Elective Biology Topics for Senior High Schools (SHS 1, 2 & 3)

Rationale For Teaching And Studying Elective Biology

The survival of humans and the development of nations would ever depend more and more on science and technology. Biology however is a branch of natural science which is devoted to the study of life and the activities of all living things from bacteria to high plants and animals. The survival of humans nevertheless depends greatly on the knowledge and understanding of the structure and functions of organisms and how they interact with one another and the environment. 

This invariably leads to the necessity of conservation of living things and other natural resources.  The need to teach Biology ultimately must be to explain the living world in terms of scientific principles although appreciating that, organisms behave in ways which often seem beyond the capabilities of their component parts. It is also to guide and inculcate in the learner skills in observing and measuring, formulating hypothesis, predicating and designing, investigating, recording data and interpreting results, drawing conclusions and communicating them. 

The knowledge, skills and attitudes acquired through the study of Biology is to provide the learner with the necessary basic tools for employment in laboratory, industry, agriculture, horticulture, forestry, health care, work with animals, marine and fresh water biology, information science, administration, finance, management and teaching. 

It further equips the learner for further studies and research in pure and applied science and technology that are vital areas for the advancement of society. Teaching elective biology in totality guides the learner and makes him/her capable of critical thinking, making meaningful decisions and solving problems.


General Aims

This content is designed to help reader to:

1. appreciate the diversity of living things.

2. understand the structure and functions of living things.

3. develop scientific approach to solving personal and societal (environmental, economic and health) problems.

4. develop practical skills required to work with scientific equipment, biological materials and living things.

5. collect, analyze and interpret biological data; and also present data graphically.

6. be aware of the existence of interrelationships between biology and other scientific disciplines.

7. sustain their interest in studying biology

8. appreciate and understand the interrelationships between organisms and themselves and with the environment.

9. recognize the value of biology to society and use it responsibly.

10. develop a sense of curiosity, creativity and critical mind.

11. provide a foundation for those who will develop a career in biological sciences.



The content of the blogpost has been designed in such a way as to provide readers with basic knowledge in biology for them to understand themselves and other organisms, which enable them make very informed choices as they interact with nature. The scope of the content of this blog also enables the learner pursue specialized careers relating to biology and fully prepares the students who wish to continue the study of biology at the tertiary level. 

SHS 1: Biology Topics 

Introduction to Biology

Biology is the study of the structure and function of living creatures, as well as how they interact with one another and with their surroundings. 

Cell is the basic structural and functional unit of all living organisms. 

The cells of multicellular organisms are surrounded by a watery fluid. 

Amoeba is a unicellular organism.  It has a jelly-like body with no definite shape surrounded by a thin semi permeable membrane.

It has a fixed slipper-shaped and is about 0.24mm in length. 

Euglena is unique organism with both plant and animal features. It is unicellular with a body covered with a thin, elastic and flexible pellicle, enclosing a cytoplasm. 

Spirogyra is a green free floating filamentous alga. 

Rhizopus is eukaryotic, multinucleated and non-photosynthetic organism. The body is made of fine thread-like structures called hyphae (singular: hypha). 

Mosses are small non-vascular plants and therefore lack tissue    

Fern has an underground stem called rhizome; thin adventitious roots

Cockroach has broad, dorso-ventrally flattened body and a relatively small head.

The body is divided into three segments: the head, thorax, and the abdomen. 

The weevil has a hard exoskeleton which is dark brown in color. 

It has triangular head with a pair of conspicuous compound eyes, a pair of short antennae and biting and chewing mouthparts. 

Termites are social insects commonly known "white ants".  Social insects are groups of insects which live together in a colony where there is division of labor 

Honey bees are social insects. There are three types of honey bees: drones, workers and queens.

It has slender body with three segments: head, thorax and abdomen.  The head has compound eyes, a pair of long, segmented antennae and an elongated, projecting

The body has a rounded head and a trunk which tapers to the tail. This gives the fish a streamlined shape which enables it to move smoothly through the water. 

The body of toad consists of only head and trunk. It has short, round neckless body with dry skin and no tails.

The body is covered by dry, horny, overlapping scales. 

23. DOMESTIC FOWL (Gallus domesticus)

The body consist of a head, trunk and tail. The head is small and round. 

SHS 2: Biology Topics 

Biological classification is the sorting and grouping of living things according to their common characteristics. Biologists place organisms into groups known as taxa (singular: taxon), based on their characteristics. 

Ecology is the scientific study of the interaction or inter-relationship of living organisms with each other and with their environment.

Population dynamics is the study of short-term and long-term changes in the size and age composition of populations, and the factors influencing these changes. 

Soil is mixture of organic and inorganic materials, which forms an ecosystem of living organisms and provides minerals for plant growth. 

Co-ordination is the ability to receive stimuli and to respond appropriately to ensure the maintenance of a steady state and survival of the organism. The two main system that bring about co-ordination are Nervous system and Endocrine system 

Sexual reproduction involves the fusion of two gametes. The gonads (the ovaries and testes) form the gametes (sex cells).  The fertilized egg develops within the female reproductive system and culminates in the birth of a baby. 

Skeleton is the hard parts of an animal that forms the framework for the body. Mammalian skeleton is composed of three types of organs; bones, cartilages and ligaments, tightly joined together.

Excretion is the removal of the metabolic wastes from the body of an organism. Wastes that are removed include carbon dioxide, water, salt, urea and uric acid.


Respiration is a sum total of chemical reactions which result in the breakdown of food substance to release energy with or without the use of oxygen. All organisms require energy to sustain life. 

The circulatory system consists of two main divisions; 

Cardiovascular System consists of the heart and the blood vessels which pump and carry blood respectively. Lymphatic System Consists of the lymphatic vessels and lymphoid tissues within the spleen thymus, tonsils and lymph nodes. 

Nutrition is the process by which organisms make or obtain food and utilizing it for growth maintenance. There are two types of nutrition. These are heterotrophic and autotrophic (holophytic) nutrition. 

SHS 3: Biology Topics 

Nucleic acids are large biological molecules, essential for all known forms of life. It forms the genetic material of living organisms. Nucleic acids are made from monomers known as nucleotides. 

The cell cycle is the sequence of events that takes place in cells. It leads to cell division and replication. In eukaryotes, the cell cycle can be divided into four distinct phases: G1 phase, S phase (synthesis), G2 phase and M phase.

Plants are the living, multicellular, eukaryotic organisms, which belongs to the kingdom Plantae. Plants produce their own food by photosynthesis and provide shelter, place and food for animals. 

The longitudinal section through root shows different zones or regions. 

Plant growth occurs by cell division, elongation and differentiation (specialization of cells). 

Photosynthesis is the process by which chlorophyll containing organisms (i.e., plants and algae) synthesize complex organic molecules (such as glucose) from simple inorganic substances (such as carbon dioxide and water) in the presence of light. Oxygen is given out as a by-product. 

In higher plants the exchange of gases takes place through stomata and lenticel. Oxygen diffuses through the stomata or lenticel into air spaces and move into the cells. 

Absorption of Water and Mineral salts
Water is absorbed by the root tips and root hairs of the root. The solutes concentration in the cell sap of the root hair is more than the soil water solution. 

The creation of a life form, by a similar life is called reproduction. Reproduction is the process by which living organisms give rise to new individuals of the same species. 

Food preservation usually involves preventing the growth of bacteria or other micro-organisms, as well as retarding the oxidation of fats that cause rancidity.

Natural resource refers to all the natural things on the earth. It includes everything, that is naturally available and that is not man-made.

This is referring to the differences in characteristics among individuals of the same species. This is due to inherited genes from parents or acquired through the environment.


Genetics is the study and understanding of the phenomena of heredity and variation. It is a branch of biology concerned with the structure, transmission and expression of hereditary information.

Post a Comment