Grade 6 Science And Technology Living Things – Reproductive System Notes

Reproduction is the process by which living things produce new young ones (offspring). It makes sure plants and animals continue to exist.

• Asexual reproduction — one parent produces offspring. Offspring are usually identical to the parent.
• Sexual reproduction — two parents (male and female) combine special cells to make offspring. Offspring are not exactly the same as either parent.

• Bacteria — binary fission (one becomes two).
• Hydra — budding (a small Hydra grows on the parent then detaches).
• Starfish — regeneration (parts can grow into a new starfish).
• Plants — vegetative propagation: runners (strawberry), stem cuttings, tubers (Irish potatoes).

Many plants produce flowers. Flowers have male and female parts. Pollination moves pollen to the female part so a seed can form.

Kenyan examples: maize (corn) is mostly wind-pollinated; beans and flowers are pollinated by bees and other insects. When pollen reaches the ovule, fertilization makes seeds; seeds grow into new plants.

Animals make special sex cells called gametes. Male gamete = sperm. Female gamete = egg (ovum). When a sperm joins an egg (fertilization), a new animal begins to grow.

Fertilization can be external (e.g., many fish and frogs release eggs and sperm into water) or internal (e.g., humans, many land animals). After fertilization, the embryo grows into a baby animal.

Around the ages 10–14, boys and girls start going through puberty. This means their bodies change and they begin to be able to reproduce when older. Common changes include growth in height, hair growth, and start of menstruation (periods) for girls. It is important to talk to a parent, teacher or nurse if you have questions.

• To make new members of the species (so the species does not die out).
• To create diversity (especially in sexual reproduction), which helps animals and plants survive changes.

• Gamete — the sex cell (sperm or egg).
• Fertilization — joining of sperm and egg.
• Pollination — transfer of pollen from stamen to pistil.
• Seed — a plant baby that can grow into a new plant.
• Asexual and Sexual — types of reproduction.

1. Look at three plants at home or school. Which one shows insect pollination? How do you know?
2. Find an example of a plant that reproduces asexually (e.g., runners or cuttings). Draw it and label how the new plant starts.
3. Ask your teacher: name one animal with external fertilization and one with internal fertilization.

1. What is the difference between sexual and asexual reproduction?
2. Name the male gamete and the female gamete.
3. Give one example of pollination in Kenya.