D2.1

Question 1

cytokensis

Answer 1

cell division

Question 2

animal cytokensis steps

Answer 2

• cleavage furrow forms in cell centre
• actin and myosin proteins form a parallell ring around plasma membrane
• this also forms in cell centre
• contractions in protein pulls the membrane together causing seperation

Question 3

plant cytokensis steps

Answer 3

• vesicles carrying carbs, lipids and proteins make 2 plasma membranes
• vesciles carrying pectin and cellulose form new cell wals in centre called cell plate
• cell splits

Question 4

process of oogensis

Answer 4

oogonium - mitosis 2 x in womb
a diploid cell - secondary oocyte undergoes meosis. there is 2 haploids.
one is called the first polar body and like gets reabsorbed
- the one that survived mesosis again and forms ovum
second polar body leaves

Question 5

processes of mesis and mitosis

Answer 5

i

P
m
A
T

c

Question 6

interphase

Answer 6

both stages of growth getting ready to split happens here

growth 1
dna replication
growth 2

Question 7

when does DNA replication happen

Answer 7

during interphase

Question 8

dna replication process

Answer 8

• chromosone
• replicates and becomes cromatid with the two sisters
• splits and is still the same chromosone

Question 9

purpose of histones

Answer 9

supercoil dna to form cromatin during prophase

Question 10

spindle mictrotubules

Answer 10

• attatch tublin to the ends for growth
• motors in the centre called kinetochore on the chromosones atttatch tubules

Question 11

two types of un even splitting

Answer 11

• ooegensis
• budding in yeast

Question 12

when does nuclesus divide

Answer 12

interphase
before the cell devides
if nuclesus doesnt split then the cells will be anucleate and cant survive

Question 13

prophase mitosis

Answer 13

• early prophase is the condensation of dna into chromatids
• sister cromatids form
• centrioles move to either end of the cell
• mictrotubules begin to grow
• late the chromosones fully condense and nuclear membrane breaks down

Question 14

metaphase mitosis

Answer 14

• centrioles meet opposite ends
• spindles grow
• chromosones line up in crentre
• spindles attatch to centromere, specifically kinetochores

Question 15

anaphase mitosis

Answer 15

• the sisters separate
• spindles shorten to pull to opposite ends
• chromatids become chromosones
• pulled to opposite poles

Question 16

telophase mitosis

Answer 16

• chromosones decondense
• nucler membranes reform
• nuceloli form

Question 17

how do IPMAT look in a mitroscope

Answer 17

• interphase nucleus is a dark circle, no chromosones visible
• prophase chromosones vibisbe, membrane breaks
• metaphase see the alignment
• anaphase v shape structures move to poles
• teolphase, splitting anc consesing

Question 18

what does mitosis produce

Answer 18

two diploid cells with identical chromosones
goes from 1 chroatid - 2 chromatid - 1 but remains diploid the whole way

Question 19

what types of devison is meosis

Answer 19

reduction divison
the mothers deiploid halfs to form two haploid

Question 20

homologous chromosones

Answer 20

pairs of chromosones that are similar and thus pair up in meosis 1
they have the same genes but different allels

Question 21

meosis prophase 1

Answer 21

• chromosones condense at this point theres two chromatids
• they meet their pairs
• this is where condesning happens

Question 22

metaphase 1 meosis

Answer 22

• chromosones align with their pair in the middle
• spindle fibres attatch to centromere, kienochore

Question 23

anaphase 1 meosis

Answer 23

• homologous pairs are separted and pulled to opp ends of cell

Question 24

telophase 1 meosis

Answer 24

• the cell is now haploid.
• there is two cells with half the number of chromosones
• they are still chromatids with their sister

Question 25

prophase 2 meosis

Answer 25

- no crossing over or pairs - dna doesnt replicate - spingles grow again

Question 26

metaphase 2 meosis

Answer 26

- re lign up

Question 27

anaphase 2 mesosis

Answer 27

- sister cromatids seperate like in mitosis

Question 28

telophase

Answer 28

- the cell splits - dna decondeses - each is different

Question 29

trisomy

Answer 29

an extra chromosome

Question 30

when does none disjunction occur

Answer 30

when chromosones dont split properly in anaphase 1 or 2

Question 31

consequence of none disjucntion

Answer 31

when the cells dvide one can end up with extra chromones, and one can end up with none

Question 32

down syndrome

Answer 32

during anaphase 1, the 21st set of chromosones fails to seperate and there is 47 instead of 46

Question 33

variation - crossing over

Answer 33

- happens when homologous chromosones pair up - they are bivalent, with one from each poarent - chromosones break down and re join - jeans exchnage from each parent - new combinations

Question 34

variation - random orientation of bivalents

Answer 34

when they line up during metaphase they can line up in any order, this determins what genes are inherited into each cell this process is completly random and independent gives 8.000.000 plus posibilities

Question 35

solvent

Answer 35

liquids that can dissolve other substances to make solutions

Question 36

solutes

Answer 36

the dissolved substance in solutions

Question 37

solvatation

Answer 37

the process of dissolving. water does this though forming hyrogen bonds with molecules - other polars

Question 38

hyerpotonic solution

Answer 38

more solute in solution than thing(high outside low inside) - shrinks - net movement out of thing

Question 39

hypotonic solution

Answer 39

less solute in solution than thing (high inside low outside) - expands/burst - net movement of water in thinf

Question 40

isotonic solution

Answer 40

the same concentration as the thing - same same - no net movement

Question 41

uniceullular cells are hyper or hypo

Answer 41

hypertonic to environment meaning they have more solute in the cell than environment so the use CONTRACTILE VACUOLES to prevent bursting

Question 42

in animal cells solutions are

Answer 42

kept isotonic to the cell

Question 43

hypotonic solution cell wall

Answer 43

- water centres cell into vacuole - turgor pressure increases beacuse protoplast expands - cell becomes fully turgid - walls prevent bursting - without turgour pressure plants cant stand tall and wilt

Question 44

in a hypertonic solution w cell wall

Answer 44

- colume decreases - protoplast shrinks