Explanation: Islets are tiny clusters of cells in the pancreas. These make insulin which controls blood sugar levels.

Explanation: Human placenta is derived from Chorion. The chorion and amnion together forms amniotic sac.

Explanation: The heart is made up of muscles. It is an involuntary organ. The heart is made up of muscle called as myocardium.

Explanation: Stethoscope is an acoustic medical device for auscultation. It has a small disc shaped resonator that is placed against the chest and two tubes connected to earpieces.

Explanation: Liver is the largest gland of human body. It is present on the right side of the body.

Explanation: Alpha cells are present in the Islets of Langerhans. They make up to 20% of human islet cells and synthesize insulin hormone.

Explanation: Placenta found in humans is called Discoidal. It is a placenta in which the chorionic villi are arranged in a circular plate.

Explanation: Human sperm is haploid. Human sperm moves with the help of Flagellum. It is found in the tail region of the sperm.

Explanation: Division of human egg is Holoblastic and unequal. Holoblastic cleavage is seen in the eggs containing moderate to sparse amount of yolk. Holoblastic cleavage is the complete division of an isolecithal or microlecithal egg into blastomeres.

Explanation: Retina is the inner most layer of human eye. It is light sensitive layer. The retina converts the light rays into impulses that travel through the optic nerve to brain where they are interpreted as the image we see.

Explanation: The breathing rate in humans is controlled by Medulla oblongata. It is present in the brainstem. It is an important part of the brain.