31 Years NEET Previous Year Questions: Structural Organisation in Animals

Mast cells are granulated wandering leucocyte  cells. Their granules contain histamine  which is vasodilator and heparin  (anticoagulant). These take part in body defence and allergic reaction. Vasopressin is released by posterior lobe of pituitary. Relaxin  is released by placenta. Calcitonin is released by thyroid. Serotonin and melanin are released by intermediate lobe of pituitary gland.

Areolar connective tissue has rich supply of nerve fibres and blood vessels. It joins skin epithelia with muscles, nerves & blood vessels. Binding of body parts together is the main function of areolar connective tissue.

At the site of infection, the infectious organism release some chemical to increase the flow of mast cells towards the inflammation site. Mast cell release histamine which increases the permeability of blood vessels at the site of inflammation so that more blood supply takes place. The site gets warm and red due to this.

Bowman’s glands are found in olfactory epithelium which secrete mucus to keep the olfactory epithelium moist and free from germs.

It is ciliated epithelium which bears numerous delicated hair like outgrowths the cilia, arising from basal granules. The cilia remains in rhythmic motion and creates current to transport the materials which comes in contact with them

Ciliated epithelium has simple columnar epithelial cells, but in addition, they posses fine hair-like outgrowths, cilia on their free surfaces. These cilia are capable of rapid, rhythmic, wavelike beatings in a certain direction. This movement of the cilia in a certain direction causes the mucus, which is secreted by the goblet cells, to move (flow or stream) in that direction. Ciliated epithelium is usually found in the air passages like the nose. It is also found in the uterus and fallopian tubes of females. The movement of the cilia propel the ovum to the uterus.

The cell junctions called tight, adhering and gap junctions are found in epithelial tissue. Epithelial tissue covers the whole surface of the body. It is made up of cells closely packed and ranged in one or more layers. This tissue is specialised to form the covering or lining of all internal and external body surfaces. Epithelial tissue that occurs on surfaces of the interior of the body is known as endothelium.

The kind of tissue that forms the supportive structure in our pinna (external ears) is also found in tip of the nose. External pinna is made up of elastic cartilage. It is passage towards middle ear.

Squamous epithelium is formed of thin discoidal and polygonal cells that fit like tiles in a floor, so is also called pavement epithelium. It is found in the walls of blood vessels, in the alveoli of lung for exchange of gas, and in Bowman’s capsule of nephron for ultra filtration.

The ciliated columnar epithelial cells in humans are known to occur in bronchioles and fallopian tube. The cilia move back and forth to help the movement of particles over the epithelial surface.

Thus, the correct answer is option B.

Cockroach takes the food after grounding by its mandibles and gizzard.

The lining of a blood vessel is simple squamous epithelium. Inner most lining of blood vessels is called endothelium. “Squamous” refers to the fact that the cells are flat.

The erythrocytes or RBCs in frog are large, oval and biconvex nucleated cell with respiratory red pigment haemoglobin in its cytoplasm.

Males bear a pair of short, thread-like anal styles which are absent in females, anal/caudal styles arise from the 9th abdominal segment in the male cockroach.

So, the correct option is 'Males bear a pair of short thread-like anal styles'.

A. Males bear short oval styles not present in females

EXPLANATION: Male and female cockroaches can be distinguished externally by the presence of anal styles. It is present in male cockroach, but not in female cockroach. The abdomen of male cockroach is slender and the last segment of the abdomen is pointed. In the 9th sternum of the abdomen of male cockroach un-jointed anal style is present.