Explanation

Excess melanin-stimulating hormone (MSH) is secreted in Addison's disease

Because the adrenal glands are not producing enough cortisol

Which leads to an increase in ACTH (adrenocorticotropic hormone)

Which in turn stimulates the production of MSH, resulting in hyperpigmentation (darkened skin). 

Explanation

The hormone that suppresses ovulation is progesterone. 

Progesterone, particularly high levels during pregnancy, prevents ovulation by inhibiting follicular development and providing negative feedback to the hypothalamus, reducing the release of gonadotropin-releasing hormone (GnRH). 

Explanation

ADH (Antidiuretic Hormone), also known as vasopressin.

It is released by the hypothalamus in the brain and stored in the posterior pituitary gland.

ADH regulates water reabsorption in the kidneys, leading to increased water retention and decreased urine production.

Explanation

Explanation

The tiny thin-walled ducts in the lungs of birds that open at both ends are called  Para-bronchi. 

In bird lungs, instead of alveoli, there are these thin-walled tubular structures called parabronchi where gas exchange occurs. 

Explanation

According to Erwin Chargaff's 1951 findings, the ratio of adenine (A) to thymine (T) in DNA is approximately 1:1.

This means that for every adenine molecule, there is a corresponding thymine molecule.

This observation, along with the similar 1:1 ratio of guanine (G) and cytosine (C), forms the basis of Chargaff's rules. 

Explanation

A group of carbohydrates containing 3 to 10 monosaccharides in straight or branched chains is called oligosaccharide.

These chains are linked together by glycosidic bonds. 

Explanation

The kidney, ureter, and bladder are key organs of the excretory system, responsible for removing waste from the body.

They help maintain water balance, filter blood, and produce urine.

Explanation

High-frequency radio waves from mobile phones may affect the brain’s electrical activity, leading to sleep disturbances and increased stress levels.

Studies have linked prolonged exposure to electromagnetic radiation with potential risks like headaches, anxiety, and reduced sleep quality.

Explanation

The respiratory system is responsible for supplying oxygen to the blood and removing carbon dioxide from the body.

Key organs include the lungs, trachea, and diaphragm, which help in breathing and gas exchange.