3.3.1 - Mammalian Gametes

Question 1

What Are Gametes?
(2 Points)

Answer 1

~ Are the male and female sex cells.

~ Sperm and egg (Ovum) cell.

Question 2

How Is A Zygote Formed?
(2 Points)

Answer 2

~ When gametes fuse together during fertilisation.

~ After the formation of the zygote it divides and develops into a new organism.

Question 3

How Are Gametes Formed?

Answer 3

During meiosis, they only have one copy of each chromosome making them haploid cells.

Question 4

How Many Chromosomes Does A Human Have?

Answer 4

46.

Question 5

How Many Chromosomes Do Gametes Have & What Happens Once Fertilisation Occurs?
(2 Points)

Answer 5

~ 23.

~ Fertilisation creates a zygote with the full number of chromosomes, which is 46 in total and 23 pairs.

Question 6

What Does Combining Genetic Material From 2 Individuals Make?

Answer 6

Genetically unique offspring.

Question 7

Describe How SPERM CELLS Are Specialised For Their Functions
(6 Points)

Answer 7

~ Cell (Plasma) membrane.

~ Acrosome, containing digestive enzymes to break down the zona pellucida of the egg enabling sperm to penetrate the egg.

~ Nucleus.

~ Cytoplasm.

~ Many mitochondria, where respiration takes place releasing energy in the form of ATP for movement of the flagellum.

~ Flagellum, allowing the sperm to swim towards the egg cell.

Question 8

Describe How EGG CELLS Are Specialised For Their Functions
(6 Points)

Answer 8

~ Cell (Plasma) membrane.

~ Nucleus.

~ Cytoplasm, providing energy for the dividing zygote after fertilisation.

~ Much larger than sperm cells, as most of their internal space contains food to nourish a growing embryo.

~ Follicle cells, forming a protective coating.

~ Zona pellucida (Jelly-like glycoprotein layer), forms an impenetrable barrier after fertilisation preventing other sperm cells from entering the egg.