Living organisms:

Living things and non-living things have clear differences that JAMB loves to test. Living organisms carry out life processes like respiration, growth, reproduction, and response to their environment. They need food for energy, can move on their own, and eventually die. Non-living things like a stone or a car don't do any of these things naturally.

Think about a mango tree in your compound. It grows bigger, reproduces by making seeds, responds to sunlight by growing towards it, and uses nutrients from soil. A mango fruit that falls from the tree stops growing once it's picked. The tree is alive; the picked fruit gradually dies because it cannot perform life processes anymore.

The key difference is metabolism—living things break down food for energy, while non-living things never do this. Non-living objects might move when pushed or change shape, but they don't move or change by themselves.

Both plant and animal cells contain a nucleus that controls cell activities, cytoplasm where reactions occur, and a cell membrane controlling what enters and leaves. Animal cells are roughly spherical and found in humans, dogs, and insects. Plant cells are rectangular and found in crops like cassava, maize, and tomato plants. Key differences exist: plant cells have a rigid cell wall outside the membrane for support, while animal cells lack this. Plant cells contain chloroplasts for photosynthesis, making plants green, but animal cells don't. Plant cells also have large vacuoles storing water and nutrients, whereas animal cells have small ones. Both contain mitochondria for energy production. Understanding these structures helps explain why plants are rigid while animals are flexible.

Both plant and animal cells contain different parts that work together like a team. Each component has a specific job to do. The nucleus controls all activities in the cell, just like a principal controls a school. Mitochondria produces energy for the cell to work, similar to how a generator provides power in Nigerian homes during blackouts. The cell membrane controls what enters and leaves the cell, protecting it like a security guard. Plant cells have extra parts animals lack—chloroplasts capture sunlight to make food, which is why plants are green, and a cell wall provides rigid support so plants can stand upright. Animal cells have centrioles that help during cell division. In your body, red blood cells lack nuclei for more space to carry oxygen, while liver cells have many mitochondria because they need lots of energy. Understanding these functions helps you predict how cells behave in different situations.

Both plant and animal cells contain a nucleus, mitochondria, and cell membrane, making them eukaryotic cells. However, they have distinct structures that suit their different functions. Plant cells possess a rigid cell wall outside the cell membrane, giving them a fixed rectangular shape, while animal cells lack this wall and appear round or irregular. Think of a plant cell like a brick house with walls (the cell wall), while an animal cell is like a balloon.

Plant cells also contain chloroplasts for photosynthesis and large vacuoles that store water and maintain firmness—similar to how a cassava plant stays upright. Animal cells lack chloroplasts since they cannot make their own food, and their vacuoles, when present, are much smaller. Additionally, plant cells have plasmodesmata connecting adjacent cells, whereas animal cells have gap junctions instead.

The five levels of organization describe how life is structured from smallest to largest. Starting with the cell, which is the basic unit of life, everything builds up logically. Cells group together to form tissues, which are collections of similar cells doing the same job—like the muscle tissue in your leg. Tissues then combine to make organs, such as your heart or stomach, each with a specific function. Multiple organs work together as organ systems; for example, your digestive system includes your mouth, esophagus, stomach, and intestines all cooperating. Finally, organ systems make up the complete organism—you as a whole person. Think of a cassava plant: its cells form tissues, tissues form organs like roots and leaves, these organs create systems, and all systems together create the complete plant. This logical sequence shows how simple parts organize into increasingly complex structures.

Living organisms are living things that carry out life processes. These include all animals, plants, fungi, and microorganisms around us. The main characteristic of living organisms is that they perform seven life processes: nutrition, respiration, growth, reproduction, excretion, sensitivity, and movement.

Think of a cassava plant growing in your family farm. It takes in nutrients from soil through its roots, grows taller, responds to sunlight by turning its leaves, and eventually produces seeds for reproduction. Even when you cannot see the process happening, it's respiring and removing waste products. Humans, animals, fungi like the mushrooms sold in Lagos markets, and bacteria are all living organisms because they perform these life processes.

The key difference between living and non-living things is that living organisms maintain organization, use energy, and eventually die and decompose.

When you examine any living thing closely, you notice specific features that help you identify and classify it. These external characteristics include body structure, color, size, shape, and special adaptations. For example, a mosquito has six legs, wings, and a long proboscis for sucking blood, while a tilapia fish has fins, scales, and gills. These features aren't random—they help organisms survive in their environments. The lion's powerful claws and teeth make it a hunter, whereas a goat's flat teeth suit its herbivorous diet. By carefully observing these external traits, scientists can group organisms into families and understand how each creature has adapted to its lifestyle.

Living things are organized in a specific pattern, from the smallest to the largest. It starts with the cell, which is the basic unit of life. Cells group together to form tissues—like muscle tissue or nerve tissue. When different tissues work together, they create organs such as your heart or lungs. Several organs functioning as a unit make an organ system, like your digestive system. All organ systems working together form a complete organism, which is the whole living thing—you, a dog, or a cassava plant. After organisms, you have populations (groups of the same species living in one area), communities (different species living together), and ecosystems (communities plus their physical environment). Think of a Nigerian farm: individual cassava plants are organisms, all cassava plants together form a population, and that cassava farm plus the soil, water, and insects around it make an ecosystem.