Short Questions and Answers
One Mark Questions with Answers
1. Sebum oil is secreted by
(a) sweat glands
(b) mucous glands
(c) sebaceous glands
(d) cardiac glands
Answer: (a) sweat glands
2. Endometrium is the cellular innermost layer of
(a) blood vessels
Answer: (a) blood vessels
3. Mammary glands are
(a) modified sweat glands
(b) endocrine glands
(c) sebaceous glands
(d) alveolar glands
Answer: (a) modified sweat glands
4. Tunica albuginea covers
Answer: (a) testis
5. Horn of Rhinoceros or snout are produced by
(a) stratum corneum
Answer: (a) stratum corneum
6. Where would you find a mast cells?
(a) adipose tissue
(b) areolar tissue
(c) yellow fibrous tissue
(d) white fibrous tissue
Answer: (b) areolar tissue
7. Which of the following cells secrete histamine in areolar tissue?
(d) mast cells
Answer: (d) mast cells
8. Name the substance involved in allergic and inflammatory reactions
Answer: (a) histamine
9. Fibrous tissue which connects the two bones is
(a) adipose tissue
(c) connective tissue
Answer: (d) ligament
10. The tissue which connects bone with muscle is known as
(b) adipose tissue
(d) fibrous tissue
Answer: (a) tendon
Two Marks Questions with Answers
1. Differentiate between neuron and neuroglia.
Answer: Neuron possesses two types of processes axon and dendron while neuroglia have one type of several processes. Neurons form synapse while neuroglia do not form synapse. Neuron conduct the nerve impulses while neuroglia form a packing around the nerve cells in the central nervous system. Some neuroglia cells are phagocytic in nature. Some of the cells act as scavengers.
2. What are oligodendrocytes?
Answer: These cells have rounded nucleus. The cytoplasm is rich in mitochondria, microtubules and glycogen. They have fewer and shorter cell processes. They occur in two distinct areas near the medullated nerve fibres and near the surfaces of the stomata of neurons. Oligodendrocytes form myelin sheaths around the axons that lie with the central nervous system.
3. What is synapse?
Answer: Synapse is a site of junction between terminal arborizations of axon of one neuron and the dendrites of another neuron. The fibres however do not meet their cell membranes remaine separated by a microscopic gap. Each neuron receives an impulse through its dendrites and passes it on to the next neuron through synapse. A fresh impulse is setup in the dendrites at the synapse with the help of chemicals called neurotransmitters such as acetylcholine produced by the secretory vesicles of the synaptic knobs.
4. Differentiate between axon and dendrite.
Answer: Axon is single per neuron while dendrite may be one or many per neuron. Axon has neurofibrils but no Nissl’s granules while dendrite has both neurofibrils and Nissl’s granules. Axon is long and of uniform diameter while dendrite is short and tapering. Axon is branched at the distal end only whereas dendrite is much branched, practically all along. Axon conducts impulse away from the cyton while dendrite or dendron conducts impulse towards the cyton.
5. What are Synovial membranes?
Answer: Synovial membranes line the cavities of the joints. Like serous membranes, they lie in structures that do not open to the exterior. Unlike mucus, serous and cutaneous membranes, they do not contain epithelium and are therefore not epithelial membranes. They are composed of loose connective tissue with elastic fibres and varying amount of fat. Synovial membrane secrete synovial fluid which lubricates the ends of bones as they move at joints and nourishes the articular cartilages covering the bones that form the joints.
Three Marks Questions with Answers
1. Differentiate between blood and lymph.
Answer: Blood consists of plasma, erythrocytes, leucocytes and platelets while lymph consists of plasma and leucocytes. Blood is red in colour due to the presence of haemoglobin in erythrocytes whereas lymph is colourless as haemoglobin is absent. Glucose concentration is less in blood while glucose concentration is higher in lymph. Amount of carbon dioxide and other metabolic waste is normal in blood whereas amount of carbon dioxide and other metabolic wastes much more in lymph. Blood carries materials towards and away from the tissue, therefore, it acts as a vehicle, while lymph transfers materials from the blood to the body cells and vice versa therefore it acts as a middleman.
2. Differentiate between myelinated nerve fibres and non myelinated nerve fibre.
Answer: Medullary sheath is present in myelinated nerve fibres whereas medullary sheath is absent in non myelinated fibre. Myelinated nerve fibres appear white in fresh state while non myelinated nerve fibres appear grey in fresh state. Nodes of Ranvier are present at intervals in myelinated nerve fibres while nodes of Ranvier are absent in non myelinated nerve fibres. Collateral nerve fibres are present in myelinated nerve fibres while collateral nerve fibres are absent in non myelinated nerve fibres. Myelinated nerve fibres carry impulses faster than non medullated nerve fibres.
3. Mention the functions of epithelia.
Answer: They protect the underlying tissues from mechanical injury, entry of germs, harmful chemicals and drying up. Epithelia check the absorption of harmful or unnecessary materials. Epithelia of uriniferous tubules, stomach and intestine is absorptive. Ciliated epithelia serve to conduct mucus or other fluids in the ducts they line. The epithelia of uriniferous tubules are specialized for urine formation for excretion. Sensory epithelia of sense organ help to receive various stimuli from the atmosphere and convey them to the brain. When epithelia are injured, they regenerate more rapidly than other tissues and thus facilitate rapid healing of wounds.
4. Mention some of the functions of RBCs.
Answer: Haemoglobin of RBCs readily combine with oxygen to form oxyhaemoglobin. In the tissues oxyhaemoglobin readily gives up its oxygen. This oxygen is used for oxidation of food. RBCs also participate in transporting carbon dioxide from tissues to lungs. Carbon dioxide combines with potassium carbonate of the red blood corpuscles to form potassium bicarbonate in the presence of an enzyme carbonic anhydrase. Carbon dioxide also combines with the amino group of the haemoglobin of red blood corpuscles to form carbamino haemoglobin. Moreover, the hemoglobin is an excellent acid base buffer which is largely responsible for maintaining the pH of blood. Acidity of blood results hemoglobin to carry less oxygen.
5. Differentiate between RBCs and WBCs.
Answer: RBCs are smaller, more numerous and longer lived cells than WBCs. WBCs are larger, fewer short-lived cells than erythrocytes. RBCs have a fixed form. RBCs of men are circular, biconcave and enucleated. WBCs are rounded but can change their shape. RBCs occur only in blood vessels while WBCs can escape from capillaries into the tissues. RBCs loose cell organelle during development while WBCs retain cell organelles. RBCs have haemoglobin while WBCs lack hemoglobin. RBCs carry oxygen and carbon dioxide while WBCs act as soldiers and scavengers.