31 Years NEET Previous Year Questions: Structural Organisation in Animals - 2 - NEET MCQ

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.

During muscular contraction myosin cross bridges heads. Myosin is not only an actin binding protein, it is also an ATPase (an enzyme) which is activated by Ca²⁺ and Mg²⁺ ions. Hence, ATPase enzyme is located in myosin.

Fibrinogen, prothrombin, throm- boplastin are respectively clotting factors I, II and III.
Thromboplastin released from injured platelets or injured tissue. This converts prothrombin into thrombin in the presence of calcium ions. The thrombin converts fibrinogen into fibrin and the latter froms the clot.

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

Earthworms have no skeleton but during burrowing, anterior end becomes turgid and acts as a hydraulic skeleton. It is due to coelomic fluid. The coelom is filled with an alkaline milky coelomic fluid. This coelomic fliud contains water, salts, proteins and 4 types of cells namely amoebocytes, mucocytes, circular cells and chloragogen cells. 

There are three types of muscles found in human body, namely skeletal muscle, smooth muscle and cardiac muscle. Skeletal muscles are also called as striated muscles. They are attached to the bone and helps in the movement of skeleton. These muscles are voluntary muscles as they are under voluntary control of somatic nervous system. Examples of skeletal muscle are muscles of arms and legs, muscles of abdomen and back. Smooth muscles are involuntary muscles as they are not controlled voluntarily. They are also called as unstriated muscles as they do not have stripes appearance as in case of skeletal muscle. Examples of smooth muscles include walls of stomach, oesophagus, bronchi and iris. Involuntary smooth muscle of iris helps to adjust pupil size. Cardiac muscles are found only in the walls of the heart. These are involuntary muscles.

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.

If a live earthworm is pricked with a needle on its outer surface without damaging its gut, the fluid that comes out is coelomic fluid because coelomic fluid lies between body wall and alimentary canal. Earthworms are helpful to man as bait for fishing and loosen the soil for roots to grow. A earthworm’s wastes help to fertilize the soil.

In Pheretima two pairs of testes sacs are situated in the 10th and 11th segments. Each testes sac of the 10th segment encloses a testes and a seminal funnel. Each testes sac of the 11th segment encloses a testes, a seminal vesicle and a seminal funnel. 

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 intestine of an earthworm has a peculiar fold of tissue that forms a pocket in the intestine that is visible when viewing a cross section. This space, which runs almost the whole length of the body dorsally is known as the typhlosole and it serves to increase the surface area of the intestine for absorption.

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 break down of detritus into smaller particles by earthworm is known as fragmentation.

Clitellum - secretes cocoon during breading season of earthworm. Gizzard -grinding of food particles. Setae help in locomotion. Typhlosole increases the absorption area in intestine

Thigh muscles are skeletal muscles that are striated and voluntary.

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.