Tag: zoology

Melatonin, is a hormone that is produced by the pineal gland and regulates sleep and wakefulness. Blood levels of the pineal hormone melatonin are high at night and low during the day. There, a special center called the suprachiasmatic nucleus (SCN) initiates signals to other parts of the brain that control hormones, body temperature and other functions that play a role in making us feel sleepy or wide awake. During the day the pineal is inactive. When the sun goes down and darkness occurs, the pineal is "turned on" by the SCN and begins to actively produce melatonin, which is released into the blood. As a result, melatonin levels in the blood rise sharply and you begin to feel less alert. Sleep becomes more inviting. 

• Melatonin is a hormone that regulates sleep-wake cycles. It is primarily released by the pineal gland. 
• As a supplement, it is often used for the short-term treatment of trouble sleeping such as from jet lag or shift work. 
• Melatonin is a hormone which is a protein made up of amino acids. 
• Hence, Melatonin is a modified Amino acid. 
• So, the correct answer is 'amino acid'.

• The pineal gland is an endocrine gland located on the dorsal side of the forebrain. Pineal secretes a hormone called melatonin.
  
• Melatonin plays a very important role in the regulation of a 24-hour (diurnal) rhythm of our body. For example, it helps in maintaining the normal rhythms of the sleep-wake cycle, body temperature. In addition, melatonin also influences metabolism, pigmentation, the menstrual cycle as well as our defense capability. Hence the gland in our body that controls biological clock is a Pineal gland.

The circadian rhythm or 24 hours diurnal rhythm of our body is maintained by Melatonin hormone secreted from the Pineal gland which is located on the dorsal side of forebrain. In addition, the melatonin hormone even assist in metabolism, pigmentation and even maintaining our defence capabilities.

Malpighian body is also called kidney corpuscle. Malpighian body is the structure at the beginning of a vertebrate nephron, consisting of a glomerulus and its surrounding Bowman's capsule. It mainly involved in filteration of blood. Thus, option B is correct.

Malpighian tubules are excretory organs of insects like cockroach, grasshopper etc. These are blind ending excretory tubes which open into the alimentary canal near the junction of the midgut and hind gut. These tubules remove nitrogenous wastes from the haemolymph and also function in osmoregulation.