4. Nutrition in Living Organisms

• Herbivores: Cow, deer, goat, buffalo
• Carnivores: Tiger, lion, frog
• Omnivores: Human, sparrow, cockroach
• Scavenger: Vulture
• Decomposers: Bacteria, fungus
• Parasite: Tick

Living organisms need nutrition:

• to get energy for work and life processes;
• for growth and development of the body;
• to repair damaged cells;
• to fight diseases.

Green plants make their own food. This process is called photosynthesis.

1. Roots absorb water and minerals. The stem carries them to the leaves.
2. Leaves take in carbon dioxide from air through stomata.
3. Chlorophyll in the leaves absorbs sunlight.
4. With this energy, carbon dioxide and water form food (glucose). Oxygen is given out.
5. The food is carried to all parts of the plant.

Plants that grow on other plants and get food from them are called parasitic plants. They are of two types:

• Complete parasites: They have no chlorophyll. They take all their food from the host. Example: Cuscuta (dodder).
• Partial parasites: They make their own food. They take only water and minerals from the host. Example: Loranthus.

1. Ingestion: Taking food into the body.
2. Digestion: Breaking food into simple, soluble forms.
3. Absorption: Passing of digested food into the blood.
4. Assimilation: Use of absorbed food by the cells.
5. Egestion: Removal of undigested food from the body.

Amoeba, Euglena, Paramoecium, bacteria, yeast

Insectivorous plants grow in soil that lacks nitrogen. They get nitrogen by eating insects. To catch insects, they must attract them. Their bright colours attract insects. So insectivorous plants are attractively coloured.

Butterflies feed on nectar. Nectar is found deep inside flowers. The long proboscis reaches deep into the flower. It sucks the nectar like a straw. So butterflies have a long, tube-like proboscis.

No, we are heterotrophs. Autotrophs make food from carbon dioxide and water using sunlight. We cannot do this. We only cook food that we get from plants and animals.

Heterotrophs are greater in number. All animals, fungi and most bacteria are heterotrophs. Autotrophs are mainly green plants. One plant feeds many heterotrophs.

Heterotrophs depend on plants for food. In deserts, water is scarce. So very few plants grow there. Less food means fewer heterotrophs. The sea has plenty of water and algae. They provide a lot of food. So heterotrophs are found in large numbers in the sea.

• Ectoparasites like lice and ticks suck blood. They cause itching and weakness. Some spread diseases.
• Endoparasites like tapeworm and roundworm live in the intestine. They take away digested food. This causes weakness, stomach pain and malnutrition.

Food is made by photosynthesis. It needs chlorophyll. Chlorophyll is present only in the green parts. Other parts have no chlorophyll. So food is made only in the green parts.

Sample observation – a mango tree:

• Caterpillars eat its leaves. Sparrows and lizards eat the caterpillars.
• Aphids suck its sap. Ladybird beetles eat the aphids.
• Bees and butterflies suck nectar from its flowers. Spiders and birds eat them.
• Parrots and squirrels eat its fruits. Snakes and owls eat them.
• Loranthus grows on its branches. Fungi grow on its fallen leaves.

1. Title slide with your name and class.
2. What is nutrition? Need for nutrition.
3. Photosynthesis with a diagram.
4. Parasitic, insectivorous, saprophytic and symbiotic plants.
5. Steps of nutrition in animals.
6. Types of nutrition in animals.
7. Flowchart and conclusion.

Add pictures and keep the text short.