Life Processes
1. What are Life Processes? (5 Marks)
Life processes are the various biological activities performed by living organisms to maintain their
survival.
Some important life processes include:
1. Nutrition - The process of obtaining and utilizing food for energy.
2. Respiration - The breakdown of food in cells to form energy in the form of ATP.
3. Transportation - The movement of nutrients, gases, and other substances.
4. Excretion - The removal of metabolic waste products like carbon dioxide, urea, and excess water
from the body.
5. Reproduction - The process of producing new organisms to ensure species survival.
2. What is Nutrition?
Nutrition is the process of taking in and utilizing food.
It involves the breakdown of nutrients into smaller molecules and their absorption.
Types of Nutrition:
- Autotrophic Nutrition: Self-nourishment (e.g., plants).
- Heterotrophic Nutrition: Obtaining food from other organisms (includes saprophytic, parasitic, and
holozoic nutrition).
3. Autotrophic Nutrition
There are two types of autotrophic nutrition:
- Photoautotrophic Nutrition: Organisms use light energy to prepare food from simple inorganic
materials like CO2 and H2O.
- Photosynthesis is the process by which autotrophs prepare their own food. It occurs in
chloroplast-containing cells using sunlight.
General Reaction of Photosynthesis:
6CO2 + 6H2O -> C6H12O6 + 6O2 (Sunlight, Chlorophyll)