Explanation

DNA (Deoxyribonucleic Acid) has a double helix structure,

which consists of two long strands of nucleotides twisted around each other.

This structure was discovered by James Watson and Francis Crick in 1953.

Explanation

Nucleic acids (DNA/RNA) are present in:

Nucleus:

• Contains genomic DNA (eukaryotic cells).

Mitochondria:

• Have their own mtDNA (vital for energy production).

Chloroplasts (in plants/algae):

• Contain cpDNA for photosynthesis-related functions.

Explanation

• Plants don’t need shelter but they need air.
• Air provides the necessary carbon dioxide for photosynthesis and oxygen for respiration.

Explanation

Circadian rhythms are natural, internal biological cycles that follow a 24-hour cycle, such as the sleep-wake pattern.

These rhythms are regulated by the biological clock and respond to environmental cues like light and darkness.

Explanation

Phenotype refers to the observable characteristics or traits of an organism (like eye color, height).

It results from the interaction of the genotype with the environment.

Explanation

Gram-positive bacteria, such as Bacillus and Clostridium, are known for producing endospores.

Explanation

Explanation

Blood, since family ties are fundamentally based on blood relationships.

Explanation

Bradykinin causes leakage of fluid from blood vessels, contributing to swelling during an inflammatory response.

Explanation

 Lysosomes contain hydrolytic enzymes that are involved in breaking down various biomolecules through hydrolysis.