Topic 12 - Reproduction Flashcards
(38 cards)
what is puberty?
Puberty is the stage in life when a child’s body develops into an adult’s body. The changes take place gradually, usually between the ages of 10 and 16, but sometimes before or after this age.
What is a hormone?
A hormone is a chemical substance, produced by a gland and carried by the blood
What are the 2 types of hormones? (2)
- Testerone
- Oestrogen
What is testerone?
a hormone produced by the testes which controls the development of male secondary sexual characteristics, for example, facial hair
What is oestrogen?
a hormone produced by the ovaries which controls the development of female secondary sexual characteristics, for example breast development
Changes in puberty - both (3)
- Pubic hair grows
- Underarm hair grows
- Sexual organs grow and develop
Changes in puberty - boys only (4)
- Voice breaks
- Hair grows on face and body
- Body becomes more muscular 4. Testes start to produce sperm cells
Changes in puberty - girls only (4)
- Voice deepens gradually
- Hips get wider
- Breasts develop
- Ovaries start to release egg cells - menstruation starts
What is menstrual cycle?
The menstrual cycle is a recurring process that occurs in females after puberty. It takes place in cycles which last around 28 days.
What happens during the menstrual cycle?
During the cycle, the lining of the
uterus is prepared for pregnancy. If implantation of a fertilised egg into the uterus lining does not happen, the lining is then shed. This is known as menstruation.
When a woman is pregnant what happens to the placenta?
If a woman becomes pregnant, the
placenta produces progesterone. This maintains the lining of the uterus during pregnancy and means that menstruation does not happen.
Where is oestrogen produced and what is the role of it?
Ovaries
Repairs, thickens and maintains the uterus lining.
Where is progesterone produced and what is the role of it?
Ovaries
Maintains the lining of the uterus during the middle part of the menstrual cycle and during pregnancy.
The role of placenta in the nutrients of a developing embryo? (2)
- Oxygen and nutrients such as glucose diffuse across the placenta from the mother to the fetus.
- Carbon dioxide and other waste substances diffuse across the placenta from the fetus to the mother.
How is the embryo protected by the amniotic fluid?
Amniotic fluid surrounds the embryo inside the amnion, cushioning and protecting the developing embryo.
What is asexual reproduction?
Asexual reproduction does not involve sex cells or fertilisation
What is sexual reproduction?
Sexual reproduction allows some of the genetic information from each parent to mix, producing offspring that resemble their parents
What is fertilization?
In sexual reproduction new organisms are produced from the fusion of a male sex cell with a female sex cell. This fusion of gametes is called fertilisation.
What and where are male gametes produced?
Male gametes are called
sperm cells. They are continuously produced in the testes
What and where are female gametes produced?
Female gametes are called egg cells and are produced in the ovaries of the female mammal.
What happens during intercourse?
During sexual intercourse sperm cells travel through the sperm duct, into the urethra and are released out of the end of the penis into the cervix and travel through the uterus into the fallopian tubes to fertilize with a female gamete.
When the male and female gametes fuse what happenes?
zygote is produced containing the full 46 chromosomes, half of which came from the father and half from the mother.
How many chromosomes are produced in each gamete?
each gamete contains 23 chromosomes
What is the zygote?
The zygote divides to form two new cells, which then continue to divide many times. Many of the new cells produced become specialised to perform particular functions and form all the body tissues of the new individual.
