T 1 T 5 Life cycles NATURAL SCIENCE Gr. 5

KEY WORDS Male part of a flower that produces pollen. Stamen Pistil Female part of a flower that produces seeds. Gender sign for male. Gender sign for female.

KEY WORDS Fine powder in flowers that help to produce seeds. Pollen Pollinators Animals that help with pollination for example bees and butterflies.

KEY WORDS The process plants use to produce seeds. Pollination Nectar A sweet juice produced by flowers that attract pollinators. Fertilisation To join particles of pollen so that a new plant can develop.

KEY WORDS Womb An organ inside the female body in which a baby grows. Gills Breathing organ of a fish.

Growth and development The life cycle of a plant or animal includes all the stages and processes that take place in the life of a plant or animal as it grows and develops. Death can occur at any life stage. It describes how one generation gives rise to the next generation through reproduction.

A plant life cycle Plant life cycle Sprouting seed

Seedling or young plant Ripe fruit Unripe fruit Flower Seeds Seedling or young plant Mature plant

Seedling or young plant Ripe fruit Unripe fruit Flower Seeds Seedling or young plant Mature plant

Pollen

Female part of the flower = Male part of the flower: Pistil Male part of the flower: Stamen

Stigma Pollen Pistil Stamen Ovule

____ Pollinators Pollen has to travel from the stamens of the male flowers to the pistils of the female flowers. Many flowers have both stamens and pistils, so pollination can take place easily. Some flowers have them on separate flowers. These flowers need pollinators to help them during fertilisation.

Pollen can be dispersed by wind, water, insects, birds and even mammals. We call these animals pollinators.

These animals are attracted by the colour, smell and taste of a flower’s nectar. Pollen sticks to them and is then carried to other flowers.

Name 2 abiotic factors that can disperse (spread) pollen. Class activity Name 2 abiotic factors that can disperse (spread) pollen. Wind Water Name 4 pollinators. Bees Butterflies Humming birds Bats

____ Fertilisation Flower reproduction Stamen Flower Pollen grains 4 3 1 5 2 6 8 7 10 9 Pistil Stamen Stamen Pollen grains Pollen grain lands on pistil Flower reproduction Flower New flower forming Pollen tube grows down through pistil Seed germinates to become a new seedling. Fertilised seed inside the fruit

____ Fertilisation Stamen Flower Flower Pollen grains Pistil Stamen New flower forming Pollen grain lands on pistil Flower Pollen tube grows down through pistil Flower Seed germinates to become a new seedling. Fertilised seed inside the fruit

Pollen rubs off onto the pistils. The pollen then grows down a small tube in the pistil until it reaches the egg cell at the bottom of the pistil. The egg cell is fertilised and becomes a seed. The seed is protected by a fruit.

____ Seed dispersal Seeds can be dispersed by wind, water, animals and by the plant itself. Some seeds are eaten and then dispersed through animal faeces. Some fruits burst open when they dry out, releasing the seeds into the air. Others have wing-like shapes that help them to glide through the air.

Seed dispersal

Animals Water Self Wind

____ Animal life cycle Not all animals take care of their young like humans do. Some mate, lay their eggs and die. Some baby animals look like their parents. While other baby animals have to go through a few processes to look like their parents.

Summary on the animal life cycle NS: Watch video on animal life cycles, topic 5. Make a summary of the video. Butterfly life cycle

Life cycle of a locust Adult male and female locusts mate. The eggs are fertilised inside the female. She then lays the eggs underground and covers them in a foam to keep them moist. When the eggs hatch, nymphs appear. Nymphs are small grasshoppers that look like their parents. After many stages of growing they become adults and the life cycle starts all over.

Adult female locust laying eggs 1. 2. 3. 4. Adult female locust laying eggs eggs nymph adult eggs

Adult female locust laying eggs 1. 2. 3. 4. Adult female locust laying eggs adult eggs eggs nymph

Life cycle of a frog Frogs live the first part of their life in water as tadpoles. Tadpoles breathe by absorbing water through its gills. The tadpole slowly grows legs and develops into an adult frog.

The adult frog can also absorb oxygen through its skin. The adult frog can breathe air through its lungs, we call this pulmonary breathing. The adult frog can also absorb oxygen through its skin. The adult frog can therefore live both in water and on land. Life cycle of a frog

Mature frogs mate. Eggs are laid and fertilized. Tadpoles develop in stages.

_____ Act 2. Arrange an animal life cycle NS: T1T5 Activity 2.

Life cycle of mammals Baby mammals are not born from eggs, they are born alive. The mother suckles and takes care of her young. The female animal carries egg cells and the male has sperm cells. The male mates with the female and places the sperm cells into the body of the female animal.

When the egg- and sperm cells come together, fertilisation has taken place. The female carries her baby in the womb. This is called pregnancy. The female mammal gives birth when the baby is fully developed.

The mother suckles her baby until it is old enough to feed. Eventually it grows into an adult, mates and the life cycle starts again. (See figure 6, topic 5.)

Act 2 MEMO, question 1 C D A E B

Act 2 MEMO, question 2 A D Grow C E B Baby Young animal Mature adult Male and Female D Baby A Grow E Young animal B Mature adult Mate Mature

HOMEWORK: NS: mind map T1T5.