Explanation

• Carl Linnaeus (1707–1778), a Swedish botanist and zoologist, introduced the class name Mammalia in 1758 in the 10th edition of his book Systema Naturae.
• The term Mammalia refers to animals that possess mammary glands and feed their young with milk.
• Linnaeus is widely known as the father of modern taxonomy.
• Because he developed a systematic method of classifying organisms.
• Examples of mammals include humans, whales, bats, elephants, and dogs.

Last verified on 25-10-2026

Explanation

• Variation refers to differences in characteristics among individuals of the same species.
• These differences provide the raw material for evolution.
• Genetic variations arise through mutations and recombination, creating differences that natural selection can act upon.

Last verified on 25-10-2026

Explanation

• A 3:1 phenotypic ratio is classically associated with a monohybrid cross involving complete dominance and Mendelian segregation.
• In a dihybrid cross, linked genes may produce deviations from the expected 9:3:3:1 ratio because linked genes tend to be inherited together.

Last verified on 25-10-2026

Explanation

• The liver is an accessory organ of the digestive system. Food does not pass through it.
• The liver produces bile, which helps emulsify fats into smaller droplets for easier digestion.
• The gallbladder stores and concentrates bile, releasing it into the small intestine when needed.

Last verified on 25-10-2026

Explanation

• Antiserum is blood serum containing specific antibodies against a particular antigen, toxin, or infectious agent.
• These antibodies help neutralize harmful substances or identify specific pathogens.
• Antiserum may provide passive immunity, which offers immediate but temporary protection.

Last verified on 25-10-2026

Explanation

• Proteins perform a wide range of cellular functions, including catalysing chemical reactions, transporting substances, and supporting cell structure.
• Enzymes are mostly proteins that speed up biochemical reactions essential for life.
• Proteins are made of amino acids linked together by peptide bonds.

Last verified on 25-10-2026

Explanation

• Peroxisomes contain enzymes that break down harmful substances and help protect cells from toxic compounds.
• They break down hydrogen peroxide (H₂O₂) into water and oxygen using the enzyme catalase.

Additional information:

• Golgi body modifies, packages, and transports proteins.
• Lysosomes digest waste materials and worn-out cell components.

Last verified on 25-10-2026

Explanation

• Homeostasis is the ability of an organism to maintain a relatively stable internal environment despite changes in external conditions.
• It regulates body temperature, blood glucose levels, water balance, and blood pH.
• The nervous system and endocrine system work together to regulate many homeostatic processes, mainly through negative feedback.

Last verified on 25-10-2026

Explanation

• The pharynx passes air into the larynx.
• It is the voice box.
• It is part of the respiratory system.
• The glottis is the opening between the vocal folds that allows air to pass through the larynx.
• The larynx directs air into the trachea, which carries it toward the bronchi and lungs.
• Air pathway: Pharynx → Larynx → Trachea → Bronchi → Lungs.

Last verified on 25-10-2026

Explanation

• Peripheral proteins are located on the inner or outer surface of the cell membrane.
• They are not embedded deeply in the lipid bilayer.
• They perform important functions, including cell signalling, enzymatic activity, and supporting the cell membrane.

Additional information:

• Integral proteins, in contrast, are embedded within the lipid bilayer and may extend across the entire membrane.
• Plasmodesmata are microscopic channels connecting adjacent plant cells, allowing substances and signals to pass between them.

Last verified on 25-10-2026