3B Gametes

Question 1

gametogenesis

Answer 1

the formation of the gametes by meiosis in the sex organs

Question 2

acrosome(the tip of the sperm)

Answer 2

• membrane-bound storage sites for enzymes that digest the layers surrounding the ovum and allow the sperm’s head to penetrate

Question 3

the nucleus of sperm (the circle located in head, after acrosome) (2)

Answer 3

• contains the highly condensed haploid chromosomes, this condensed state reduces the amount of energy needed to transport it
• its function is that it is haploid to restore the diploid form, to produce the zygote

Question 4

middle piece, after head of sperm (2)

Answer 4

• mitochondria is tightly packed into the middle section

- function= provide the ATP for the lashing of the tail

Question 5

microtubules inside tail of sperm

Answer 5

• produce the whip-like movements of the tail that keep the mature sperm in suspension and help it swim towards the ovum

Question 6

the tail of sperm

Answer 6

a flagellum that propels the sperm by its movement in a liquid environment, to reach ova

Question 7

zona pellucida of ova (3)

Answer 7

• a clear jelly-like layer that surrounds the oocyte
• function= to inhibit polysperm (to block more than one sperm)
• after fert it becomes an inpenetrable barrier so that no more than one sperm can get through

Question 8

label/draw sperm

Answer 8

see book

Question 9

genetic material within, found inside the ova

Answer 9

at the end of first stage of meiosis

Question 10

cortical granules in ova

Answer 10

trigger cortical reaction, to block more than one sperm

Question 11

cytoplasm of ova

Answer 11

has many food reserves

Question 12

draw/label ova

Answer 12

see book

Question 13

What are the tasks that the male gametes (spermatoza) must fulfill? (3)

Answer 13

• must carry the genetic information in the nucleus
• must remain in suspension in the semen so they can be transported through the female reproductive tract (long tail)
• must be able to penetrate the protective barrier around the ovum, which they do using the enzymes in the acrosome

Question 14

what type of nuclei does the pollen grain contain?

Answer 14

two haploid nuclei, one is the tube nucleus and the other is the generative nucleus

Question 15

function of the tube nucleus

Answer 15

producing the pollen tube that penetrates through the stigma, style and ovary and into the ovule

Question 16

function of the generative nucleus

Answer 16

fuses with the nucleus of the ovule to form a new individual

Question 17

structure/function question for sperm

Answer 17

• aerodynamically shaped to reach the ova faster