Explanation

• Compounds with the same molecular formula but different arrangements of atoms are called isomers.
• Isomers can have different chemical and physical properties despite having the same number of atoms.

• Additional information:
  • Example of isomers: C₂H₆O → Ethanol (CH₃CH₂OH) and Dimethyl ether (CH₃OCH₃)
  • Isomerism is classified into structural isomers and stereoisomers.

Explanation

• DNA (Deoxyribonucleic Acid) contains the sugar deoxyribose, which is a five-carbon sugar.
• It forms the backbone of the DNA molecule along with phosphate groups.

Additional information:

• Sugars in nucleic acids:
• DNA – Deoxyribose
• RNA – Ribose
• Glucose – energy source in cells
• Fructose – sugar in fruits
• Galactose – sugar in milk

Last verified on 19-01-2026

Explanation

• Carbon has a valency of 4, meaning it can form 4 covalent bonds with other atoms.
• This property allows carbon to form complex organic compounds.
• It is the backbone of all organic molecules.

Additional information:

Examples of Carbon Compounds (5):

1. Methane (CH₄)
2. Ethane (C₂H₆)
3. Glucose (C₆H₁₂O₆)
4. Ethanol (C₂H₅OH)
5. Carbon dioxide (CO₂)

Last verified on 19-01-2026

Explanation

• A virion is the fully developed, infectious form of a virus capable of infecting a host.
• It contains genetic material (DNA or RNA) and a protein coat (capsid), sometimes with an envelope.
  

Additional information:

• Capsomere: Protein subunit of the capsid.
• Envelope: Lipid layer around some viruses.
• Prion: Infectious protein.

Last verified on 19-01-2026

Explanation

• Ascorbic Acid is commonly known as Vitamin C.
• It is essential for growth, repair, and maintenance of body tissues.
• Prevents scurvy, a disease caused by Vitamin C deficiency.

Additional information:

Sources of Vitamin C (5):

1. Orange
2. Lemon
3. Guava
4. Strawberry
5. Bell pepper

Functions:

• Antioxidant
• Collagen synthesis
• Strengthens immunity

Last verified on 19-01-2026

Explanation

HIV (Human Immunodeficiency Virus) was first identified in 20 May 1983

By researchers Luc Montagnier and Françoise Barré-Sinoussi in France.

Their discovery linked HIV to AIDS, leading to significant advancements in understanding and managing the disease.

Explanation

H5N1 is a type of influenza virus

Causes a highly infectious

Also known as avian influenza.

Occurs mainly in birds, is highly contagious among birds, and can be deadly, especially in domestic poultry

Explanation

The troposphere is the lowest layer of Earth’s atmosphere.

It extends from the Earth’s surface up to about 8–15 km (varies with latitude).

All weather phenomena like rain, clouds, and storms occur in this layer.

It contains approximately 75–80% of the atmosphere’s mass.

The temperature in the troposphere decreases with altitude.

Explanation

Metamorphic rocks are formed from pre-existing rocks (igneous, sedimentary, or older metamorphic rocks).

They are changed by high heat and/or pressure without melting.

Common examples include marble (from limestone) and gneiss (from granite).

The process is called metamorphism, meaning “change in form.”

Explanation

O negative (O⁻) blood group is called the universal donor.

It can be transfused to any blood group (A, B, AB, or O).

O⁻ lacks A, B, and Rh antigens, preventing immune reactions in recipients.