Sharon Stars International SchoolWEEK 1
TOPIC: LIVING AND NON - LIVING THINGS
DEFINITION OF BIOLOGY
The term Biology is drawn from two Greek words: ‘bio’ meaning life and ‘logos’ meaning study. Hence Biology can simply be defined as the study of life or the study of living organisms. Biology is the natural science that deals with the study of the physical structure and chemical processes in living organisms.
BRANCHES OF BIOLOGY
The main branches of Biology are:
1. Botany: the study of plants.
2. Zoology: the study of animals. Other branches include Anatomy (the study of the structure of organisms), Biochemistry (the study of chemical reactions related to life).
3. Ecology: the study of interactions of living organisms with one another and with the non - living elements of their environment.
4. Genetics: the study of genes and heredity.
5. Microbiology: the study of microscopic organisms.
6. Physiology: the study of the functions and mechanisms occurring in living organisms, etc.
SCIENTIFIC APPROACH
When scientists research, they make use of a scientific approach to collect measurable evidence. The steps of scientific method are:
The scientific method is a step-by-step process used by scientists to investigate natural phenomena, solve problems, and answer questions. It ensures that scientific work is accurate, systematic, and reliable.
The process begins with observation, which is the careful use of the senses or instruments to notice events in the environment. For example, a student may observe that some plants grow taller than others. From this, the scientist may carry out classification, which means grouping things based on similarities and differences, such as plants that grow in sunlight and those that grow in shade.
The next process is measurement, where scientists record quantities such as length, weight, or time using standard units and instruments. After this comes inference, which is a reasonable explanation based on observation. For instance, one may infer that plants in the sun grow faster because they receive more energy.
These processes lead to problem identification, where the scientist states the question to be solved, such as: Why do plants in sunlight grow taller than those in shade? A hypothesis is then formed. A hypothesis is a tentative answer or educated guess that tries to explain the problem, e.g. Plants grow faster because they receive more sunlight for photosynthesis.
The hypothesis is tested through experimentation, where controlled tests are carried out to check if the idea is correct. During the experiment, results are carefully recorded and analyzed in tables, charts, or graphs. A conclusion is then drawn, showing whether the hypothesis was supported or rejected. If the hypothesis is repeatedly tested and supported by evidence, it may develop into a theory. A theory is a well-tested explanation of natural events, such as the cell theory. When a theory has been tested for a long time and universally accepted without exception, it may become a scientific law, such as the law of gravity.
The final step in the scientific method is reporting findings, where scientists share results in reports, journals, or presentations. This allows others to learn from the investigation and even repeat it.
The scientific method is important because it helps scientists think critically, ensures accuracy, and makes discoveries useful to society.
LIVING AND NON - LIVING THINGS
Everything in our environment can be classified as either living things or non-living things. The main difference between them is that living things show the characteristics of life, while non-living things do not. Living things are organisms that have life. They carry out certain activities known as the characteristics of living things, remembered by the acronym MR NIGER CAD:
Although some non-living things may appear to show one or two features of living things (like a moving car or fire that “grows”), they are not truly alive because they cannot perform all the characteristics of life.
CHARACTERISTICS OF LIVING THINGS
Living things are known by the activities they perform, which are called the characteristics of life. These can be remembered using the acronym MR NIGER CAD.
M – Movement
Living things can move from one place to another or move parts of their body. Animals move freely while plants show movement by bending towards light or opening and closing their flowers.
R – Respiration
This is the process by which living things break down food substances to release energy needed for activities such as movement, growth, and reproduction.
N – Nutrition (Feeding)
All living things need food. Plants make their own food through photosynthesis (autotropic), while animals feed on plants or other animals to obtain energy (heterotropic/ holozoic nutrition).
I – Irritability (Sensitivity)
This is the ability of living things to detect and respond to changes (stimuli) in their environment. For example, humans withdraw their hand from a hot object, and plants grow towards light.
G – Growth
Growth is defined as an irreversible and permanent increase in size, dry mass or weight of an organism. The purpose of growth is to enable organisms to repair or replace damaged or old tissues in their body. This will lead to complexity and maturation. For example, a baby grows into an adult, and a seed grows into a mature plant.
E – Excretion
Excretion can be defined as the removal of waste production of metabolism from the body. Living things remove waste products from their bodies to avoid harm. Humans excrete sweat, urine, and carbon dioxide, while plants excrete oxygen and water vapor.
R – Reproduction
This is the ability of living things to produce young ones of their own kind, ensuring the continuity of life. For example, hens lay eggs, and plants produce seeds. Reproduction occurs in two forms: (i) Sexual (ii) Asexual
C – Competition
Living things struggle for limited resources such as food, water, space, and mates in order to survive.
A – Adaptation
This is the ability of living things to adjust to their environment for survival. For example, fish have gills for breathing in water, and desert plants store water in their stems.
D – Death
All living things eventually die after completing their life cycle. Death marks the end of life.
DIFFERENCES BETWEEN PLANTS AND ANIMALS
| ANIMALS | PLANTS |
| Animals can move the whole body from place to place | Plants are fixed and do not move. Only parts of the body such as roots, stems and leaves can move |
| Has heterotropic mode of nutrition (depends on already - made food) | Has autotrophic mode of nutrition. (produces its own food using energy from the sun) |
| Has sense organs | Absence of sense organs |
| Possesses no chlorophyll or chloroplast | Possesses chlorophyll or chloroplast |
| Stores carbohydrates as glycogen | Stores carbohydrates as starch. |
| Responds quickly to stimuli using sense organs.. | Responds slowly to stimuli
|
| Animals have fixed number of body parts which are usually compact | Plants have no fixed number of body parts are branching is continuous. |
| Growth is limited | Growth is unlimited |