Questions

The Food and Drug Administration is responsible for protecting the public health by ensuring the safety, efficacy, and security of human and veterinary drugs, biological products, and medical devices; and by ensuring the safety of our nation's food supply, cosmetics, and products that emit radiation.

When water is cooled from 4°C to 0°C, its density decreases.

When water cools from 4°C to 0°C, ice crystals begin to form because the water is approaching its freezing point. When water freezes, the water molecules form a lattice that increases the volume. As a result, the density decreases. This is why ice will float on top of water; ice has a lower density than the water.

Biological membranes are composed of phospholipids, Proteins and Carbohydrate groups attached to lipids and proteins.

Isotopes are atoms of the same element that have different mass numbers.

Example : Hydrogen, Deutirium and tritium all these have different mass but same atomic numbers.

Plants developing in dry conditions are called as xerophytes.

Materials that usually allow electricity to pass through them are called Good conductors of electricity.

Conductors conduct electrical current very easily because of their free electrons.

Examples are :: Aluminium, Gold, Copper, Silver

Materials that do not allow or oppose electrical current & make poor conductors are called Insulators.

Examples are :: Glass, Plastic, Wood, Air,...

The Earth has four major systems or spheres. These systems are

 1. The geosphere,

 2. The hydrosphere,

 3. The atmosphere, and 

4. The biosphere.

The biosphere is the system where we belong.