Nutrient Cycles, Food chains and Food Web
Subject :
Basic Science and Technology
TERM
FIRST TERM
Week 4
CLASS
JSS 2 / Basic 8
Topic :
Nutrient Cycles, Food chains and Food Web
Instructional Materials :
- Diagrams of food chain
- Grasses, model of animals in the food web
- Pictures showing animals in food web
- Textbooks
- Workbooks
- Online Materials
Reference Materials
- Scheme of Work
- Online Information
- Textbooks
- Workbooks
- 9 Year Basic Education Curriculum
Previous Knowledge :
The pupils have been taught
Relationship between organisms in their habitat
in their previous lesson
Behavioural Objectives : At the end of the lesson, the learners will be able to
- Explain food circles
- Describe food chain
- Say the meaning of food web
- Say the major importance of this chain relationship between organisms
CONTENT
1. Meaning of Nutrient Cycle in Nature
2. The Water Cycle
3. Nitrogen Cycle
4. Carbon Cycle
5. Food Chain
6. Food Web
Meaning of Nutrient Cycle in Nature
A nutrient cycle is a repeated circular form of a particular nutrient or element from the environment through one or more organisms and back to the environment. This Nutrient cycle is necessary for the continued existence of some living organisms so that they will not go into extinction. The organisms that are involved in the nutrient circle benefit from the other organisms in the circle that they feed or depend on. The circle is created by nature in such a way that some organisms are the primary producers, which other organisms feed on. Some creatures are scavengers and clean up remnants in the ecosystem. Sun is the major supplier of solar energy in the ecosystem.
Examples of Other Circles in the Ecosystem
Nutrient circle is the constant circulations of nutrients around the ecosystem. Photosynthesis and respiration drive the movement of oxygen and carbon dioxides to become available all the times.
Water cycle.
We use water every day, where does water comes from, water is found almost everywhere in different forms. Water cycle is the continuous movement of water, from land, rivers and oceans to the atmosphere as vapour and from atmosphere back to land and rivers or oceans as rain.
Nitrogen cycle
We eat food rich in protein such as beans, how does the protein content in it forms? The basic chemical in protein is nitrogen compounds. Nitrogen cycle is the constant flow and replacement of nitrogen in the atmosphere and land and how it gets to plants and animals and back to the soil or atmosphere
Carbon cycle
One of the most abundant elements in the environment is carbon. It exists in the atmosphere as carbon iv oxides (CO₂). Carbon cycle is the processes by which plants and animals use carbon iv oxide and return it back to the atmosphere. Plants absorbs CO₂ from the atmosphere during photosynthesis and releases it back during respiration. Animals takes in carbon stored in plants as food and release it out during respiration. Carbon is also released into the atmosphere through the burning of fossil fuel.
Nutrient cycles in the ecosystem
The nutrient cycle is a system where energy and matter flow between living organisms and non-living parts of the environment. This occurs as animals and plants consume, depend or feed on other creatures as nutrients , and these nutrients are then released back into the environment via death and decomposition.
Importance of Nutrient Circles
- It makes it possible for energy and matter to be transfered between organisms
- It maintains the continued existence of living organisms
- It balance the ecosystem
- Nutrient circle makes it possible to change one form of energy to another
- It is a form of storage of elements, nutrients or energy until they will finally be needed
Food chain
Food chain is the inter connection among organisms in the ecosystem as they depend on each other for survival in respect of food and energy transfer.
For example
Sun aids the growth of carrot.
The carrot is eaten by the rabbit
Rabbit is eaten by fox
And the trend continues like that.
Food Web
This is a more complex food relationship among living organisms. It’s just like the spider web, just as the name implies.
Food web is a diagram that shows the multiple connections between the primary producers and consumers in an ecosystem.
For instant, if the habitat of the organisms in terrestrial, then we know that sun is the major supplier of solar energy in the ecosystem.
The green plants like grasses produce their own food in the presence of sunlight. The process whereby green plants manufacture their food in the presence of sunlight is known as photosynthesis.
In the food web, animals like goats, rams, sheep or donkeys feed on the green plants like grasses.
Or at times the green plants may serve as food for insects like crickets, locusts or grasshoppers. That is why it is called food web. Everything in respect of food connection is interwoven and connected just like the spider’s web.
Lizards feed on locusts and spiders
Lizards serves as food for birds like eagles or hawks
Man feed on sheep and goats
Man dies and bacteria helps in decomposition
Presentation
The topic is presented step by step
Step 1:
The class teacher revises the previous topics
Step 2.
He introduces the new topic
Step 3:
The class teacher allows the pupils to give their own examples and he corrects them when the needs arise
EVALUATION
- The roles of bacteria in the nutrient Circle is to help with the _______ of Organisms (à) resurrection (b) decomposition (c) purification
- Burning of bush affect the _______ circle of the atmosphere (a) water (b) carbon (c) sun
- A pathway by which nutrients pass from one stage in form or organism to another stage is known as _____________ (a) Photosynthesis (b) caffeinated (c) nutrient Circle
- Write out four importance of food chain
Conclusion :
The class teacher wraps up or conclude the lesson by giving out short note to summarize the topic that he or she has just taught.
The class teacher also goes round to make sure that the notes are well copied or well written by the learners.
He or she does the necessary corrections when and where the needs arise.
