not have a nucleus and no mitochondria

Question 50

what type of division can haploid cells go through?

Answer 50

mitosis only

Question 51

what type of division can diploid cells go through?

Answer 51

both