Lesson Notes By Weeks and Term - Senior Secondary 2

TERM – 1^ST TERM

WEEK NINE

Class: Senior Secondary School 2

Age: 16 years

Duration: 40 minutes of 5 periods each

Date:

Subject: Biology

Topic: ECOLOGICAL MANAGEMENT: Tolerance

SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to

1. Differentiate between macro and micro decomposers
2. Identify the importance and roles of decomposers to man

iii. Describe maximum and minimum tolerance

INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers, demonstration, videos from source

INSTRUCTIONAL MATERIALS: Videos, loud speaker, textbook, pictures

INSTRUCTIONAL PROCEDURES

PERIOD 1-2

NOTE

Decomposition in nature: Ecological management

Macro and micro decomposers play essential roles in breaking down organic matter and recycling nutrients in ecosystems.

- Macro Decomposers: These are larger organisms that facilitate the initial stages of decomposition. Examples include scavengers like vultures, larger insects, and detritivores such as earthworms. They break down dead organic matter into smaller pieces, making it more accessible for microorganisms.

- Micro Decomposers: These are microscopic organisms, primarily bacteria and fungi, that further break down the organic material into simpler compounds. Fungi, especially molds and mushrooms, and various bacteria are crucial in decomposing complex organic molecules into nutrients that can be used by plants. This process is fundamental for nutrient cycling in ecosystems.

Importance and roles of decomposers to man

Decomposers, such as bacteria, fungi, and certain insects, play fundamental roles in ecosystems, providing various benefits:

1. Decomposers break down dead organisms and organic matter, returning essential nutrients like nitrogen, phosphorus, and carbon back into the soil. This nutrient recycling supports plant growth and sustains the overall health of ecosystems.
2. Decomposers help break down organic waste, including dead plants and animals, feces, and other organic materials. This decomposition process prevents the accumulation of waste and helps maintain a cleaner environment.
3. By breaking down organic matter, decomposers contribute to the formation of humus, a crucial component of fertile soil. Humus improves soil structure, water retention, and nutrient availability, enhancing conditions for plant growth.
4. Decomposers play a role in controlling the spread of diseases by breaking down dead organisms, including those that may carry harmful pathogens. This helps prevent the buildup of disease-causing agents in the environment.
5. Decomposers contribute to the energy flow within ecosystems by converting complex organic molecules into simpler forms. This process allows energy stored in organic matter to be released and utilized by other organisms in the food web.

Concept of maximum and minimum tolerance

The concepts of maximum and minimum tolerance refer to the range of environmental conditions within which a particular species can survive and function optimally. These concepts are essential for understanding an organism's ecological niche and its ability to adapt to different environmental factors.

1. Maximum Tolerance: Maximum tolerance is the upper limit of an environmental factor (e.g., temperature, pH, salinity) beyond which an organism cannot survive or function properly. For example, If a species has a maximum temperature tolerance of 40°C, exposure to temperatures above this threshold may result in physiological stress or even death for individuals of that species.
2. Minimum Tolerance: Minimum tolerance is the lower limit of an environmental factor below which an organism cannot thrive or carry out essential life processes effectively. For example: For a species with a minimum temperature tolerance of 5°C, exposure to temperatures below this limit may lead to reduced metabolic activity, impaired growth, or other negative effects.

Geographic range-graph illustrating maximum and minimum range tolerance

 Geographic range refers to the areas where a species of organism can only be found within the minimum and maximum limits of its tolerance.

This shows tolerance Range

Different abiotic factors like rainfall, temperature, light intensity, availability of food, relative humidity, day length, wind, etc are often responsible for the geographical boundaries of species of organisms. For example, the geographic range of the tropical rainforest is within the equator as a result of high rainfall and high temperatures, whereas tropical rainforest cannot be found at the Northern and Southern poles because of low rainfall and temperature.

EVALUATION: 1. Differentiate between macro and micro decomposers

2. Identify four importance and roles of decomposers to man
3. Discuss the concept of maximum and minimum tolerance

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively