Explanation

• During photosynthesis, water molecules are split in the light-dependent reactions. This process is called photolysis.
• The oxygen released into the atmosphere comes from water (H₂O).
• The splitting of water also provides electrons and hydrogen ions needed for photosynthesis.

Last verified on 31-10-2026

Explanation

• HIV (Human Immunodeficiency Virus) causes AIDS (Acquired Immunodeficiency Syndrome).
• HIV is an enveloped retrovirus that attacks CD4 T-helper cells.
• It weakens the immune system, making the body more vulnerable to infections.

Last verified on 31-10-2026

Explanation

• Alanine is an α-amino acid with the molecular formula C₃H₇NO₂.
• It contains an amino group (–NH₂), a carboxyl group (–COOH), and a methyl group (–CH₃).
• Alanine is one of the 20 standard amino acids used to build proteins.

Last verified on 31-10-2026

Explanation

• O-negative (O−) red blood cells can generally be donated to all ABO and Rh blood groups, making O− the universal red-cell donor.
• O-positive (O+) red blood cells can be donated to O+, A+, B+, and AB+ recipients.

Last verified on 30-10-2026

Explanation

• Seminiferous tubules are tiny, highly coiled tubes inside the testes where sperm are produced through a process called spermatogenesis.
• The testes also produce testosterone, the primary male sex hormone.
• After production, sperm mature further in the epididymis, where they are stored temporarily.

Last verified on 30-10-2026

Explanation

• Immunology is the branch of biology and medicine that studies the immune system, its functions, and its disorders.
• Immunity is the body's ability to resist infections and harmful substances.

Last verified on 30-10-2026

Explanation

• The Golgi body consists of stacks of flattened, membrane-bound sacs called cisternae.
• The Golgi apparatus modifies, sorts, and packages proteins and lipids received from the endoplasmic reticulum.
• These materials are packaged into vesicles for transport to other parts of the cell or for secretion outside the cell.

Last verified on 28-10-2026

Explanation

• Enzyme inhibition is commonly classified into two main types: reversible and irreversible inhibition.
• Reversible inhibition occurs when an inhibitor binds temporarily to an enzyme.
• Its common forms include competitive, non-competitive, and uncompetitive inhibition.
• Irreversible inhibition occurs when an inhibitor permanently inactivates an enzyme, often by forming a strong chemical bond.

Last verified on 28-10-2026

Explanation

• Microfilaments are thin, solid protein fibres found in the cytoskeleton of eukaryotic cells.
• They are approximately 7 nm in diameter.
• They are mainly composed of the protein actin.
• Microfilaments help maintain cell shape, support cell movement, and participate in muscle contraction and cell division.

Last verified on 28-10-2026

Explanation

• Viruses are not included because they are acellular.
• It means they lack a cellular structure.
• It can reproduce only inside living host cells.

Additional information:

• The five-kingdom classification was proposed by Robert H. Whittaker in 1969.
• The five kingdoms are Monera, Protista, Fungi, Plantae, and Animalia.

Last verified on 28-10-2026