Explanation

• Platelets, also called thrombocytes.
• They are blood cells that play a vital role in blood clotting.
• When a blood vessel is injured, platelets aggregate to form a plug that stops the bleeding.

Explanation

The melting point of ice at normal atmospheric pressure is 0 °C (zero degrees Celsius).

Key Points:

• 0 K (zero Kelvin) is equivalent to -273.15 °C, which is absolute zero, the lowest possible temperature.
• 100 °C is the boiling point of water at normal atmospheric pressure.

Explanation

• In the human heart, blood returning from the lungs via the pulmonary veins drains into the left atrium.
• From there, it flows through the mitral valve into the left ventricle, which pumps it out to the rest of the body through the aorta.

Explanation

• The shortest distance between two points is called displacement.
• Displacement is a measure of the straight-line distance between two points.
•  It is a scalar quantity.

Key Point: The longest distance between two points is called the circumference (if the points are on a circle) or a diagonal (if the points are on a polygon or a rectangle).

Explanation

Plasmodium is a genus of protozoan parasites that cause malaria.

There are several species of Plasmodium that can infect humans, including P. falciparum, P. vivax, P. ovale, and P. malariae.