ch 5- cell division

Question 1

homologous chromosome pairs

Answer 1

two diff versions of the same chromsome number

one from mom and one from dad

Question 2

dyad

Answer 2

replicated chromosomes containing two sister chromatids that look like an X

connected by centromeres

Question 3

what connects sister chromatids

Answer 3

centromeres

Question 4

kinetochores

Answer 4

proteins on the side of centromeres that help microtubules pull sister chromatids apart during cell idvision

Question 5

karyokinesis

Answer 5

division of the nucleus

Question 6

how many autosomes do we have (chromosomes)

Answer 6

22 pairs

Question 7

gametes

Answer 7

haploid cells (sperm and eggs)

Question 8

germ cells

Answer 8

diploid cells that divide by meiosis to produce gametes

Question 9

gametocyte

Answer 9

euk germ cell

can either divide to make more gametocyte or produce gametes

Question 10

what are somatic cells

Answer 10

ALL BODY CELLS EXCEPT GAMETES (haploid)

Question 11

what are the parts of interphase

Answer 11

G1
G0
S
G2

Question 12

90% of the cell cycle happens during what

Answer 12

interphase

Question 13

what happens during G1

Answer 13

cell grows

checks for favourable conditions

if unfavourable it will enter G0

Question 14

what is G0

Answer 14

cells still carry functions but stop cell cycle and do not divide

Question 15

what happens during S phase

Answer 15

cell replicates its genome

centrosome replicates

Question 16

what happens during G2

Answer 16

continues to grow

check DNA for errors

checks for MPF- mitosis promoting factor (maturation promoting factor)

organelles replicated

Question 17

what are the fucntional limitations that lead to cell division

Answer 17

when surface area: volume ratio is too low and when the genome to volume ratio is too low

Question 18

what are the cell specific checkpoints

Answer 18

G1- check for facourable conditions

end of G2- check for errors in DNA and MPF levels

M- check for chromosomal attachment to spindle fibres

Question 19

CDKs

Answer 19

phosphorylate certain substrates to signal cell cycle progression

they depend on cyclin which cycles through stages of synth and degradation

Question 20

growth factors

Answer 20

bind to receptors in th eplasma membrane to signal for cell division

Question 21

density dependent inhibition

Answer 21

halting cell division when density of cells is high

Question 22

anchorage dependence

Answer 22

cells divide only when attached to an external surface

Question 23

what forms the spindle apparatus

Answer 23

the MTOCs

Question 24

MTOCs

Answer 24

organize spindle appartus

ONLY IN EUK-

made up of centrosomes- pair of centromeres- ORGANELLES

Question 25

What are the types of microtubules in the spindle appartus

Answer 25

kinetochore microtubules astral microtubules polar microtubules

Question 26

kinetochore microtubules

Answer 26

extend from centrosomes and attach to kinetochores on chromosomes

Question 27

astral microtubules

Answer 27

extend from centrosomes to the cell membrane to orient the spindle apparatus

Question 28

polar microtubules

Answer 28

extend from the two centrosomes and connect with each other - push centrosomes to opposite ends of the cell

Question 29

pericentriolar material

Answer 29

surrounds centrioles and is responsible for microtubule nucleation (anchoring tubulin to start microtubule extension)

Question 30

prophase

Answer 30

chromatin condenses nucleolus and nuclear envelope dissapear spindle apparatus forms

Question 31

prometaphase

Answer 31

nuclear envelope fragments spindle apparatus microtubules attach to kinetochore of chromosomes

Question 32

when does chromosomes number double

Answer 32

during anaphase

Question 33

cleavage furrow

Answer 33

forms in late anaphase in animal cells contractile ring of ACTIN microfillaments and myosin motors that pinches the cell into two

Question 34

cell plate

Answer 34

in telophase in plant cells created by vesicles form the golgi apparatus and forms middle lamella (cements plant cells together)

Question 35

binary fission

Answer 35

no s phase cells replicate genome DURING cell division NO SPINDLE APPARATUS

Question 36

Meiois I vs II

Answer 36

I- homologous chromosomes separate II- sister chromosomes separate - reductional division

Question 37

when does crossing over occur

Answer 37

prophase I

Question 38

bivalent

Answer 38

tetrads - homologous chromosomes paired up - happens during synapsis between these homologous chromosomes, there is a synaptonemal complex

Question 39

chiasmata

Answer 39

when two chromosomes of a homologous pair cross over during synapsis

Question 40

s phase chromosome numbers

Answer 40

there are 46 chromosomes- after duplication- there are still 46 chromosomes but 92 chromatids during anaphase- we have 92 chromosomes and 92 chromatids and results in 46 chromosomes and 46 chromatids after separation (diploid)

Question 41

number of chromosomes and chromatids in mitosis

Answer 41

prophase - 46. 92 metaphse- 46. 92 anaphase- 92. 92 telophase- 92. 92 separated cells have 46 chromosomes and chromatids

Question 42

number of chromosomes and chromatids in meiosis I

Answer 42

prophase - 46. 92 metaphse- 46. 92 anaphase- 46. 92 telophase- 46. 92 separated cells have 23 chromosomes and 46 chromatids

Question 43

number of chromosomes and chromatids in meiosis II

Answer 43

prophase - 23. 46 metaphse- 23. 46 anaphase- 46. 46 telophase- 46. 46 separated cells have 23 chromosomes and 23 chromatids