December 2021

The colour of the skin and hair of a human being is decided by a pigment called ‘melanin’. In the early ages, all ancient human beings were the same colour but with the increase in population, they started spreading out all over the world. Those who lived near the equator were exposed to the sun’s […]

If harmful substances are released, they can pollute the environment. Damage to plants through air pollution is evident in several ways. A big change in the colour of the leaf may be visible in a short time and appear as dead tissue, or it can develop slowly as yellowing of the leaf. There may be

It is important for soil to be loose and not packed down. If the soil in the field is packed down or compacted, farmers need to plough it before they can plant their seeds. Compacted soil prevents the roots of the plants from spreading comfortably. This further limits their access to soil nutrients and also

National parks are created for the purpose of conservation and protection of the flora and fauna of the area in addition to improving the tourism of the country. People can visit parks for camping and also walking in some areas. Parks provide a safe haven to the wildlife of the area, that is, free from

Wind greatly affects the growth of plants. Most plants produce flowers containing separate male and female sex cells. Male sex cells are called ‘pollen’ and the process of joining them with female sex cells is called ‘pollination’. Some plants pollinate themselves, but most rely on their pollen being carried to another plant before a new

With so many different kinds of soil on planet earth, some soils are extremely nutritious for plants while others are not. Some plants, like the venus flytrap, have the dangerous ability to lure their prey into their trap or between their leaves for nutrition and supplementing the low concentration of nitrogen in their habitat. As

A stem supports the leaves and flowers of the plant in addition to transporting water and food (the nutrients of the plant), around the plant. There are some plants, like cactus, where the food is made in the stem rather than in leaves. The stem holds up leaves to the sun to complete the process

The middle of the hurricane is called the ‘eye’ and is calm. It is found in the centre and is between 30 – 50 km in diameter. The eye is the point around which the rest of the storm rotates and where the lowest surface pressures are found. The air around is going at such

An increase in the earth’s average temperatures is called ‘global warming’. Deforestation and burning of fossil fuels are believed to be primary culprits. These release large quantities of gases such as carbon dioxide into the atmosphere, which trap more of the sun’s energy as heat and warm the planet. One of the most immediate effects

No living thing can exist on its own. Each living thing is part of an ecosystem and has complicated relationships with other living beings and with its habitat. Each living being depends on its environment to supply it with its basic and extended needs, including food, water and shelter. Each living being needs other organisms

Fungi lack chlorophyll and do not make food by photosynthesis. Instead, they break down and digest the food outside their bodies before they absorb it. There are more than 70,000 known species of fungi including mushrooms, toadstools, yeasts and moulds. Fungi break down dead animals and plant matter, releasing chemicals and nutrients back into the

Nitrogen is needed by all living things. It reaches the soil in rain and in dead and rotting matter. Bacteria in the soil combine nitrogen with other substances to create nutrients which plants can absorb. Of all the essential nutrients, nitrogen is required by plants in the largest quantity. It is a component of chlorophyll

Plants are known as primary producers because they make their own food by a process known as photosynthesis. They take sunlight and use it to help make food. Plants are at the bottom level in the food chain and they make all the food and energy that is found in the ecosystem. Without plants, other

The peach is hairy primarily due to its nature. The fuzzy cover of the peach acts as a kind of protection for the fruit. Not only does it help keep the small bugs away, but the added hair over the skin increases the surface area of the fruit, allowing it to control the moisture of

Maize grains are hard on the outside, but inside they are soft and slightly moist. When grains are heated, the water inside them also becomes hot. The water turns into a hot steam that is tightly sealed inside the grain. Finally, the pressure is so hard that the steam gets the hull to blow up.