Explanation

White blood cells (leukocytes) are part of the immune system.

They play a key role in defending the body against infections, diseases, and foreign invaders.

They help maintain overall health.

Explanation

Without sunlight, there would be no scattering of light by the Earth's atmosphere.

This means that no scattered light would reach our eyes, and the sky would appear black.

Explanation

Benjamin Franklin invented the lightning rod, a device used to protect buildings from lightning strikes.

He made this invention in 1752 as part of his experiments with electricity.

Explanation

The flu is caused by an influenza virus

Flu Risk Factors · chronic lung diseases such as asthma

ND2-03-2023

Explanation

Vitamins B and C are water-soluble vitamins, meaning they dissolve easily in water.

• Vitamin B: Includes several B vitamins (B1, B2, B3, etc.), all of which are water-soluble.
• Vitamin C (Ascorbic acid): Also highly soluble in water.

Explanation

Dolly was the world's first cloned sheep.

Dolly was born on 5 July 1996.

Dolly was a female domestic sheep, and the first mammal cloned from an adult somatic cell, using the process of nuclear transfer.

Dolly was cloned by Ian Wilmut.

Explanation

Explanation

Hepatitis C is a liver infection caused by the hepatitis C virus. 

Hepatitis C is often described as “acute,” meaning a new infection, or “chronic,” meaning long-term infection.

Explanation

Oxyacetylene flame is used in welding and cutting metals due to its high temperature.

It provides a flame temperature of about 3200°C, making it suitable for industrial applications.

Explanation

• Exposure to sunlight triggers the production of vitamin D in the skin.
• Specifically, ultraviolet B (UVB) rays from the sun interact with a compound called 7-dehydrocholesterol, converting it into vitamin D3 (cholecalciferol).
• Vitamin D is essential for calcium absorption, bone health, and immune system regulation.