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WAEC biology: 10 key Topics that WAEC set every year with some worked examples

Firstly I will like to advise all the waec candidate reading this article to follow like and share this article for more update, also the parents or guidance of any WAEC Candidate reading this article can also follow for more update for their children.

As we all know that Biology is one of the very important subject for all the secondary school science students

However any students that want to further his her Education must have at least last credit C5 or C6 before he or she can be admitted into science course in higher institution.

Below are the 10 key Topics in biology that WAEC set every year.

1 Organization of life

We know it all starts with the cell. And for somespecies it ends with the cell. But for others, the cells come together to form tissues, tissues form organs, organs form organ systems, and organ systems combine to form an organism. Levels of Organization

The living world can be organized into different levels. For example, many individual organisms can be organized into the following levels:

Cell : Basic unit of structure and function of all living things.

Tissue : Group of cells of the same kind.

Organ : Structure composed of one or more types of tissues. The tissues of an organ work together to perfume a specific function. Human organs include the brain, stomach, kidney, and liver.

Plant organs include roots, stems, and leaves. Organ system: Group of organs that work together to perform a certain function. Examples of organ systems in a human include the skeletal, nervous, and reproductive systems.Organism : Individual living thing that may be made up of one or more organ systems.

2 Ecosystem

An ecosystem consists of all the living things (biotic factors ) in a given area, together with the nonliving environment (abiotic factors ). The nonliving environment includes water, sunlight, soil, and other physical factors.

A group of similar ecosystems with the same general type of physical environment is called a biome .

The biosphere is the part of Earth where all life exists, including all the land, water , and air where living things can be found. The biosphere consists of many different biomes .

3 Diversity of Life

Life on Earth is very diverse. The diversity of living things is called biodiversity . A measure of Earth’s biodiversity is the number of different species of organisms that live on Earth. At least 10 million different species live on Earth today. They are commonly grouped into six different kingdoms.

Examples of organisms within each kingdom 

4 Cell theory

The cell theory developed in 1839 by microbiologists Schleiden and Schwann describes the properties of cells. It is an explanation of the relationship between cells and living things. The theory states that: all living things are made of cells and their products. new cells are created by old cells dividing intobtwo.

cells are the basic building blocks of life. The cell theory applies to all living things, however big or small. The modern understanding of cell theory extends the concepts of the original cell theory to include the following:

The activity of an organism depends on the total activity of independent cells.

Energy flow occurs in cells through the breakdown of carbohydrates by respiration. Cells contain the information necessary for the creation of new cells. This information is known as ‘hereditary information’ and is contained within DNA.

The contents of cells from similar species are basically the same.

Cells are the smallest form of life; the functional and structural units of all living things. Your body contains several billion cells, organised into over 200 major types, with hundreds of cell-specific functions. Some functions performed by cells are so vital to the existence of life that all cells perform them (e.g. cellular respiration). Others are highly specialised (e.g. photosynthesis).

5 cell membrane

The cell membrane , also called the plasma membrane, physically separates the intracellular space (inside the cell) from the extracellular environment (outside the cell). All plant and animal cells have cell membranes. The cell membrane surrounds and protects the cytoplasm . Cytoplasm is part of the protoplasm and is the living component of the cell.

The cell membrane is composed of a double layer (bilayer) of special lipids (fats) called phospholipids . Phospholipids consist of a hydrophilic (water-loving) head and a hydrophobic (water-fearing) tail. The hydrophobic head of the phospholipid is polar (charged) and can therefore dissolve in water. The hydrophobic tail is non-polar (uncharged), and cannot dissolve in water.

The lipid bilayer forms spontaneously due to the properties of the phospholipid molecules. In an aqueous environment, the polar heads try to form hydrogen bonds with the water, while the non-polar tails try to escape from the water. The problem is solved by the formation of a bilayer because the hydrophilic heads can point outwards and from hydrogen bonds with water, and the hydrophobic tails point towards one another and are ‘protected’ from the water molecules.

6 Cell Division

Cell division is the process cells go through to divide. There are several types of cell division, depending upon what type of organism is dividing. Organisms have evolved over time to have different and more complex forms of cell division. Most prokaryotes, or bacteria , use binary fission to divide the cell. Eukaryotes of all sizes use mitosis to divide. Sexually-reproducing eukaryotes use a special form of cell division called meiosis to reduce the genetic content in the cell.

7 Supporting Tissues

Supporting Tissues

The development of stable supporting elements has been an important prerequisite for the evolution of large terrestrial organisms. Animals have endo- or exoskeletons that correspond in function to the woody stems or trunks of plants.

The architectural design of the plant’s body of vegetation is very complex. Thin petioles carry heavy and flat laminas, stems support leaves, flowers and fruits. All plant organs are exposed to mechanical strains. 

1. The collenchyma, a tissue of living cells,

2. the sclerenchyma, a tissue of nearly always dead cells.

3. the vascular tissue consisting of both living and dead cells. It is responsible for the transport and dispersal of water, nutriments and assimilates.

8 Transportation in plants

Transpiration is the process of water movement through a plant and its evaporation from aerial parts, such as leaves, stems and flowers . Water is necessary for plants but only a small amount of water taken up by the roots is used for growth and metabolism. The remaining 97–99.5% is lost bytranspiration and guttation.

9 Kidney structure and functions

The kidneys are two bean-shaped organs in the renal system.

They help the body pass waste as urine. They also help filter blood before sending it back to the heart.

The kidneys perform many crucial functions, including: maintaining overall fluid balance regulating and filtering minerals from blood filtering waste materials from food, medications, and toxic substances creating hormones that help produce red blood cells, promote bone health, and regulate blood pressure.

10 Liver

The liver is an organ only found in vertebrates which detoxifies various metabolites, synthesizes proteins and produces biochemicals necessary for digestion and growth. In humans, it is located in the right upper quadrant of the abdomen, below the diaphragm.


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