Explanation

• The thickness of skin is around 2 millimeters (0.08 inches) thick.
• The skin has two main layers (epidermis - outer layer) and the (dermis - inner layer).
• The epidermis is about 0.05-1.5 millimeters thick.
• The dermis is about 1-4 millimeters thick.

Explanation

According to the World Health Organization (WHO), the industrial limit of sound in industries must be 75 dB (Decibels).

Explanation

The life cycle of a frog:

• Frogspawn (Eggs): Laid by the female frog in water.
• Tadpoles (Larvae): Hatch from eggs, aquatic, and feed on algae.
• Froglet (Young Frog): Undergo metamorphosis, develop limbs, and lose tail.
• Frog (Adult): Fully developed, breathing air, and reproducing.

Explanation

• In a normal man, the average heart beat is 72 times per minute.
• But it may vary from 70-80 beats per minute.

Explanation

• During breathing, the clean, moist, and warm air enters the windpipe called the Trachea.
• The trachea is also known as the windpipe.
• It is a tube that connects the throat (pharynx) to the lungs, allowing air to pass through during breathing.

Explanation

• The brain is the command center of the body, controlling everything from movement and sensation to thought and emotion.
• It processes information, sends signals to muscles and glands, and regulates various bodily functions, making it the central control system of the body.

Explanation

• The Earth rotates on its axis, completing one full rotation in 24 hours.
• This is the equivalent of 1,440 minutes or 86,400 seconds.
• This rotation is what gives us day and night, as different parts of the planet face towards or away from the Sun.

Explanation

• The freezing point of water is 0°C (zero degrees Centigrade). 
• The boiling point of water on the Centigrade scale (also known as the Celsius scale) 100°C (one hundred degrees Centigrade).

Explanation

• There are around 639 skeletal muscles.
• The three main types of muscle include skeletal, smooth, and cardiac.
• The sartorius muscle is a thin, long, superficial muscle in the anterior compartment of the thigh.

Explanation

A compound machine is a machine that is made up of two or more simple machines.

A bicycle, a crane, wheel borrow and scissors are examples of compound machines because they are made up of multiple simple machines, such as:

• Wheels and axles (simple machine: wheel)
• Pedals and levers (simple machine: lever)
• Gears and pulleys (simple machine: pulley)
• Inclined planes (simple machine: inclined plane)