Y8 Biology - Human Reproduction

What is Puberty?

When a child's body develops into an adult's body

What are Hormones?

Chemical messengers that travel through the bloodstream.

What is Testosterone?

The male sex hormone that triggers sperm production and controls the male secondary sexual characteristics.

Where is testosterone produced?

In the testes.

What is Oestrogen?

The female sex hormone that starts periods and controls the female secondary sexual characteristics.

What are the sexual characteristics that only occur in Males?

Voice breaks, facial hair grows, body becomes more muscular, Testes produce sperm cells etc.

What are the sexual characteristics that only occur in females?

Voice deepens, hipes widen, breasts develop, periods occur etc.

What are the sexual characteristics that occur in both Males and Females?

Pubic and underarm hair grows, sexual organs grow and develop, etc.

What are the Testes?

Where sperm cells are made.

What is the Scrotum?

Skin that holds the testes.

What are the Sperm ducts?

Tubes that carry sperm from testes to the urethra.

What are the functions of Glands (Prostate)?

They add nutrients and fluid to the sperm cells to produce semen.

What is the Urethra?

A tube that carries either urine or semen out of the body through the penis.

What is the Penis?

The organ that enters the vagina during sexual intercourse.

What is the Foreskin?

Skin that protects the end of the penis.

What is the Ovary?

Where eggs are produced and where they mature for release each month.

What is the Oviduct (fallopian tube)?

Small tube that leads from each ovary to the uterus and is where fertilisation occurs.

What is the Uterus lining?

The wall of the uterus.

What is the Cervix?

A ring of tissue separating the uterus and the vagina

What is the Vagina?

The organ that is entered by the penis during sexual intercourse and is also part of the birth canal

What is the Menstural Cycle?

It is a cycle that prepares the female body for possible pregnancy each month.

What is another name for the Menstural Cycle?

A Period

What happens from Day 1-5 in the Menstural Cycle?

Uterus lining breaks down -mensturation occurs.

What happens from Day 6-13 in the Menstural Cycle?

Uterus lining builds up.

What happens on Day 14 in the Menstural Cycle?

Egg is released from the ovary and travels down the oviduct - Ovulation occurs.

What happens from Day 15-28 in the Menstural Cycle?

Uterus lining is maintained.

What are the 2 key hormones which regulate the menstrual cycle?

Oestrogen and Progesterone.

What is the role of Oestrogen in the menstrual cycle?

It repairs and thickens the uterus lining, with levels increasing just before ovulation.

What is the role of Progesterone in the menstrual cycle?

Maintains the Uterus lining for a potential pregnancy after ovulation.

If fertilisation happens, how do the levels of Progesterone change?

Levels remain high with no period happening

If fertilisation doesn't happen, how do the levels of Progesterone change?

Levels will drop, and a period will follow.

What is the Male sex cell?

A sperm cell.

How is the Male sex cell adapted?

Its streamlined head contains enzymes for penetrating the egg, its tail helps it swim, its middle piece provides energy and its nucleus contains the father's DNA.

What is the Female sex cell?

An egg cell (ovum).

How is the Female sex cell adapted?

Its cytoplasm contains food stores for the foetus, its cell membrane prevent further sperm from entering and its nucleus contains the father's DNA.

What is Fertilisation?

When a sperm cell and an egg cell fuse.

How does Fertilisation occur?

Sperm cells enters the Vagina, passes through the cervix, enters the oviduct and only 1 sperm breaks through the cell membrane and enters the ovum, head first - the fertilised ovum results in a zygote.

What happens after Fertilisation?

Zygote divides to make an embryo (ball of cells) and implants into the uterus walls - Implantation occurs.

After Implantation, what happens to the embryo?

It develops into a foetus.

What is the placenta?

A temporary organ that develops during pregnancy. It connects the developing baby to the uterine wall.

What is the placenta's role in pregnancy?

It brings foetal blood supply close to the mother's blood without mixing. It allows for nutrients to pass from mother's blood to foetal blood and for waste products pass from foetal blood to mother's blood.

How can some toxins affect the foetus?

Nicotine or pathogens can cross the placenta from the mother's blood and get transfered to the foetus.

What is the Umbilical Cord?

A flexible, tube-like structure that connects a developing fetus to the mother during pregnancy.

What is the Umbilical Cord's role in pregnancy?

It connects the foetus to the mother and carries foetal blood to and from the placenta.

What is the Amniotic Sac?

A fluid filled cavity that surrounds the foetus, protecting it.

What is the role of the Amniotic Sac during pregnancy?

It protects the foetus from injury and also helps to regulate the temperature of the foetus.

What is the Amniotic Fluid?

The fluid that fills the amnionic sac, surrounding the foetus.

What is the role of the Amniotic Fluid during pregnancy?

It keeps the foetus moist to prevent drying, acts as a water cushion to support the foetus; allowing it to move freely, absorb shock and to lubricate the vagina during birth

How does childbirth begin?

With small contractions of the uterus wall, which gradually become stronger and more frequent.

How does a mother's water break?

Eventually the contractions cause the amniotic sac to break and the fluid escapes.

Why does the cervix dilate?

So the baby can be pushed out of the vagina easily.

What happen's after the baby is delivered?

The placenta breaks away from the uterus wall and is also delivered and the umbilical cord it cut and tied.

What are Identical Twins?

Offsprings that develop from a single fertilized egg that splits in two, creating two genetically identical organisms, having the same sex and have very similar physical characteristics

What are Fraternal Twins

Offsprings that develop from two separate eggs that are fertilized by two different sperm during the same pregnancy, sharing roughly 50% of their genes.

How are babies fed?

By either bottles or their mother's breast.

What are the advantages of breast feeding?

It is good for both babies and mothers as it gives babies the best nutrition and protects them from illness and for mothers, it helps recovery and builds a strong bond with the baby.

What are the advantages of bottle feeding?

It is flexible and convenient as it lets others help feed the baby, gives the mother more freedom, and makes it easy to track how much milk the baby drinks.

What are some disadvantages of breast feeding?

It can be uncomfortable, takes time, and requires the mother to avoid certain substances. Some women may have trouble producing milk, and it can be socially challenging.

What are some disadvantages of bottle feeding?

It can be costly and doesn't provide natural antibodies. Some babies may also have digestion problems with formula.