CBG 222

Question 1

Cell cycle is divided into

Answer 1

Interphase
Nuclear divisison
Cytokinesis

Question 2

Interphase consist of:

Answer 2

G1, S, G2 & G0

G1 - protein synthesis & growth, cellular content except chr. duplicates, preparation of dna repl. ( 10hrs)

S - DNA replication, chromosome replicated by cell (9 hrs)

G2 - Space for organelles & protein for mitosis to be made. The cell doubles check the duplicated chromosome for error. (4 hrs)

G0 - Resting phase ( nerve cells)

Question 3

Mitosis is the

Answer 3

production of 2 diploid daughter cells with the same DNA by copying their chromosomes.

Question 4

Stages in Mitosis

Answer 4

Prophase
Prometaphase
Metaphase
Anaphase
Telophase

Question 5

How many type of cell division and are:

Answer 5

Two

Mitosis & Meiosis

Question 6

Cell cycle is a

Answer 6

reg pattern of events a dividing cell undergoes

Question 7

2 succ div in Meiosis are:

Answer 7

Meiosis 1 (Reduction)

Meiosis 2 ( Division)

Question 8

Meiosis 1 contains

Answer 8

I P M A 1

Question 9

Prophase 1 has 5 phases:

Answer 9

Leptotene
Zygotene
Pachytene
Diplotene
Diakinensis

Question 10

Prophase 1 phases

Answer 10

Leptotene - chromosome condenses

Zygotene -synapsis occurs to form bivalent which consist of tetrads

Pachytene - crossing over occurs to form chiasma

Diplotene - h. chromosome start to seperate but remain attached at chiasma

Diakinensis - h. Chrm continue to seperate but chiasma moves to end of the chromosome

Question 11

Metaphase 1 and Anaphase 1

Answer 11

Met 1 - h. Chrms line up on d equatorial plate

Met 2 - h. chrms move to opp poles of the cell.

Question 12

Spermatogenesis is divided into 3 phases:

Answer 12

Spermatogonial ( mitosis)

Spermatocyte ( meiosis)

Spermatid ( spermiogenesis/sperm maturation)

Question 13

Spermiogenesis phase:

Answer 13

Golgi
Cap
Acrosome
Maturation

Question 14

Life cycle of sperm

Answer 14

Spermatogonia to

P. spermatocyte ( At d end of mitotic division, spermatogonial phase) to

S. Spermatocyte ( After the end of the Ist meiotic division, as they enter prophase of meiosis 2). to

2 spermatids (At the end of meiosis 2). to

Sperm

Question 15

Life cycle of ova

Answer 15

Oogonia to

P. oocyte ( Become At prophase 1 of meiosis 1). to

S. oocyte & polar body ( Begin meiosis 2 but stop at metaphase 2) to

Fertilized egg and polar body

Question 16

Microsporogenesis is the

Answer 16

formation of 4 haploid microspores by meiosis on angiosperm; the formation of pollen and male gametophyte.

Question 17

Importance of meiosis

Answer 17

Prod. of gametes

Red. in Chrm no.

Maint. of chrm no in somatic cells

Prod. of variation

Question 18

Spermatogenesis takes about how many days & how many are produced

Answer 18

Takes about 74 days

300M cells are produced every day

Question 19

Hormones involved in Oogenesis

Answer 19

FSH
LH
Estrogen
Progesterone

Question 20

Eggs can be into 2 categories:

Answer 20

1) prop. of yolk to cytoplasm of d ovum

2) distribution of yolk granules/platelets in d cyt. of d ova/egg.

Question 21

Egg type according to prop. of yolk to cytoplasm

Answer 21

• Microlecithal eggs : alecithal / oligolecithal / miolecithal
E.g eggs of amphioxus, marsupials & eutherian mammals

2) Mesolecithal eggs : medialecithal eggs.
E.g eggs of many amphibians, ganoid fishes, sharks, diploid

3) Macrolecithal / Polylecithal eggs.
E.g eggs of teleost fishes, gymnophiona, reptiles, birds, monotremes

Question 22

Egg types according to distr. of yolk

Answer 22

Homolecithal / Isolecithall eg Amphioxus, many invertebrates & mammalians eggs

Centrolecithal e.g many insect $ arthropods eggs

Teleolecithal eg birds, reptiles, amphibians, fishes & monotreme eggs

Question 23

Forms of fertilization

Answer 23

Isogamy

Anisogamy/ Heterogamy

Question 24

Cortical reaction is

Answer 24

a process initiated during fertilization by d release of cortical granules from d egg to prevent polyspermy

Question 25

ART means & is used in procedures:

Answer 25

ART - Assisted Reproductive Technology

Used in:
Fertilization Medication
Artificial insemination
In vitro fertilization
Surrogacy
Intracytoplasmic sperm injection (ICSI)
Cryopreservation