Ammonia, urea and uric acid are the excretory products in different animals. Ammonia is an excretory product in gaseous form in fishes, uric acid (white in colour) is in birds and urea is an excretory product in human beings.

The leaves of a plant have small pores which are known as stomata. The function of stomata is to evaporate excess of water from leaves and exchange of gases.

Each component of blood plays a role in particular. For example, RBC in respiration process by binding haemoglobin with oxygen, platelets in the clotting of blood and white blood cells as defensive agents by acting against germs.

The number of times a heartbeats in a minute is known as pulse rate. The average pulse rate of a resting person is usually 72 - 80 beats per minute.

Pulmonary vein carries oxygenated blood, and not deoxygenated blood. Therefore, option (1) is the correct answer.

Stimulation of the vagus nerve will make the heartbeat slower.

Blood is the fluid tissue which transports oxygen and nutrients to various parts of body. Platelets in blood also help in blood clotting during any cut or wound. Red blood cells contain haemoglobin which is a respiratory pigment and WBC fights against infections.

Therefore, statement (2) is incorrect. Thus, it is the correct answer.

Vascular tissue called phloem transports the food produced in leaves to different parts of  plant.

Veins are thin-walled blood vessels which carry deoxygenated blood from all parts of the body to heart. The valves present in veins prevent the back flow of blood.

The right side of heart deals with deoxygenated blood.

Minerals are absorbed into cells by active transport.

Blood is red in colour due to haemoglobin present in the red blood cells. Therefore, test tube A will show unusual colour of blood because of deficiency in red blood cells.

Heart of a fish is special because it only has venous blood.

The cells that are rigid and full of water are called turgid.

Option (2) is the correct answer.