UNIT 1: Activities of Living Things
1.0 Introduction
This unit on activities of living things presents the organism, plant or animal as an
entity that is capable of existing. To say an organism exists, is the same thing as
saying that it is busy, it is full of life, it is going on, it is alive, it is full of energy.
If you look into any biology textbook (see reference at the end of the unit), it will
give you list of things that living things do to qualify them as living things and
differentiates them from non living things.
2.0 Objectives:
When you complete this unit successfully, you will be able to:
1 Differentiate living things from non-living things.
2 List the characteristics of living things.
3 Describe in detail those activities that distinguish living things from non living
things.
4 Give examples of living things.
5 Explain how energy is transformed by living things.
6 Classify living things based on oxygen requirement.
1.3.0 Activities of living things.
1.3.1 Ingestion
1.3.2 Assimilation .
1.3.3 Growth
1.3.4 Excretion
1.3.5 Reproduction .
1.3.6 Responsiveness
1.3.7 Co-ordination
1. 3.8 Regulation
1.3.9 Energy transformation in living things
1.3.10 Classification of living things based on energy utilization
1.4.0 Conclusion
1.5.0 Summary
1.6.0 Tutor Mark Assignment
1.7.0 References and further readings
1.8.0 Additional materials
1.3.0 Activities of Living Things
All living things manifest certain characteristics. They demonstrate the ability to
use energy from the environment for survival and carry out their various
10
, activities. For continuous survival, protoplasm must be added. Waste must be
gotten rid off. New ones or offspring must be produced. Nine characteristics
distinguish living things from non-living things.
These are:
1. Ingestion
2. Assimilation
3. Growth
4. Reproduction
5. Waste elimination
6. Responsiveness
7. Co-ordination
8. Regulation
9. Movement
1.3.1 Ingestion
All living things feed one way or the other. They take in food for many reasons,
chief among these is for energy purposes. The organism needs energy to carry out
all the other activities associated with living things. There are two kinds of living
things, plant and animal. Plant manufacture food, i.e. basic materials are secured,
light energy is utilised to convert the materials to complex nutritive substances,
which are used as food. Animals depend on plants for food.
1.3.2 Assimilation
Living organisms utilise food (nutrients) to maintain life. This is done by a
process called metabolism. It is a chemical process involved in keeping the life of
the organism going. There are two aspects of metabolism, (a) anabolism
(substances are synthesised from simpler substances, e.g. photosynthesis..... (b)
catabolism (the breakdown of the substances).
1.3.3 Growth
Growth simply put is increase of materials in an organism. This is done in stages,
a unicellular organism increases its protoplasm while a multicellular organism
increases the number of cells, and every living cell is made up of protoplasm.
1.3.4 Excretion
All living organisms get rid of unwanted products (waste). As a result of cell
activities in the protoplasm, many materials formed (byproducts) which are not
beneficial to the cell and if left will cause harm to the cell.
11
,1.3.5 Reproduction
All cells of living organisms multiply or divide. This multiplication or division
enables the organism to perpetuate their species. Reproduction can take different
forms. (a) fission into two or more parts, (b) fusion of protoplasmic material from
two sources (i.e. male and female gametes) resulting in an offspring.
1.3.6 Responsiveness
Living organisms respond to forces or anything external, even internal, i.e. any
stimuli in the environment, it could be change of weather. Organisms do this by
many methods. You will learn some of these in detail as your study progresses.
1.3.7.1.3.8 Co-ordination and Regulation
Chemical and physical changes in the organism are involved in all these activities.
There is a general process of co-ordination and regulation by enzymes to keep the
system of the organisms balanced and unified. Materials are exchanged, energy is
exchanged between the organism and its environment.
You have gone through the various activities most living things carry out. Now
think of some living things around you, check through the list of activities and see
if your example of a living thing (say, yourself or an insect) manifest these
characteristics, non-living things such as wood.
1.3.9.0 Energy Transformation in Living Things
Looking through all the activities of living things, energy seems to be a linking
factor between all the activities. Each of the activities expend energy to be carried
out. In figure 3.9, energy transformation in living organisms is shown. Study this
very well. It is the energy from the external environment that is being used by
green plants to synthesize organic nutrients. Animals also use the energy in the
environment. Look closely at the flow chart. Green plants synthesize food from
the sun, the energy is transferred along the line through some processes and the
organism uses the energy for growth, reproduction, locomotion, co-ordination and
excretion.
1.3.9.1 Energy Transformation in Living Things
Energy available in the external environment
Kinetic radiation Potential: Chemical bonds
Green plants use light Animals and other organism lacking
energy to Synthesize chlorophyll absorb energy-rich
organic requirements compounds previously synthesized by
green plants.
12
, NUTRITION
Controlled transfer of energy from chemical bonds is suitable organic molecules to the
phosphate bonds in ATP.
RESPIRATION
Chief uses of the energy transferred to ATP bonds
Metabolism Production of heat, light,
sound,
(chemical work) Movements electrical impulses, etc.
(various
(mechanical work) forms of work).
Enlargement Multiplication
Growth Reproduction Locomotion and Sensitivity, other co-
ordinating
Other movement regulatory processes
All these activities lead to the formation of unwanted byproducts. Energy is expended in
the elimination of these.
EXCRETION
Source: Vines and Rees: plants and animal biology p.12.
1.10 Classification of Living things Based on Oxygen utilization
Living things can be classified into three groups, based on their oxygen
requirement (a) those that use free oxygen to breakdown complex compound -
aerobic, (b) those that can respire without oxygen ,.J anaerobic, (c) those that can
exist with or without oxygen, e.g. yeast.
Energy is needed for the organism to move from place to place (locomotion).
Plant cells do not move like animal cells, but there is movement within the cells
of a plant i.e. movement of the protoplasm.
Activities 1.3.1
a. Take yourself as an example of a living thing. Which of these activities do you
do?
b. Describe how you engage in the activities.
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1.0 Introduction
This unit on activities of living things presents the organism, plant or animal as an
entity that is capable of existing. To say an organism exists, is the same thing as
saying that it is busy, it is full of life, it is going on, it is alive, it is full of energy.
If you look into any biology textbook (see reference at the end of the unit), it will
give you list of things that living things do to qualify them as living things and
differentiates them from non living things.
2.0 Objectives:
When you complete this unit successfully, you will be able to:
1 Differentiate living things from non-living things.
2 List the characteristics of living things.
3 Describe in detail those activities that distinguish living things from non living
things.
4 Give examples of living things.
5 Explain how energy is transformed by living things.
6 Classify living things based on oxygen requirement.
1.3.0 Activities of living things.
1.3.1 Ingestion
1.3.2 Assimilation .
1.3.3 Growth
1.3.4 Excretion
1.3.5 Reproduction .
1.3.6 Responsiveness
1.3.7 Co-ordination
1. 3.8 Regulation
1.3.9 Energy transformation in living things
1.3.10 Classification of living things based on energy utilization
1.4.0 Conclusion
1.5.0 Summary
1.6.0 Tutor Mark Assignment
1.7.0 References and further readings
1.8.0 Additional materials
1.3.0 Activities of Living Things
All living things manifest certain characteristics. They demonstrate the ability to
use energy from the environment for survival and carry out their various
10
, activities. For continuous survival, protoplasm must be added. Waste must be
gotten rid off. New ones or offspring must be produced. Nine characteristics
distinguish living things from non-living things.
These are:
1. Ingestion
2. Assimilation
3. Growth
4. Reproduction
5. Waste elimination
6. Responsiveness
7. Co-ordination
8. Regulation
9. Movement
1.3.1 Ingestion
All living things feed one way or the other. They take in food for many reasons,
chief among these is for energy purposes. The organism needs energy to carry out
all the other activities associated with living things. There are two kinds of living
things, plant and animal. Plant manufacture food, i.e. basic materials are secured,
light energy is utilised to convert the materials to complex nutritive substances,
which are used as food. Animals depend on plants for food.
1.3.2 Assimilation
Living organisms utilise food (nutrients) to maintain life. This is done by a
process called metabolism. It is a chemical process involved in keeping the life of
the organism going. There are two aspects of metabolism, (a) anabolism
(substances are synthesised from simpler substances, e.g. photosynthesis..... (b)
catabolism (the breakdown of the substances).
1.3.3 Growth
Growth simply put is increase of materials in an organism. This is done in stages,
a unicellular organism increases its protoplasm while a multicellular organism
increases the number of cells, and every living cell is made up of protoplasm.
1.3.4 Excretion
All living organisms get rid of unwanted products (waste). As a result of cell
activities in the protoplasm, many materials formed (byproducts) which are not
beneficial to the cell and if left will cause harm to the cell.
11
,1.3.5 Reproduction
All cells of living organisms multiply or divide. This multiplication or division
enables the organism to perpetuate their species. Reproduction can take different
forms. (a) fission into two or more parts, (b) fusion of protoplasmic material from
two sources (i.e. male and female gametes) resulting in an offspring.
1.3.6 Responsiveness
Living organisms respond to forces or anything external, even internal, i.e. any
stimuli in the environment, it could be change of weather. Organisms do this by
many methods. You will learn some of these in detail as your study progresses.
1.3.7.1.3.8 Co-ordination and Regulation
Chemical and physical changes in the organism are involved in all these activities.
There is a general process of co-ordination and regulation by enzymes to keep the
system of the organisms balanced and unified. Materials are exchanged, energy is
exchanged between the organism and its environment.
You have gone through the various activities most living things carry out. Now
think of some living things around you, check through the list of activities and see
if your example of a living thing (say, yourself or an insect) manifest these
characteristics, non-living things such as wood.
1.3.9.0 Energy Transformation in Living Things
Looking through all the activities of living things, energy seems to be a linking
factor between all the activities. Each of the activities expend energy to be carried
out. In figure 3.9, energy transformation in living organisms is shown. Study this
very well. It is the energy from the external environment that is being used by
green plants to synthesize organic nutrients. Animals also use the energy in the
environment. Look closely at the flow chart. Green plants synthesize food from
the sun, the energy is transferred along the line through some processes and the
organism uses the energy for growth, reproduction, locomotion, co-ordination and
excretion.
1.3.9.1 Energy Transformation in Living Things
Energy available in the external environment
Kinetic radiation Potential: Chemical bonds
Green plants use light Animals and other organism lacking
energy to Synthesize chlorophyll absorb energy-rich
organic requirements compounds previously synthesized by
green plants.
12
, NUTRITION
Controlled transfer of energy from chemical bonds is suitable organic molecules to the
phosphate bonds in ATP.
RESPIRATION
Chief uses of the energy transferred to ATP bonds
Metabolism Production of heat, light,
sound,
(chemical work) Movements electrical impulses, etc.
(various
(mechanical work) forms of work).
Enlargement Multiplication
Growth Reproduction Locomotion and Sensitivity, other co-
ordinating
Other movement regulatory processes
All these activities lead to the formation of unwanted byproducts. Energy is expended in
the elimination of these.
EXCRETION
Source: Vines and Rees: plants and animal biology p.12.
1.10 Classification of Living things Based on Oxygen utilization
Living things can be classified into three groups, based on their oxygen
requirement (a) those that use free oxygen to breakdown complex compound -
aerobic, (b) those that can respire without oxygen ,.J anaerobic, (c) those that can
exist with or without oxygen, e.g. yeast.
Energy is needed for the organism to move from place to place (locomotion).
Plant cells do not move like animal cells, but there is movement within the cells
of a plant i.e. movement of the protoplasm.
Activities 1.3.1
a. Take yourself as an example of a living thing. Which of these activities do you
do?
b. Describe how you engage in the activities.
13
