Reproduction part 3 and 4

Question 1

What does the amniotic cavity contain?

Answer 1

It contains the amniotic fluid that
1. Supports and allows foetus to move freely
2. Protects foetus from mechanical shock
3. Lubricates vagina during childbirth
4. Maintains a constant internal environment for the foetus.

Question 2

What happens eight weeks after fertilisation?

Answer 2

The embryo develops into a foetus.

Question 3

Pregnancy lasts about ____ months in humans.

Answer 3

Pregnancy lasts about 9 months in humans.

Question 4

What happens at the end of the pregnancy?

Answer 4

The muscles of the uterus contract to push out the fully formed baby.
The cervix enlarges to allow the baby to pass through.

Question 5

What is the difference between zygote, embryo, foetus and baby?

Answer 5

A zygote is form during fertilisation when there is a fusion of the nucleus of the ovum and sperm.

The zygote divides to form an embryo.

A foetus is when the embryo is at 9th week of birth.
8 weeks after fertilisation, the embryo develops into a foetus.

Question 6

What happens when the single-celled zygote divides to form an embryo?

Answer 6

It moves down the oviduct towards the uterus with the help of the cilia lining the oviduct and peristalsis of the oviduct walls.

Question 7

The embryo reaches the uterus and embeds itself in the uterine lining how many days after fertilisation? And what is this process called?

Answer 7

5 to 7 days. This process is called implantation.

Question 8

The embryo produces villi, which penetrates the uterine lining to form the ____.

Answer 8

Placenta

Question 9

The _______ ____ is the membrane that encloses the embryo/foetus in the amniotic cavity.

Answer 9

Amniotic sac

Question 10

What does the embryonic villi do?

Answer 10

The embryonic villi absorbs nutrients

Question 11

What is the feature of the embryonic villi?

Answer 11

The embryonic villi has an elongated shape which increases surface area to volume ratio for more efficient of absorption of nutrients. The finger-like projections called embryonic villi containing foetal blood capillaries increase surface area to volume ratio for efficient exchange of dissolved substances.

Question 12

What does the placenta consists of?

Answer 12

The placenta consists of the uterine lining on which embryo/foetus is attached.
Maternal blood spaces
Finger-like projections called embryonic villi (containing foetal capillaries)

(amniotic sac is NOT inside the placenta The amniotic sac is a fluid-filled sac that surrounds and protects the developing fetus. It is located outside of the placenta. The placenta is an organ that attaches to the uterine wall and is connected to the fetus by the umbilical cord. The placenta is responsible for exchanging nutrients, oxygen, and waste products between the mother and fetus.

Think of it like this: The placenta is a bridge connecting the mother and fetus. The amniotic sac is a protective bubble that surrounds the fetus while it’s in the womb.
by GEMINI)

Question 13

What hormone does the placenta secrete?
A Progesterone
B Oestrogen
C It does not secrete any hormone
D Progesterone and oestrogen

Answer 13

The placenta secretes progesterone and oestrogen to maintain a healthy pregnancy.

Question 14

What does the placenta do? Describe the arteries and veins related.

Answer 14

The placenta facilitates exchange of dissolved substances between maternal blood spaces and foetal blood capillaries through diffusion and active transport.

The umbilical cord connects the foetus to the placenta.
— Two umbilical arteries transport metabolic wastes such as urea and dissolved carbon dioxide from foetus to mother.
—One umbilical vein transports glucose, amino acids, fatty acids, glycerol, mineral salts, dissolved oxygen and some antibodies (that protect the foetus against diseases) from mother to foetus.

Finger-like projections called embryonic villi containing foetal blood capillaries increase surface area to volume ratio for efficient exchange of dissolved substances.

Speed of blood is slower in foetal blood capillaries to allow more time for exchange of dissolved substances due to increased total cross-sectional area of the blood capillaries for the same flow rate (m cube/s) of blood.

Question 15

What should you take note when labelling diagrams?

Answer 15

Check for singular or plural

Question 16

Given that you can associate metabolic wastes as “bad things” (just an e.g.) and nutrients as “good things”, choose the best option(s) that represents the exchange of substances between maternal blood spaces and foetal blood capillaries.

A Some “bad things” go to child from mother.
B Some “good and bad things” go to child from mother.
C “bad things” go from child to mother.

Answer 16

B and C

Question 17

Why is there no direct contact between maternal and foetal blood?

Answer 17

Higher blood pressure of mother may be fatal to foetus.
Possible incompatibility between blood groups of mother and foetus may result in agglutination of blood.
Some harmful substances and microorganisms cannot directly enter the foetal blood.

Question 18

What are some things that can have a great impact on foetal development?

Answer 18

Lifestyle and diet.

Question 19

What should a pregnant woman not consume?

Answer 19

She should not consume alcohol, smoking and abuse of controlled drugs such as cocaine.

Question 20

What are the negative effects of some substances on Foetus?

Answer 20

Sudden Infant death syndrome
Foetal alcohol syndrome
Low birth weight
Premature birth
Smaller head circumference (developmental delay)
Birth defects
Placenta detachment and bleeding. (For this one, the negative consequences is more for the mother because it will be painful I think)

Question 21

Is abortion a birth control method?

Answer 21

No

Question 22

What is contraceptives?

Answer 22

Birth control

Question 23

What is the purpose of birth control?

Answer 23

Birth control allows for family planning according to one’s financial and health needs. It also helps a country in preventing overpopulation.
They prevent conception by preventing ovulation, fertilisation or implantation of embryo.

Question 24

What are the two types of contraceptives?

Answer 24

Temporary: Behavioural, barrier, hormonal, chemical and intrauterine contraception

Permanent: Surgical contraception.

Question 25

What is abstinence?

Answer 25

Abstinence is a behavioural contraception. It is a choice to refrain from sexual intercourse and/or sexual contact. It prevents sperm from entering the vagina and thus prevent fertilisation. Refraining from all forms of sexual contact gives the best protection against sexually transmitted infections (STIs)

Question 26

Is abstinence free or not free?

Answer 26

It is free.

Question 27

What is the percentage of success in preventing pregnancy for abstinence?

Answer 27

Highest (100%) success in preventing pregnancy.

Question 28

What is a disadvantage of abstinence?

Answer 28

Many find it difficult to adhere to

Question 29

What is the withdrawal/pull out method?

Answer 29

-Behavioural contraception
-When a man removes his penis out of the vagina during sexual intercourse and ejaculates outside the vagina and away from the female’s external genitalia. Prevents sperm from entering the vagina and thus preventing fertilisation.

Question 30

Is the withdrawal/pull out method free or not free?

Answer 30

Free

Question 31

What is/are the disadvantageous of withdrawal/pull out method for birth control?

Answer 31

Low success (73-96%) in preventing pregnancy
Does not protect against STIs
Requires willpower and experience from the male partner
Male’s pre-ejaculate may contain sperm

Question 32

What is the rhythm method for birth control?

Answer 32

Behavioural contraception
When a couple avoids having unprotected sex during the fertile phase of the woman’s menstrual cycle by tracking with the calendar, her body temperature and cervical mucus. Prevents fertilisation as the sperm will not meet an ovum during the infertile phases.

Question 33

Is the rhythm method for birth control free or not free?

Answer 33

Free

Question 34

What is the percentage of success in preventing pregnancy for the rhythm method?

Answer 34

Low success in preventing pregnancy (75-91%) success

Question 35

What are the disadvantageous of the rhythm method?

Answer 35

Low success in preventing pregnancy
Does not protect against STIs
Difficult to adhere to, requires discipline and cooperation from both partners.

Question 36

What is condom?

Answer 36

It is a barrier contraception. It forms a barrier to prevents sperm from entering the vagina as it can’t pass through the material and thus prevents fertilisation.

Question 37

What are the two types of condom?

Answer 37

Male: Thin rubber/plastic tube that covers the erect penis before sex. (Small teat to deposit semen)

Female: Femidom
Plastic tube with flexible ring at each end that is placed in the vagina before sex.
(One open end and close end)

Question 38

What are the advantageous of condom?

Answer 38

Apart from its main purpose, it is relatively cheap and protects against STIs.

Question 39

What are the disadvantageous of condom?

Answer 39

It is single-use. There is a moderate success in preventing pregnancy (82-98%) Possible allergies and requires cooperation from both partners.

Question 40

Which of the following can pass through the placenta?
A nicotine (yes), white blood cells (yes), gonorrhoea bacteria (yes)
B nicotine (yes), white blood cells (yes), gonorrhoea bacteria (no)
C nicotine (yes), white blood cells (no), gonorrhoea bacteria (no)
D nicotine (no), white blood cells (yes), gonorrhoea bacteria (yes)

Answer 40

C
Although nicotine is not taught, you can look at the gonorrhoea bacteria and the white blood cells to get the answer. White blood cells cannot pass through the placenta since there is no direct blood contact.

Question 41

If the menstrual cycle is 23 days, state when the implantation day(s) is/are?

Answer 41

24 to 28 day is the implantation
This is because 23-14(luteal)=9(ovulation)
Fertilisation - ovum survives for 2 days after ovulation.
Either 2 days or on that day so fertilisation is either 6 or 11
Implantation is 5-7 days after fertilisation, thus it is 11 to 18