BIOLOGY FORM TWO TOPIC 3: BALANCE OF NATURE

TOPIC 3: BALANCE OF NATURE

The Natural Environment

The Concept of Natural Environment

Explain the concept of natural environment

Natural environment is made up of all living and non living things that occur naturally on earth. An organism living anywhere in any environment is affected by the things around it such as air, water, animals, plants, microorganism, stones, rock, soil, clouds and the sun. everything around it in fact makes its natural environment. It is important to understand that the environment includes all living things as well as non living things.

IMPORTANT TERMS

1. Ecology: is the branch of biology that deals with studying interaction oforganisms with their environment
2. Population: is the total number of organisms of the same species living in a certain area. Example the number of frogs in a pond
3. Community: this refers to the sum of total of all population of different organisms living in a specific called habitat
4. Habitat: is the specific area where an organism is found and adopted. i.e it is an appropriate for the certain community example an ocean, grassland, and a pond
5. Ecosystem: refers to a natural unit made up of living and non living things whose interaction

Biotic and Abiotic Components of the Environment

Describe biotic and abiotic components of the environment

There are two components of environment,;

1. Biotic (living things)
2. Abiotic (non living things)

BIOTIC COMPONENT

These are living components in the environment such as animals, plants, fungi, and microorganisms. These organisms interact together in number of ways and these ways of interaction include the following;

1. Competition That organisms must compete for limited resources in struggle for life. For an organism to survive in an ecosystem it must compete with partner for the limited resources.
2. Predation Is the system in which one organism utilize the other as food. The eater is a predator while the eaten is a prey and a number of predators and preys regulate each other
3. Symbiotic relationship This is where there is a close relationship or association between organisms this association could take various forms like mutualism, commensalism, and parasitism
4. Adaptation Adaptation has enabled organisms to survive. They may be anatomically structurally physiologically or behavioural. Eg some organisms are poisoners to their predator while others while others develop warming colouration

ABIOTIC COMPONENTS

These include non living organisms that are found in ecosystem. Example air solar, energy, soil, and nutrients. Generally abiotic components of an ecosystem consist of physical environment and they are as follows.

1. Climatic factor Several change of climatic condition influence or determine the survival of organisms in ecosystem such condition include temperature, humidity, pressure etc
2. Aquatic condition Changes in the aquatic environment and the nature of environment it is self determined by the type of organism found in the area such a changes include water current, wave action, salinity, etc
3. Light condition factor These affect much plant population where photosynthetic process depend on the availability of light.
4. Soil factor/condition. These are also adaphic factors and they include soil texture, soil structure and soil PH

The Importance of the Natural Environment

Explain the importance of the natural environment

IMPORTANCE OF NATURAL ENVIRONMENT

1. It is a source of food to organisms
2. It provides shelter and security for organisms
3. It allow living and non living things to interact
4. It provides an appropriate setting for organisms to reproduce and increase in number.

Interactive of Organisms in the Environment

Ways in Which Living Organisms Interact with the Non Living Component of the Environment

Identify ways in which living organisms interact with the non living component of the environment

The following are the interaction of organism in the environment

1. Ground water and water from rain flow into streams and rivers
2. The stream and rivers flow into lakes and ocean
3. Water evaporate into the atmosphere from lakes and ocean and from plants through transpiration
4. The evaporated water precipitates to form water vapor which condenses to form clouds
5. Wind causes clouds to move for example from above the ocean to above the land
6. Rain fall and absorbed by plants or form grounds water, and the cycle begins again..

The Interaction of Organisms among Themselves

Explain the interaction of organisms among themselves

INTERACTION AMONG LIVING ORGANISMS

1. CompetitionThat organisms must compete for limited resources in struggle for life. For an organism to survive in an ecosystem it must compete with partner for the limited resources .EXAMPLE lions and leopards both hunt zebra, and so they are competitors
2. PredationIs the system in which one organism utilize the other as food. The eater is apredator while the eaten is a prey and a number of predators and preysregulate each other. e,g cats eat mice
3. SymbiosisThis is where there is a close relationship or association between organisms this association could take various forms like mutualism, commensalism, and parasitism
4. Mutualism is a relationship where two organisms benefit each other for example the rhizobium bacteria in the root nodules of legumes fix nitrogen into nitrate to ne used by the plant
5. AdaptationAdaptation has enabled organisms to survive. They may be an atomically structurally physiologically or behavioural. Eg some organisms are poisoners to their predator while others while others develop warming coloration
6. Commensalism is the interaction that is beneficial to one organism and is neutral to the other organism. For example when a bird builds a hole or a nest in a tree
7. Parasitism is the association where one organism benefit while the other is harmed. E.g plasmodium that cause malaria to human

Food Chain and Food Web

The Meaning of Food Chain and Food Web

Explain the meaning of food chain and food web

FOOD CHAIN

Is the sequence of living things in which each organism is the food of the next in thesequence.

1. 1. Grass →Zebra→Lion
2. Maize plant→grasshoppe→rFrog

→

FOOD WEB

Is made of interconnecting food chains

The Components of a Food Chain and Food Web

Mention the components of a food chain and food web

Producers

Are organism that can manufacture their own food for example green plants and green bacteria

Primary consumers

They are organisms that feed on producers for example rabbits, buffalo andsheep

Secondary consumer

They are organisms that feed on primary consumer

Decomposers

These organisms feed on dead matter and break it down thereby facilitating decomposition. For example bacteria and fungi

The Difference between Food Chain and Food Web

Distinguish food chain from food web

Differences between food chain and food web

Food chain	Food web
1. It consists of the single straight pathwaythrough which food energy travels in an ecosystem	1. It consists of a number of inter connected food chains through which energy travels in an ecosystem
2. Usually members of the higher trophic level feed upon a single type of organisms of lower trophic level	2. Usually members of the higher trophic level feed upon many organisms of lower trophic level
3. Isolated or separate food chainsincreases the instability of the ecosystem	3. Presence of complex food websincreases the stability of the ecosystem
4. It does not have any effect on improving the adaptability and competitiveness of the organisms	4. More complex food webs improves the adaptability and competitiveness of the organisms

Diagrammatic Representation of a Food Chain and Food Web

Construct a diagrammatic representation of a food chain and food web

Food chain

Food chain example

1. Grass →cow→human being
2. Phytoplankton→fish→bird

Food web

The Significance of Food Chain and Food Web in Real Life Situation

Explain the significance of food chain and food web in real life situation

The following are the significant of food chain and food web

1. Food chains and webs help in the flow of energy from producers to consumers and from one trophic level to another, without which energy flow would be impossible.
2. Food chain studies have had an important role in ecotoxicology studies tracing path ways and biomagnifications of environmental contaminants.
3. Learning how the food chain works enable us to understand the importance living organisms that make up the food chain and how the ecology is balanced. This is crucial since any interruption in food chain could lead to ecosystem imbalance.
4. Food chains and webs show the flow of energy through an ecosystem.
5. Understanding the effect of polluting the natural environment enable us to avoid or control environmental pollution so as to maintain natural ecosystems.
6. READ TOPIC 4
   

...