Page 144 - Knowledge Organiser Yr7 24-25

2. Fertilisation
2.5
How does a fertilised egg develop into a foetus?
• The fertilised egg divides several times to form an embryo
• The embryo attaches to the lining of the uterus and develops into a foetus
2.6
What is the purpose of contraception?
To prevent pregnancy occurring
2.7
Name three ways contraception can work
1. Preventing the sperm meeting the egg
2. Stopping egg production
3. Stopping the fertilised egg implanting into the lining
of the uterus
2.8
Name two methods of contraception
1. Condom
2. Contraceptive pill
4. Menstrual Cycle
4.1
What is the menstrual cycle?
A recurring process that occurs in females to prepare an egg for fertilisation
4.2
When does the menstrual cycle begin in females?
During puberty (which will cause periods to begin)
4.3
On average, how long does the menstrual cycle take?
28 days
4.4 What controls the menstrual cycle? Reproductive hormones
4.5
What is menstrual bleeding?
When blood from the lining of
the uterus leaves the body through the vagina
4.6
What is ovulation?
The release of an egg from the ovaries
4.7
What are the main events that occur in the menstrual cycle?
1. Lining of the uterus builds up in preparation for a fertilised egg
2. Ovulation
3. Break down of the uterus lining (if fertilisation does not occur)
3. Adolescence
3.1
What is puberty?
The physical changes to the body that occur during adolescence
3.2
Where are sex hormones that cause puberty produced?
Females – in the ovaries Males – in the testes
3.3
What is the purpose of puberty?
To cause the reproductive system to develop which allows reproduction to occur as an adult
3.4
State four changes that takes place in both males and females during adolescence
1. Pubic hair and underarm hair grows 2. Body smell becomes stronger
3. Experience emotional changes
4. Growth spurt
3.5
State four changes that take place during
1. Breasts develop
2. Ovaries start to release egg cells 3. Periods start
4. Hips widen
3.6
State four changes that take place during
1. Voice breaks
2. Testes and penis get bigger
3. Testes start to produce sperm
4. Hair grows on the face and chest
5. Gestation and Birth
5.1
What is gestation?
The time from fertilisation until birth (pregnancy)
5.2
What is the gestation period in humans?
9 months (40 weeks)
Questions 2.4 and 2.5 should be revisited here
5.3
How is the growth of the foetus supported during gestation?
The foetus receives nutrients and oxygen from it’s mother through the blood
5.4
What is the function of the placenta in gestation?
To allow substances to pass between the mother’s blood and the foetus’ blood
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Knowledge Base: Science 7.11 Reproduction Year 7