Life Science- Fertilisation And Pregnancy

Question 1

Both male and female

Answer 1

Are needed to produce sexually

Question 2

When man and woman have

Answer 2

Intercourse, the man places his erect penis inside the woman’s vagina; copulation.

Question 3

Penis ejaculates

Answer 3

Semen into the vagina. Sperm swim up through the uterus and into the Fallopian tubes. If there is an ovum in one of the Fallopian tubes, the sperm fuses with the ovum to form a zygote

Question 4

Fusion of sex cell

Answer 4

Fertilization. The first stage of pregnancy

Question 5

If fertilization occurs

Answer 5

We say the woman has conceived

Question 6

Few hours after fertilization

Answer 6

Zygote divides into many cells until a ball of cells is formed. While the zygote is dividing, it moves along the Fallopian tube to the uterus.

Question 7

Ball of cells

Answer 7

Attaches itself to the spongy tissue layer of the endometrium on the uterus; implantation. Uterus holds the ball of cells securely. It won’t call out unless something goes wrong with the uterus lining or cells

Question 8

Once zygote has

Answer 8

Implanted itself into the endometrium of the uterus, a special disc-like structure forms to feed it; placenta.

Question 9

Substances such as

Answer 9

Nutrients, oxygen and waste products move between the blood of the developing embryo and the mother in the placenta, but their blood never mixes.

Question 10

Developing embryo is

Answer 10

Attached to the placenta by the umbilical cord

Question 11

Zygote divides and

Answer 11

Grows into an embryo. After a few weeks the cells start to change to become muscles, bones, heart and blood vessels.

Question 12

From week 8

Answer 12

Embryo is called a foetus. Foetus remains in the uterus until it is ready to be born

Question 13

Gestation

Answer 13

Period from fertilization to birth. Approximately 40 weeks in humans

Question 14

Embryo is surrounded

Answer 14

By amniotic sac that is filled with amniotic fluid.

Question 15

Amniotic sac

Answer 15

Protects the developing embryo in the uterus of the mother

Question 16

As the foetus grows

Answer 16

It begins to kick and move, it sleeps and sucks its thumb. It can hear the mother’s heart beating and the sounds of people talking. Some even have hiccups whilst in the uterus.

Question 17

Placenta stops

Answer 17

Many harmful substances that could be in the mother’s blood from reaching the foetus, but it can’t protect the baby against nicotine, alcohol, other drugs and micro-organisms such as syphillis and rubella