1. The largest endocrine gland in the human body is the thyroid gland. This gland is located in the front and bottom of the neck and produces thyroxine and calcitonin hormones.

2. The thyroxine hormone helps regulate the body's metabolism, while the calcitonin hormone helps regulate calcium levels in the blood.

The most important characteristic of evergreen plants is that they always remain green, no matter what the weather. They do not shed their leaves, but replace them with new leaves every year. Evergreen plants thrive well in cold or dry climates, where plants that lose their leaves in winter may die.

Chirmi or Gunja are the seeds of a creeper, which come in two colours, red and white. The color of half of its seeds is red or white and the other half is black. There is also a black-seeded Gunja which is extremely rare.

The conversion of ferric chloride (FeCl₃) to ferrous chloride (FeCl₂) is not specifically called "degradation." Instead, it is a type of chemical reaction known as a reduction reaction. In this process, ferric chloride (FeCl₃), which contains iron in the +3 oxidation state, gains electrons and is reduced to ferrous chloride (FeCl₂), where iron is in the +2 oxidation state. The reduction reaction involves the gain of electrons, leading to a decrease in the oxidation state of iron.

1. Kala-azar disease is caused by the protozoa Leishmania donovani.

2. It is a parasitic protozoa that belongs to the class Mastigophora or Flagellata. It is caused by sand fly (Phlebotomus) which causes kala azar or dumdum fever.

1. Involuntary actions like blood pressure, salivation and vomiting are controlled by the medulla.

2. The medulla oblongata, also called the medulla, is the lowest part of the brain and the lowest part of the brainstem.

3. The medulla oblongata or simply the medulla is a long stem-like structure that is part of the brain.