B5: Fertilisation and the Development of the Foetus

Question 1

What is the scientific term for reproductive cells (egg and sperm cells)?

Answer 1

Gametes

Question 2

The male gametes are…

Answer 2

Sperm cells

Question 3

The female gamete is the

Answer 3

Egg cell (Ovum)

Question 4

When an egg and sperm nuclei fuse together, we call it…

Answer 4

……fertilisation

Question 5

The oviducts are lined with cells lined with small hair like structures called…

Answer 5

Cilia

Question 6

What is the function of the cilia that line the oviducts?

Answer 6

They waft the egg released by the ovary along to the uterus.

Question 7

What happens after fertilisation?

Answer 7

1. The fertilised egg divides into a ball of cells called an embryo. 2. The embryo attaches to the lining of the uterus and begins to develop into a baby. This is called implantation.

Question 8

How often is an egg released from an ovary?

Answer 8

Once a month

Question 9

Where does fertilisation occur?

Answer 9

The Oviduct

Question 10

Why can only one sperm fertilise the egg?

Answer 10

The membrane of the egg (ovum) thickens when the first sperm has penetrated.

Question 11

What is the scientific name for an egg that has been fertilised?

Answer 11

A zygote

Question 12

What is the function of the umbilical cord?

Answer 12

It connects the fetus to the placenta.

Question 13

In mammals, the time spent in the uterus during development is called…

Answer 13

….gestation

Question 14

What effect can smoking have on an unborn baby?

Answer 14

Premature birthLow birth weight

Question 15

What is the function of the fluid sac (amniotic sac)?

Answer 15

It acts as a shock absorber, protecting the foetus from any bumps.

Question 16

What is the function of a placenta?

Answer 16

* An organ where substance pass between the mother’s blood and the fetus’s blood. * It acts as a barrier, which stops infections and harmful substances reaching the foetus.

Question 17

What effect can alcohol have on an unborn baby?

Answer 17

Poor brain development

Question 18

How long is the human gestation period?

Answer 18

9 months (40 weeks)

Question 19

Does the blood of mother and fetus mix when it is developing in the uterus?

Answer 19

NO - but useful substances like nutrients and oxygen can pass from mother to baby through the placenta.

Question 20

When a fertilised egg (zygote) divides into a ball of cells, we call the ball of cells an…

Answer 20

embryo

Question 21

The menstrual cycle lasts for…

Answer 21

28 days (approximately)

Question 22

What happens on day 1 of the menstrual cycle?

Answer 22

Bleeding as the lining of the uterus breaks down.

Question 23

What is the function of the uterus lining?

Answer 23

To provide a spongy, blood rich layer for embryo implantation.

Question 24

What happens on day 14 of the menstrual cycle?

Answer 24

Ovulation - an egg is released from one of the ovaries.

Question 25

What happens if a sperm cell does not meet the egg after ovulation has happened?

Answer 25

The lining of the uterus breaks down and the menstrual cycle starts again from day 1.