gametogenesis and Meiosis and mitosis

Question 1

Germ cells can only undergo meiosis

true or false

Answer 1

false can undergo both

Question 2

meiosis is only completed in females only once the oocyte is fertilised
true or false

Answer 2

true

Question 3

at 7 months what what stops making more of themselves and what process starts

Answer 3

oogonium and meiosis to make primary oocytes

Primary oocytes by puberty that number decreases

Question 4

do males run out of oogonia

Answer 4

no

but females have a limited number of primary oocytes

Question 5

which type of devision produces genetically unique cells

Answer 5

meiosis

mitosis - identical

Question 6

which type of devision results in diploid cells

Answer 6

mitosis

haploid for meiosis

Question 7

which type of devision only takes place at a certain period in an organisms life time

Answer 7

meiosis

Question 8

are both devisions involved in sexual reproduction

Answer 8

yes

Question 9

what are chromosomes

Answer 9

are linear structures with genes located at specific sites along them

Question 10

what stages of mitosis

Answer 10

prophase
metaphase
anaphase
telophase

Question 11

what happens in early prophase

Answer 11

condensing replicated chromosomes consisting of 2 sister chromatids

mitotic spindle forms as microtubules grow out of centrosomes(made of 2 centrioles) which begin to move away from each other

nuclear envelope intact

Question 12

what happens in pro metaphase

Answer 12

microtubules emerge from centrosomes at poles of mitotic spindle and extend into nuclear region reaching the chromosomes

some of spindle attach to kinetochores

other spindle microtubules make contact with microtubules from opposite poles

nuclear envelope disappears

Question 13

what is a kinetochores

Answer 13

proteins associated with chromosome where spindle attach to pull sister chromatids apart

Question 14

what is metaphase

Answer 14

mitotic spindle fully formed and chromosomes are now midway between spindle poles lined at equator

Question 15

what is anaphase

Answer 15

2 centromere of each chromosome come apart separating the sister chromatids.

Proteins of the kinetochores powered by ATP walk daughter chromosomes along microtubules to opposite poles.

Spindle attached to K shorten and spindle not lengthen
poles then move further apart

Question 16

what is telophase

Answer 16

daughter chromosomes/ chromatid at spindle pole

nucelar envelope around individual chromosome form contractile ring

Question 17

what is cytokinesis - creates cleavage furrow

Answer 17

cytoplasm divides by contractile ring of actin and myosin filaments creating a cleavage furrow

Question 18

what is G1 phase

Answer 18

cell increase in size

Question 19

S phase

Answer 19

DNA réplication occurs during this phase

Question 20

G2

Answer 20

cell continues to grow and energy stores are duplicated

Question 21

G0

Answer 21

cell has left the cell cycle

Question 22

what is somatic cell

Answer 22

any cell that is not a sperm or egg cell

Question 23

what cells can reenter the cell during an immune response

Answer 23

Lymphocytes

Question 24

what happens in prophase 1

Answer 24

pairing and crossing over duplicated homologs ( bivalent) crossing over on bivalents - nuclear envelope breakdown - chiasma
nuclear envelope break down

Question 25

metaphase 1

Answer 25

homolog pairs line up - would be chromatids in mitosis

Question 26

anaphase 1

Answer 26

homologous chromosomes pairs separated moving all chromosome to each cell

Question 27

telophase 1

Answer 27

nucelar envelope around chromosome

Question 28

prophase 2

Answer 28

nuclear envelope gone

Question 29

metaphase 2

Answer 29

chromosomes line up and separate

Question 30

anaphase 2

Answer 30

sister chromatids separated , centrome divide

Question 31

telophase 2

Answer 31

inherits chromatid from each chromosome

Question 32

when does crossing over occur

Answer 32

prophase 1

Question 33

what protein lattice holds homologous chromosomes together in early prophase 1 and in perfect alignments

Answer 33

synaptonemal complex

Question 34

what is an oocyte

Answer 34

immature egg cell - prophase 1

Question 35

in what stage of the cell cycle is a secondary oocyte formed and haploid

Answer 35

metaphase 2

Question 36

spermatogonium

Answer 36

diploid cell twice mitosis and meiosis 1 and meiosis 2 to form 4 spermatids - haploid - then form mature spermatozoa

Question 37

germ cell

Answer 37

any cell that gives rise to the gametes - diploid

Question 38

when do germ cells arise

Answer 38

during the primitive streak

Question 39

at what time to oogonium turn to primary oocyte

Answer 39

7 months