Mole | MCQs

Explanation

The nucleus is the most important part of the cell as it controls all the activities of the cell, including growth, metabolism, and reproduction.

It contains the cell's genetic material (DNA) which regulates gene expression and directs protein synthesis.

Explanation

Explanation

Explanation

Cytosine does not form a bond with adenine because its hydrogen bond donors and acceptors are not complementary.

Cytosine typically forms three hydrogen bonds with guanine, whereas adenine forms two hydrogen bonds with thymine.

The patterns of hydrogen bonding in cytosine and adenine do not match, preventing the formation of a stable pair.

Explanation

DNA (Deoxyribonucleic acid) is the primary molecule that encodes genetic information in cells.

It is a long, double-stranded helix made up of nucleotides, which are the building blocks of genetic information.

Explanation

• Replication is the process by which a cell makes an exact copy of its DNA before cell division, ensuring that the new cell receives a complete set of genetic instructions.
• This process is crucial for the transmission of genetic information from one generation of cells to the next.

Explanation

As two atoms come closer, attractive forces (like between electrons and nuclei) try to pull them together.

Simultaneously, repulsive forces (like between electron clouds or nuclei) also increase, balancing the interaction.

Explanation

Chemical changes involve a transformation where new substances with different properties are created.

It often through reactions like combustion, rusting, or digestion.

Explanation

Acids are not slippery; instead, they usually have a sour taste and can be corrosive.

Bases are the ones that feel slippery to touch.

Explanation

Dissolving sugar in water is a physical change—no new substance is formed.

The sugar can be recovered by evaporation, showing it’s not a chemical reaction.