KS3 Reproduction

Front

What carries oxygen and nutrients to the foetus?

Back

Umbilical cord

Answer explanation

The placenta exchanges oxygen and nutrients between the mother's and foetus' blood. The umbilical cord connects the foetus to the placenta and carries substances back and forth.

Front

What is the main function (job) of the testes?

Back

Making sperm

Answer explanation

The main job of the testes is to make sperm. Their secondary job is to make hormones. The main job of the ovaries is to make ova.

Front

What releases an ovum (egg cell) during ovulation?

Back

Ovary

Answer explanation

The egg cells mature in the ovary one at a time and then get released every month. They are released into the fallopian tubes, but aren't made there.

Front

In which development stage do a baby's organs begin to form?

Back

Embryo

Answer explanation

Most organs do not finish forming until the end of the foetus stage, especially the lungs. However, vital organs like the heart begin to form from the embryo stage.

Front

Which chromosome combination shows a person is male?

Back

XY

Answer explanation

Sex chromosomes can be XX or XY only.

Females have XX and males have XY.

Front

Name the process where an egg cell nucleus fuses with a sperm cell nucleus.

Back

Fertilisation

Front

Which term describes a developing human from conception to the eighth week of pregnancy?

Back

Embryo

Front

What is the main purpose of sexual reproduction?

Back

Create genetic variation in offspring

Answer explanation

Asexual reproduction can be used for making more cells for growth and repair or for making an identical offspring (clone).

Sexual reproduction is used for creating variation in offspring to increase the chances that one will survive to adulthood.

Front

In plants, which structure produces pollen grains containing male gametes?

Back

Anther

Front

Main factor determining which traits are passed to the next generation?

Back

Environmental pressure

Answer explanation

Random chance will determine if an offspring will receive a beneficial trait (adaptation) from its parents or not, BUT the parents cannot pass on any traits if they cannot survive in their environment. So, environmental pressure determines which parents can survive to pass on their traits.