Topic 2 (Reproduction)

Question 1

The structure of sperm cell (4)

Answer 1

1)Haploid nucleus
2)Acrosome
3)Mitochondira
4)Small

Question 2

The function of acrosome (2)

Answer 2

1)Release digestive enzymes
2)To digest the zona pellucida

Question 3

The function of mitochondria in sperm cell (2)

Answer 3

1)Produce ATP via respiration
2)For fertilisation

Question 4

The structure of oocyte (5)

Answer 4

1)Lipid droplet
2)Large cytoplasm
3)Zona pellucida
4)Cortical granule
5)Haploid nucleus

Question 5

The function of lipid droplet in a oocyte

Answer 5

Source of energy for future division and growth

Question 6

The adaption of large cytoplasm in a oocyte

Answer 6

Allows the fusion of sperm cell nuclei during fertilisation

Question 7

The adaptation of zona pellucida

Answer 7

1)The cortical granule causes it to harden once one sperm has reached its nuclei
2)Prevents polyspermy

Question 8

Adaptation of haploid nucleus in gametes

Answer 8

Can be restored back to diploid during fertilisation

Question 9

The stages of oogenesis (4)

Answer 9

1)Primary oocyte undergo meiosis from before birth and halted at prophase I
2)At puberty, meiosis I completes and is halted at meiosis II which produce the first polar body and a secondary oocyte
3)Secondary oocyte released at ovulation and only complete Meiosis II if fertilised
4)If fertilised, a secondary polar body is produced

Question 10

The stages of spermatogenesis

Answer 10

1)Primary spermatocyte (diploid)
2)Undergo meiosis I to produce secondary spermatocyte
3)Meiosis II to produce spermatids
4)Differeciate into specialised spermatozoa

Question 11

The process of fertilisation (9)

Answer 11

1)The sperm reaches the oocyte
2)Acrosome reaction
3)Fusion of two membranes
4)Cortical reaction
5)Secondary oocyte completes meiosis II
6)nuclear envelope disappear
7)Chromosome fuses becoming a diploid zygote
8)Undergo cleavage division
9)Impants to the uterus as blastocyst

Question 12

The stages of acrosome reaction (2)

Answer 12

1)Sperm binds to zona pellucida
3)Acrosome secretes digestive enzyme

Question 13

The stages of cortical reaction (3)

Answer 13

1)Exocytosis of cortical granule
2)Fuse with zona pellucida
3)Forming fertilisation membrane

Question 14

The stages of microsporogenesis (3)

Answer 14

1)Microspore undergo meiosis to produce 4 haploid cells
2)Each undergo mitosis
3)Produce one pollen tube nucleus and one generative nucleus

Question 15

The stages of megasporogenesis

Answer 15

1)megaspore divide by meiosis into 4 haploid megapores
2)3 degenerates
3)One undergo 3 mitosis
4)Which produce one gamete, two polar nuclei and 5 other cells

Question 16

The process of fertilisation in plant (4)

Answer 16

1)Pollen lands on stigma triggers generative nucleus to undergo mitosis
2)Pollen tube nuclei secretes enzyme to digest style tissue
3)Pollen tube grows towards the ovary and enters the embryo sac via the micropyle then degenerates
4)double fertilisation occur

Question 17

What happens during double fertilisation (2)

Answer 17

1)One generative nucleus fuse with female gamete (zygote)
2)One generative nucleus fuse with 2 polar nuclei (triploid endosperm cell)