Interdependence of Life, Food Chains and Food Webs
Learn how living and non-living components of the environment interact, how food chains and food webs are formed, and why interdependence is essential for maintaining balance in ecosystems.
Introduction
Interdependence is the relationship where living organisms depend on each other for survival. In any natural environment, no organism lives completely on its own. Instead, living things interact with other organisms and with the non-living components around them in order to obtain what they need to survive.
These interactions are essential for the functioning of ecosystems. Organisms depend on one another for many important processes such as obtaining food, reproduction, protection, and maintaining environmental balance.
For example, animals depend on plants for food and oxygen, while plants depend on animals and insects for pollination and seed dispersal. In addition, organisms depend on non-living factors such as water, sunlight, air, and soil nutrients.
Examples of things organisms depend on include:
- Food
- Shelter
- Protection
- Pollination
- Seed dispersal
Because of these interactions, living and non-living components form a network of relationships that helps maintain balance and stability within ecosystems.
2.4.1 Biotic and Abiotic Factors of the Environment
The environment consists of everything that surrounds living organisms and influences their survival. These components can be grouped into two main categories: biotic components and abiotic components.
1. Biotic Components
Biotic components are the living parts of the environment. These include all organisms that grow, reproduce, and interact with other living things.
Examples:- Plants
- Animals
- Humans
- Microorganisms such as bacteria and fungi
💡 Did You Know?
Earthworms are important biotic components in soil ecosystems. As they move through soil, they mix organic matter and improve soil fertility, helping plants grow better.
Biotic components interact with each other through feeding relationships, competition for resources, and cooperative relationships such as pollination and symbiosis.
Examples of interactions:- Herbivores feed on plants
- Carnivores feed on herbivores
- Decomposers break down dead organisms and recycle nutrients
1. Abiotic Components
Abiotic components are the non-living parts of the environment that influence the survival and distribution of living organisms.
Examples include:- Water
- Temperature
- Wind
- Humidity
- Light
- Atmospheric pressure
- Soil pH
- Salinity
Living organisms depend on abiotic factors for survival and growth. For example, plants require sunlight for photosynthesis, animals require oxygen for respiration, and all organisms require water for metabolic processes.
Interrelationships Between Living Organisms
Living organisms interact with each other as they compete for limited resources necessary for survival.
These resources include:- Food
- Water
- Space
- Shelter
- Predation
- Competition
- Parasitism
- Symbiosis
- Saprophytism
a) Predation
Predation is a relationship where one organism kills another organism for food.
- Predator – the organism that hunts
- Prey – the organism that is eaten
- Lion hunting antelope
- Owl catching mice
- Birds feeding on insects
💡 Did You Know?
Some predators hunt using special biological tools. For example, bats use echolocation to locate insects in the dark, while snakes detect heat from their prey using special heat-sensing organs.
Importance of Predation
- Controls prey population
- Maintains ecological balance
- Provides food for predators
- Removes weak or sick individuals
Adaptations of Predators
- Sharp claws
- Sharp teeth
- Strong jaws
- Good eyesight
- Fast movement
- Venom in some species
Adaptations of Prey
- Camouflage
- High speed
- Protective structures such as shells or horns
- Living in groups
- Highly developed senses
b) Competition
Competition occurs when organisms struggle for the same limited resources in their environment.
Resources include:- Food
- Water
- Space
- Shelter
- Light
- Nutrients
Types of Competition
1. Intraspecific Competition – competition within the same species.
- Maize plants competing for nutrients
- Dogs fighting for food
- Male animals competing for mates
2. Interspecific Competition – competition between different species.
- Lions and leopards competing for prey
- Different plant species competing for sunlight
- Crops and weeds competing for nutrients
c) Parasitism
Parasitism is a relationship where one organism benefits while the other is harmed.
- Parasite – benefits
- Host – harmed
Types of Parasites
Ectoparasites:- Fleas
- Ticks
- Lice
- Tapeworms
- Roundworms
- Hookworms
d) Symbiosis
Symbiosis is a close relationship between organisms where at least one organism benefits.
Types:- Mutualism – both organisms benefit
- Commensalism – one benefits, the other unaffected
e) Saprophytism
Saprophytism is a feeding relationship where organisms obtain nutrients from dead and decaying matter.
Examples:- Mushrooms
- Yeast
- Moulds
- Bacteria
These organisms act as decomposers and recycle nutrients back into the environment.
Abiotic Factors Affecting Living Organisms
Abiotic factors influence the survival, growth, reproduction, and distribution of organisms.
Important abiotic factors:- Water
- Wind
- Light
- Salinity
- Temperature
- Atmospheric pressure
- pH
Effect of Water
- Supports plant growth
- Maintains animal body processes
- Improves crop production
Effect of Wind
- Disperses pollen and seeds
- Helps plant reproduction
- May cause soil erosion and crop damage
Effect of Light
- Enables photosynthesis
- Influences plant growth and flowering
- Affects animal behaviour patterns
Effect of Temperature
- Affects metabolism
- Influences reproduction
- Determines distribution of organisms
Effect of pH
- Controls nutrient availability in soil
- Affects plant growth
- Influences aquatic life distribution