Explanation

• The liver is considered the main centre of metabolism because it regulates carbohydrates, proteins, and fats.
• It converts excess glucose into glycogen for storage and helps regulate blood sugar levels.
• The liver also detoxifies harmful substances and produces bile for fat digestion.
• It is the largest internal organ of the human body.

Last verified on 02-11-2026

Explanation

Iron deficiency can lead to Anaemia, a condition characterized by:

• Low red blood cell count
• Pale skin
• Fatigue
• Shortness of breath
• Dizziness

Last verified on 02-11-2026

Explanation

• Decomposers break down dead plants, animals, and organic waste into simpler substances.
• They return essential nutrients to the soil and environment, making them available for reuse by producers.
• Examples include bacteria and fungi.
• Decomposers play an essential role in maintaining nutrient cycles, such as the carbon and nitrogen cycles.

Last verified on 02-11-2026

Explanation

• The biosphere is the highest level of biological organization because it includes all ecosystems on Earth.
• The order of ecological organization is organism → population → community → ecosystem → biosphere.
• The biosphere includes all regions of Earth where life exists, including land, water, and parts of the atmosphere.

Last verified on 02-11-2026

Explanation

• Renewable resources are resources that can be naturally replenished through physical or biological processes.
• Examples include sunlight, wind, water, and forests when managed sustainably.

Additional information:

• Non-renewable resources, such as coal, petroleum, and natural gas, take millions of years to form and cannot be replaced quickly.

Last verified on 02-11-2026

Explanation

• Evolution refers to the gradual development or change of something over time.
• In biology, evolution explains how living organisms change over generations.
• Charles Darwin is widely known for developing the theory of evolution by natural selection.

Last verified on 02-11-2026

Explanation

• Monotremes are mammals that lay eggs instead of giving birth to live young.
• The platypus and echidnas are the only living groups of monotremes.
• Placentals develop their young inside the uterus with the help of a placenta.
• Marsupials usually give birth to underdeveloped young that continue developing in a pouch.
• Cetacea includes whales, dolphins, and porpoises.

Last verified on 27-10-2026

Explanation

• The fourth ventricle is a fluid-filled cavity located in the hindbrain, between the brainstem and cerebellum.
• It lies behind the pons and upper medulla oblongata and in front of the cerebellum.
• It is continuous with the cerebral aqueduct above and the central canal of the spinal cord below.

Last verified on 27-10-2026

Explanation

• The biceps brachii contracts to bend the elbow joint, a movement called flexion.
• The triceps brachii performs the opposite movement, extending or straightening the elbow.
• The biceps and triceps work as an antagonistic pair: when one contracts, the other generally relaxes to allow movement.

Last verified on 27-10-2026

Explanation

• Exhaled air contains about 16% oxygen.
• Because the body absorbs some oxygen during gas exchange in the lungs.
• Atmospheric air contains approximately 21% oxygen.
• Exhaled air contains approximately 4% carbon dioxide, compared with about 0.04% in atmospheric air.

Last verified on 27-10-2026