Reproduction and growth

Question 1

What is mitosis?

Answer 1

Its a type of cell division in which a diploid cell copies itself and finally divides into 2 identical diploid daughter cells. All the daughter cells are identical

Question 2

How many chromosomes are in a diploid human cell?

Answer 2

46 chromosomes

Question 3

Explain the process of mitosis?

Answer 3

The cell grows
DNA is copied to form 2 copies of each chromosome. These copies are joined together at a single point
The nuclear membrane breaks down
The chromosomes line up across the centre of the cell
The copies of chromosomes are pulled apart and move to opposite ends of the cell
The cytoplasm and cell membrane divide to form 2 different cells

Question 4

What are chromatids?

Answer 4

Copies of cell DNA

Question 5

What is meiosis?

Answer 5

A type of cell division which gives rise to cells that are genetically different.

Question 6

Where does meiosis take place?

Answer 6

In the sex organs

Question 7

What are the type of cells formed from meiosis?

Answer 7

Gametes

Question 8

How many chromosomes are in a haploid human cell?

Answer 8

23 chromosomes

Question 9

Explain the process of meiosis?

Answer 9

Parent cell grows
DNA replicates to form 2 copies of each chromosome, they are then joined together at a single point (centromere)
nuclear membrane breaks down
Homologous pairs of the chromosomes join together
The pairs exchange sections of dna
They attach to the spindle fibres
They are pulled apart and move to opposite ends of the cell
The cell divides
This process repeats with the new cells

Question 10

What are sperm?

Answer 10

Sperm have a tail like flagellum that moves through the water

Question 11

What are egg cells?

Answer 11

Produced monthly in female humans from the ovaries

Question 12

What is external fertilisation?

Answer 12

In fish, they release the egg and the sperm into the water and the sperm swim through the water to the egg. Occurs outside the body

Question 13

What is internal fertilisation?

Answer 13

Male animals including birds and mammals release there sperm into the bodies of females. Fertilisation occurs inside the female.

Question 14

What is fertilisation?

Answer 14

When a haploid sperm cell and a haploid egg cell fuse together to make a diploid cell

Question 15

What is a zygote?

Answer 15

The first cell that is formed through fertilisation

Question 16

What is the ovary?

Answer 16

Where the egg cells are formed by meiosis. Produces hormones oestrogen and progesterone

Question 17

What is the oviduct?

Answer 17

Egg cells travel down this to the uterus. Lined with cilia which move the cell. Site of fertilisation

Question 18

What is the uterus?

Answer 18

A lining forms in the uterus, where the embryo will implant. The foetus develops in the uterus, which has a thick muscular wall. This contracts during labour

Question 19

What is the cervix?

Answer 19

Narrow opening to the uterus. This widens during labour, to allow the baby to be born

Question 20

What is the vagina?

Answer 20

Muscular tube that leads from the cervix to the outside of the womans body

Question 21

What are the testes?

Answer 21

Where sperm cells are formed by meiosis. Produces the hormone testosterone

Question 22

What is the sperm duct?

Answer 22

Maturing sperm are transported through this tube

Question 23

What are the seminal vesicles and prostate gland?

Answer 23

Release liquids into the sperm duct which mixes with the sperm cells to form semen. Provides nutrients for the sperm

Question 24

What is the Urethra?

Answer 24

Tube inside penis which can transport either urine or semen