Plants - Class 7 Science Revision Notes

• Interdependence
• Food Chain
• Crop Pest
  • Types of Pest
  • Crop pest and their Effects on Plant
  • Pest Control Measures

Interdependence

This is the dependence of one person on another;or one living thing upon another.

Plants depends on animals in the following ways:

• Carbon dioxide
• Pollination
• Animal waste
• Nutrients

Animals depends on plants in the following ways:

• Food
• Shelter
• Medicine
• Oxygen

Plants depends on other plants for the following ways:

• Support
• Shade
• Habitat

Animals depends on other animals in the following ways:

• Transport
• Food

Examples of Insectivorous plants

• Venus flytrap
• Cobra lily
• Sundew
• Bladderwort
• Butterwort
• Picher plant.

Food Chain.

A food chain is a relationship in which living things depends a feed on one another directly.

Examples of a food chain:

1. Grass   ---->    Grasshopper     ---->      Chicken          ---->        Hawk
   (Producer). (Primary cosumer).       (Secondary consumer).    (Tertiary consumer)
2. Algae---->Small fish----->Big fish---->King fish
   NB:Learners are always asked what happen if one group is exempted:
   Example:
   What will happen if all chicken died because of a disease kin the first example;
   
   • Grasshopper will increase since what feeds on them are dead
   • Grass will reduce since grasshoppers are more in number
   • Hawk will decrease since their food is not there

Crop Pest.

A pest is a troublesome or harmful thing,animal or insect.

They damage crops

Types of Pest

Pests are classified into two ie

1. Field Pests
   • cutworms
   • Aphids
   • Stalk borer
   • Weaver birds
2. Storage pests
   • Weevils
   • Termites
   • Rat
   • Mole

Crop Pest and their Effects on Plant

Pest Control Measures

• Scaring .
• Trapping .
• Hand picking.
• Weeding.
• Spraying.
• Prunning.