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BIOLOGY FROM 1

Chapter 5: habitat of living organisms

Environmental factors affecting plants and animals

Many factors affect living organisms and they can be grouped into; Biotic (living factors) and Abiotic factors (non-living factors).

  1. The abiotic factors:

   It is the form of non living part of the habitat e.g. sunlight, water, wind etc.

Effects of sunlight

  1. On plant;
  • It is needed for photosynthesis needed for the manufacturing of chlorophyll in plants
  • It influences plant growth
  1. On animals;
  • Important in the production of vitamin D in humans on their skin
  • Enables animals to see during the day
  • Help in the production of melanin which protects us from ultra-violet light

Effect of water

  1. On plant;
  • It is needed for seed germination
  • It is also needed for photosynthesis
  • Help in fruit and seed dispersal
  1. On animals;
  • Provides a habitat for many aquatic animals like fishes
  • Important for digestion in man
  • Forms part of blood

Effect of wind

  1.  On plant
  • Helps in the dispersal of seed and fruits
  • It increases the rate of transpiration in plant
  • It helps in wind pollination of plants
  1. On animals
  • It increases the rate of evaporation of sweat from the body, thereby producing a cooling effect
  • Strong winds may destroy houses making people homeless

Effect of temperature

  1. On plants
  • High temperature increases the rate of fruit ripening
  • Low temperature causes poor growth in plants
  • Increases the rate of photosynthesis
  1. On animals
  • Low temperature causes some animals to hibernate
  • High temperature causes sweat in man
  • Low temperatures cause hypothermia in animals

Effect of day and night

  1. On animals
  • Some animals are active only during the day. They are called diurnal animals e.g. honey bees, humans, cows etc.
  • Some animals are only active at night. They are called nocturnal animals e.g. bats, owl, crickets etc.
  • Most animals hunt in the day
  1. On plant
  • Plants carry out photosynthesis during the dat when sunlight is available
  • Most plants open their stomata during the day and close at night
  1. The biotic factors

These factors concern the living organisms in a habitat and how they affect each other. Living organisms in a habitat interact in many ways, some depend on others for food and shelter, some are harmful to the community and others useful.

 

par Claude Foumtum