AFMC Biology Mock Test - 2 - NEET MCQ

Largest gland in human body is liver and Thyroid is largest endocrine gland.

• Lathyrism is a neurotoxic disorder caused by eating certain legumes of the genus Lathyrus.
  It is due to the lathyrogen present in them which are basically the derivatives of amino acids.
• This disease leads to progressive weakness and stiffness, prickling/tingling sensations, and alterations in the collagen cross-links that ultimately lead to alterations in the bone material and pattern and therefore leads to skeletal deformities.

The parasympathetic nervous system, via the vagus nerve, and the hormone gastrin stimulate the parietal cell to produce gastric acid, both directly acting on parietal cells and indirectly, through the stimulation of the secretion of the hormone histamine from enterochromaffin-like cells (ECL).

Control of Gastric Secretions:

Cirrhosis: A degenerative disease of the liver, marked by an excessive formation of tissue and contraction of the organ, usually brought on by chronic alcohol abuse. — cirrhotic.

Brain cells (neurones) do not regenerate because centriole is not found in neurones.

The part of alimentary canal which does not secrete any enzyme is Oesophagus.

Ammonia is rapidly removed from the circulation in the liver, converted into a water soluble compound known as urea. Ammonia is toxic to the CNS because it reacts with the α-ketoglutarate to form glutamate.

• Mitosis is a process where a single cell divides into two identical daughter cells (cell division).
• During mitosis one cell divides once to form two identical cells. The major purpose of mitosis is for growth and to replace worn out cells.

• Kupffer cells, the resident macrophage in the liver, comprise the largest population of resident tissue macrophages in the body.
• It comprises the major phagocytic activity of what was classically termed the reticular-endothelial system and now more properly called the mononuclear phagocytic system (139).

The ciliated epithelium in trachea, is in fact pseudostratified ciliated epithelium having long ciliated columnar cells and short cuboidal cells.

Plastid is an important site for the manufacture and storage of chemical compounds used by the cells of autotrophic organisms.

• Chromoplast is a plastid that consists of red, yellow and orange coloured pigments. They are usually found in fruits, flowers, roots, and aged leaves which gives distinct colours to these plant parts.
• The chromoplasts contain a pigment called lycopene, which is present in the form of crystals within the lumina of membrane sacs.

So, the correct answer is 'All of the above'.

The iodine-replete healthy adult has about 15–20 mg of iodine, 70%–80% of which is contained in the thyroid.

Insulin decrease the blood glucose level and Glucagon increase the blood glucose level hence they have opposite effect to each other.

Throughout your life, your skin will change constantly, for better or worse. In fact, your skin will regenerate itself approximately every 27 days.

Reticulocytes are immature red blood cells (RBCs). In the process of erythropoiesis, red blood cell formation, reticulocytes developed and mature in the bone marrow and then circulate for about a day in the bloodstream before developing into mature red blood cells.

Homo sapiens is the scientific name of human, termed by the father of modern biological classification Carolus Linnaeus in 1758.

The pure line is true-breeding genotypes:

• A line that has been rendered homozygous for all genes under consideration in successive generations.
• A line in which homozygous individuals produce only homozygous offspring like parents.

Thus, pure line breed refers to homozygosity only.

Klinefelter's Syndrome: XXY
The presence of 2 X Chromosomes causes the appearance of feminine characters in this male.
Example: Gynecomastia

In haemophilia a protien is absent in affected individual which helps in blood clotting due to which simple cut results in nonstop bleeding.

• There will be 50% chances because the sex of foetus depends on the male not on female and the male has two types of sex chromosomes 'X and Y'.
• If X fuses with female gamete than it will produce a girl child and if Y fuses with the female gamete then it will produce a boy child.

• Liver fluke belongs to Platyhelminthes which is having an organ level of organization.
• Sponges having a cellular level of organization
• Starfish belongs to echinoderms having an organ system level of organization.

Taenia is bisexual animal and mature proglottides have both male and female reproductive organ.

Echinodermata are exclusively marine organisms.
Example: Sea cucumbers, Sea urchins, Sand dollars, and Brittle stars.

To date, no fresh water or terrestrial echinoderms are known.

The syrinx  is the vocal organ of birds. Located at the base of a bird's trachea, it produces sounds without the vocal folds of mammals.

Coelomate animals or Coelomata (also known as eucoelomates — "true coelom") have a body cavity called a coelom with a complete lining called peritoneum derived from mesoderm (one of the three primary tissue layers).

Body Cavities:

• Placental mammal, (infraclass Eutheria), any member of the mammalian group characterized by the presence of a placenta, which facilitates the exchange of nutrients and wastes between the blood of the mother and that of the fetus.
• The placentals include all living mammals except marsupials and monotremes.

Euspongia is the scientific name of common bath sponge.

Euspongia:

Mucus helps frog in forming moist skin as skin is its respiratory organ.

• The important species producing good quality of pearl are Pinctada vulgaris (schumachar), Pinctada marigavitifera (Linn), Pinctada chemnitzi (Philippi), Pinctada anamioides (Reeve) and Pinctada alropurpurea (Dunker).
• All these species are Marine and it is the marine forms which produce the pearl of fine quality.

Sponges belong to Porifera and it exhibits a cellular level of organization.
Hence, it is devoid of respiratory, excretory, and circulatory organs.