Tag: zoology

Quizzes (289) Questions (5869)

Questions Related to zoology

Multiple choice zoology endocrine system and chemical co-ordination pineal gland pituitary gland and pineal gland pineal gland and thymus

The pineal body is considered as

  1. An endocrine gland

  2. An organ concerned with voluntary actions

  3. An organ concerned with vision

  4. A vestige of third eye and endocrine gland
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
The pineal body is made up of the secretory cells called the pineolocytes. It is attached to the roof of the epithalamus in the diencephalon of the forebrain. During the embryonic development, it is found attached to the brow spot between the eyes of the developing embryo. In some reptiles, the pineal gland is present in the form of the parietal eye or the pineal eye which is photosensitive and is involved in regulating the diurnal cycle. In mammals, it does not form the photosensitive structure but it is involved in the secretion of the hormone called the melatonin which regulates the sleep-wake cycle. It is degraded during the bright light and accumulates in dim light.
Hence, the correct answer is 'A vestige of third eye and endocrine gland'
Multiple choice zoology endocrine system and chemical co-ordination pineal gland pituitary gland and pineal gland pineal gland and thymus

Identify the hormone with its correct matching of source and function.

  1. Oxytocin - posterior pituitary, growth and maintenance of mammary glands

  2. Melatonin- Pineal gland, regulates the normal rhythm of sleepwake cycle

  3. Progesterone- Corpus luteum, stimulation of growth and activities of female secondary sex organs

  4. Atrial natriuretic factor - ventricular wall, increases the blood pressure
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

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. 

So, the correct answer is option B.

Multiple choice zoology endocrine system and chemical co-ordination pineal gland pituitary gland and pineal gland pineal gland and thymus

Gradual atrophy degeneration with ageing its shown by

  1. pineal gland

  2. thymosin

  3. adreal cortex

  4. Both a and b
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The pineal gland is known to undergo gradual calcification and atrophy with age. Thymosin is produced by the thymus, which also undergoes involution, but the pineal gland is a classic example of age-related degeneration.

Multiple choice zoology endocrine system and chemical co-ordination pineal gland pituitary gland and pineal gland pineal gland and thymus

Which of the following is responsible for sleep wake cycle movement?

  1. Dopamione

  2. Melatonin

  3. Serotonin

  4. Adrenaline
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Option B is correct here.

The circadian rhythm is set by the suprachiasmatic nucleus of the hypothalamus, which regulates the sleep-wake cycle.
The suprachiasmatic nucleus projects to the pineal gland to release melatonin, which promotes sleep. 
At the time of morning melatonin secretion through pineal gland get low and get stop slowly because of that person get wake up.

Multiple choice zoology endocrine system and chemical co-ordination pineal gland pituitary gland and pineal gland pineal gland and thymus

Melatonin is modified

  1. Amino acid

  2. Peptide

  3. Steroid

  4. Protein
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • 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'.
Multiple choice zoology endocrine system and chemical co-ordination pineal gland pituitary gland and pineal gland pineal gland and thymus

Which of the following gland in our body controls the biological clock in the human body?

  1. Pitutary gland

  2. Thyroid gland

  3. Pineal gland

  4. Parathyroid gland
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

  • 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.

So, the correct answer is 'Pineal gland'.

Multiple choice zoology endocrine system and chemical co-ordination pineal gland pituitary gland and pineal gland pineal gland and thymus

Which of these hormones may have a primary role in many circadian rhythms?

  1. Insulin

  2. Estradiol

  3. Melatonin

  4. Epinephrine
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

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.

So, the correct answer is 'Melatonin'.

Multiple choice zoology excretory system of human structure of nephron excretory system nephron

Malpighian body is found

  1. In kidney of vertebrates and is involved in the formation of urine

  2. In vertebrates and involved with filtration of blood

  3. In insects and involved in excretion

  4. In invertebrates and involved with filtration of blood
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

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.

Multiple choice zoology excretory system of human structure of nephron excretory system nephron

Nitrogenous waste in the Malpighian tubule flows into

  1. Haemocoel

  2. Vacuole

  3. Intestine

  4. Duodenum
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

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.

Multiple choice zoology excretory system of human structure of nephron excretory system nephron

The number of uriniferous tubules in each kidney of man is

  1. About 10,000

  2. About 5,000

  3. Cannot be calculated
  4. About 1.0 x 10$^6$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
The excretory organ present in humans is called a kidney. The nephrons are the structural and functional units of the kidney. Nephrons are also called as uriniferous tubules. The body of the uriniferous tubule is composed of Renal corpuscle, Proximal convoluted tubule(PCT) Henle's loop and Distal convoluted tubule(DCT) and collecting duct. The number of uriniferous tubules in each kidney of man is about 1.0 x 1000000.
So, the correct answer is 'Option D'.