Explanation

Crossing over is a form of recombination (or genetic recombination).

It's a type of genetic recombination that occurs during meiosis,

Involving the exchange of genetic material between non-sister chromatids of homologous chromosomes.

This process creates new combinations of alleles, increasing genetic diversity. 

Explanation

A single strand of nucleic acid tagged with a radioactive molecule is called a probe.

These probes are often used in molecular biology techniques to detect specific DNA or RNA sequences. 

Explanation

One human leg has 31 bones including the femur, tibia, fibula, patella, tarsals, metatarsals, and phalanges.

These bones support movement and bear the body’s weight.

Explanation

Children aged 12 to 14 years typically need 2000–2400 calories daily, depending on gender and activity level.

This supports their growth, development, and energy needs.

Explanation

During swimming, knees and ankles play a key role in kicking movements.

These joints allow flexion and extension, providing thrust in the water.

Explanation

In a straight forward roll, the hands push against the ground to initiate and guide the roll.

This helps shift the body weight forward and maintain balance during the movement.

Explanation

Heart muscle (cardiac muscle) contracts automatically without conscious control — it's involuntary.

Neck and leg muscles are voluntary and controlled by conscious effort.

Explanation

Sesamoid bones are extremely small bones found in within muscles or tendons (e.g., the kneecap or patella).

They protect tendons from stress and wear.

Explanation

The oxygen cycle is closely linked with the carbon cycle through processes like photosynthesis and respiration.

Plants release O₂ during photosynthesis (using CO₂), while animals and humans consume O₂ and release CO₂ during respiration.

Explanation

Salads often contain vegetables rich in vitamin A, beta-carotene, and antioxidants, which support eye health.

Regular salad intake can help maintain good vision and protect against eye disorders.