Q 1. What does growth ring indicates?
Ans. Since one growth ring is formed in one year, a count of the rings at the base of trunk indicates the age of trees at the time it was cut.
Q 2. What is the function of heart wood?
Ans. In most species the heartwood accumulates a variety of chemicals such as resins, oils, gums and tannins. These provide a resistance to decay and insect attack for example in red cedar and conifers.
Q 3. What are sleep movements?
Ans. Bean plants and some members of legume family lower their leaves in the evening and raise them in the morning. These are known as sleep movements.
Q 4. What is Nyctinasty?
Ans. The nyctinastic movements are shown by the organs in response to external stimuli leading to differential growth. These are due to turgor and growth changes.
Q 5. What is cartilage?
Ans. Cartilage is much softer than bone. It is a form of connective tissue. It covers ends of the bone at the joint, and also support the flexible portion of nose and external ears. No blood vessels penetrate into cartilage.
Q 6. In how many categories joints are classified? Name them.
Ans. Joints are classified on the basis of the amount of movements allowed by them, into three categories:
- Immovable joints
- Slightly movable joints
- Freely movable joints
Q 7. What is sciatica?
Ans. It is characterized by stabbing pain radiating over the course of sciatic nerve results due to injury of proximal sciatic nerve, which might follow a fall, a herniated disc or improper administration of an injection into the buttock.
Q 8. How many steps are involved in repairing of broken bones? Name them.
Ans. The repair process of a simple fracture takes place in four phases:
- Haematoma formation
- Callus formation
- Bony callus formation
- Remodelling
Q 9. Why heart muscles are known as cardiac muscles?
Ans. Cardiac muscles are actually the muscles of heart. They constitute most of the mass of the heart walls. These muscles are also striated and involuntary. Therefore, heart muscles are known as cardiac muscles.
Q 10. What are digitigrades?
Ans. The mammals which tend to walk on their digits only are called digitigrades. They run faster than plantigrade animals e.g., rabbit, rodents etc.
Q 11. What are cross bridges?
Ans. The heads of myosin are called cross bridges which make links with actin during muscles contraction.
Q 12. What do you understand from "Rigor Mortis"?
Ans. After death, the amount of ATP in the body falls, Under these circumstances the bridges cannot be broken and so they remain firmly bound. This results in the body becoming stiff, a condition known as Rigor Mortis.
Q 13. Define sacromere.
Ans. A sacromere is the region of a myofibril between two successive Z-lines and is the smallest contractile unit of muscle fibre.
Q 14. What are chondrocytes?
Ans. The living cells of cartilage are called chondrocytes. These cells secrete flexible, elastic, non-living matrix collagen that surrounds the chondrocytes.
Q 15. What is spondylosis?
Ans. It is the disease, which causes immobility and fusion of vertebral joint.
Q 16. What is hydro-skeleton or hydro-static skeleton?
Ans. Animals may have a fluid filled gastrovascular cavity or coelom which can act as hydro-skeleton or hydro-static skeleton. Hydro-static skeleton provides support and resistance to the contraction of muscles so that motility results.
Q 17. What is the hyaline cartilage?
Ans. It is the most abundant type of cartilage in human body. It is found at the movable joints.
Q 18. What provides support in plants and animals?
Ans. The collenchymatous cells in plants give support to the baby plants and sclerenchymatous cells to the adult plants. In animals muscles, cartilage and bones provide support.
Q 19. What is turgor pressure?
Ans. The living cells of epidermis, cortex and pith take in water by osmosis. An internal hydrostatic pressure called turgor pressure develops, which keeps them rigid, resistant to bending and maintain the turgidity.
Q 20. What is Bundle cap?
Ans. In the stem of some plants, for example, sunflower, the vascular bundles are strengthened by additional sclerenchyma fibers, which form bundle cap.
Q 21. What is tonoplast?
Ans. The membrane that bounds vacuole is called tonoplast which contains a number of active transport systems that pump ions into the vacuoles.
Q 22. What are fibers or tracheids?
Ans. These are long and cylindrical and they may exist in solid bundles in xylem or as bundle caps.
Q 23. What are sclereids?
Ans. These are shorter than fibers and are found in seed coats and nutshells and provide protection.
Q 24. What are vessels or trachea?
Ans. Long tubular structures, join end to end to form long water conducting pipe in xylem.
Q 25. Define secondary growth?
Ans. Growth due to lateral meristem or cambium is called secondary growth.
Or
An increase in plant growth due to the activity of vascular cambium is called secondary growth.
The result of secondary growth is most evident in woody, perennial plants like trees, shrubs and vine.
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Q 26. Which meristems are involved in secondary growth?
Ans. Secondary growth occurs due to cell division in:
- Vascular cambium
- Cork cambium
Ans. As trees grow older only few annual growth rings are active in conduction at one time. The active portion is called sapwood. The inactive non-conducting wood is called heartwood.
Q 28. What is callus or wood tissue?
Ans. An important function of the cambium is to form callus or wood tissue on or over the wound. Soft parenchymatous tissues are rapidly formed on or below the damaged surface of stems and roots. The callus unites the branches during budding and grafting.
Q 29. What is difference between animal and plant movements?
Ans. Animals move in response to external stimuli by motion, similarly plants also show movements. Animals change their location in response to stimulus. Plants are fixed therefore they change their growth pattern.
Q 30. What are main types of movements in plants?
Ans. There are two types of movements:
Autonomic movements
Growth movements
Q 31. What are autonomic movements. Also give their main types.
Ans. Autonomic movements are spontaneous movements due to internal causes. Autonomic movements are of three types:
- Tactic movements
- Turgor movements
- Growth movements
Ans. These are the movements of an entire cell or organism i.e. locomotion due to external stimulus. The tactic movements may be positive if it is towards the stimulus or negative if it is away from the stimulus.
Q 33. What is phototactic movement?
Ans. It is a movement in response to stimulus of light. The best example of positive tactic movements is the passive movements of chloroplast due to cyclosis. This movement helps the chloroplast to absorb maximum light for CO2 fixation.
Q 34. What is chemotactic movement.
Ans. The movements in response to stimulus of chemicals is called chemotactic movements. The movements shown by sperms of liver-worts, mosses, ferns towards archegonia in response to stimulus of nucleic acid released by the ovum are such examples.
Q 35. What is turgor movements?
Ans. Turgor movements is due to differential changes in turgor and size of cells a result of gain or loss of water. Rapid movements of leaflets in " touch me not" plant and sleep movements of the plants fall under this category of movements.
Q 36. What are growth movements?
Ans. Growth movements are due to unequal growth on two sides of plants organs like stem, root, tendrils, buds etc.
Q 37. Define epinasty.
Ans. It is shown by leaves, petals etc. The upper surface of leaf in bud condition shows more growth as compared with the lower surface. This leads to opening of buds.
Q 38. Define hyponasty.
Ans. If growth in the lower surface of the leaf in bud condition is more than that of the upper surface than the bud will remain closed.
Q 39. Define nutation.
Ans. The growing tip of young stem moves in zig zag fashion due to alternate changes in growth on opposite side of the apex. This mode of growth is called nutation.
Q 40. What are tropic movements?
Ans. It is the movement in curvature of whole organ towards or away from stimuli such as light, gravity and touch.
Q 41. Define phototropism.
Ans. It is the movement of part of the plant in response to stimulus of light and is caused due to differential growth of a plant part like stem or root.
Q 42. Define thigmotropism.
Ans. It is the movement in response to stimulus of touch, for example climbing vines. When they come in contact with some solid object, the growth on the opposite side of contact increases and the tendril coils around the support.
Q 43. Define chemotropism.
Ans. The movement in response to some chemicals is called chemotropism. The hyphae of fungi are chemotropic.
Q 44. Define hydrotropism.
Ans. The movement of plant parts in response to stimulus of water is called hydrotropism. Roots show positive hydrotropism and shoots show negative hydrotropism.
Q 45. Define geotropism or gravitropism.
Ans. It is the response to gravity. Roots display positive geotropism and shoots show negative geotropism.
Q 46. What are nastic movements?
Ans. These are the non-directional movements of parts of plant in response to external stimuli.
Q 47. Define photonasty.
Ans. The principal stimulus is the photoperiod. Flowers, open and close due to light sensitivity.
Q 48. Define thermonasty.
Ans. It is due to temperature. The flowers of tulip close at night because of rapid growth in the lower side by upward and inward bending of the petals.
Q 49. Define haptonastic movements?
Ans. It occurs in response to contact e.g., the action of the Venus fly trap.
Q 50. What is skeleton?
Ans. The skeleton is tough and rigid framework of the body of animals which provides protection, shape and support to the body organs.
Q 51. What are different types of skeleton?
Ans. There are three main types of skeleton in animals:
- Hydrostatic Skeleton
- Exoskeleton
- Endoskeleton
Q 52. Define exoskeleton.
Ans. An exoskeleton is hardened outer surface to which internal muscles can be attached.
Q 53. What is the composition of of exoskeleton?
Ans. It is composed of two layers. The epicuticle is the outermost layer and is made up of waxy lipoprotein. The bulb of exoskeleton is below the epicuticle and is called procuticle which is composed of chitin, tough, leathery, polysaccharide and several kinds of proteins.
Q 54. What is moulting or ecdysis?
Ans. When arthropods have to grow they need to shed exoskeleton periodically and replace it with one of the larger size. This process is known as Ecdysis or moulting.
Q 55. What is endoskeleton?
Ans. The skeleton that lies internally to the muscles is called endoskeleton. It provides support, shape, protection and locomotion.
Q 56. What is the composition of endoskeleton?
Ans. The endoskeleton is primarily made up of two types of tissues.
- Bones
- Cartilage
Q 57. What do you know about compact bone?
Ans. Compact bone is dense and strong and provides an attachment site for muscle.
Q 58. What are the characteristics of spongy bone?
Ans. Spongy bone is light,rich in blood vessels, and highly porous. The cavities of spongy bone contain bone marrow where blood cells are formed.
Q 59. Name the cells associated with bone?
Ans. There are three types of cells associated with bone:
- Bone forming cells (Osteoblasts)
- Mature bone cells (Osteocytes)
- Bone dissolving cells (Osteoclasts)
Q 60. What is fibro cartilage?
Ans. It has matrix containing bundles of collagen fibres. It forms an external pinnae of ear and epiglottis.
Q 61. What is axial skeleton?
Ans. The skeleton that includes the skull, the vertebrae, and the ribs and the sternum is called axial skeleton.
Q 62. Name the bones of cranium.
Ans. Parietal and temporal are paired bones, whereas frontal, occipital, sphenoid and ethmoid are unpaired bones.
Q 63. Name the bones of facial region?
Ans. The paired facial bones are maxilla, zygomatic, nasal, lacrimal, palatine and inferior concha. The unpaired facial bones are mandible and vomer.
Q 64. What is vertebral column?
Ans. Vertebral column extends from skull to the pelvis to form backbone, which protects the spinal cord. It consists of 33 vertebrae. The vertebrae are named according to their location in the body, viz, cervical, thoracic, lumbar and pelvic.
Q 65. What is sacrum?
Ans. Sacrum is formed by the fusion of anterior five vertebrae present in the pelvic region.
Q 66. What is coccyx?
Ans. Coccyx is formed by the fusion of four posterior vertebrae present in the pelvic region.
Q 67. Why lower two pairs of ribs are called "floating ribs"?
Ans. The lower two pairs of ribs are called floating ribs because they do not attach with the sternum.
Q 68. What is appendicular skeleton?
Ans. The skeleton that consists of pectoral girdle and appendages(fore limbs) and pelvic girdle and appendages(hind limbs) is called appendicular skeleton.
Q 69. What does pectoral girdle comprise?
Ans. Pectoral girdle attaches the arms to the trunk. It comprises scapula, supra-scapula and clavicle. The clavicle connects scapula with sternum.
Q 70. Name different bones of fore limb.
Ans. The fore limb consists of humerus, radius, ulna, 8 carpals, 5 metacarpals and 14 phalanges.
Q 71. What are important features of pelvic girdle?
Ans. Pelvic girdle attaches the hind limb to the vertebral column. It consists of two coxal bones. Each is formed by the fusion of three bones ilium, ischium and pubis.
Q 72. Name different parts of hind limb.
Ans. The hind limb consists of one femur, 2 tibia + fibula, 8 tarsals, 5 metatarsals and 14 phalanges.
Q 73. What different classes of joints on the basis of structure?
Ans. Joints are also classified on the basis of structure:
- Fibrous Joints
- Cartilaginous Joints
- Synovial Joints
Q 74. What are hinge joints?
Ans. The joint that allows the movements in two directions is called hinge joint. These are at elbow and knee.
Q 75. What are ball & socket joints?
Ans. These joints allow movement in several directions. Such joints have at least two pairs of muscles present perpendicular to each other. Hip joint and shoulder joint are the examples of ball and socket joints.
Q 76. What is cleft palate?
Ans. Cleft palate is a condition in which palatine processes of maxilla and palatine fail to fuse.
Q 77. What is arthritis?
Ans. Arthritis covers over 100 different types of inflammatory or degenerative diseases that damage the joints. It results in pain, stiffness, of the joints. Friction is increased.
Q 78. What is osteoporosis?
Ans. Osteoporosis is a condition of brittle and fragile bones. In this case bone mass is reduced and chemical composition of the matrix remains normal. Osteoporosis mostly occurs in aged women, which have decreased oestrogen level.
Q 79. What is osteomalcia?
Ans. Osteomalcia (soft bone) includes a number of disorders in which the bone receive inadequate minerals. In this disease calcium salts are not deposited and hence bones soften and weaken. Weight bearing bones of legs and pelvis bend and deform.
Q 80. What is rickets?
Ans. Rickets is a disease in children with bowed legs and deformed pelvis. It is caused by deficiency of calcium in diet or vitamin D deficiency.
Q 81. What is disc-slip?
Ans. Severe or sudden physical trauma to spines fro example from bending forward while lifting a heavy object may result in herniation of one or more disc. The herniated or slipped disc usually involves rupture of annulus fibrosus followed by protrusion of the spongy nucleus pulposus.
Q 82. What is closed reduction?
Ans. In closed reduction the bone end is coaxed back to their normal position by physician's hand.
Q 83. What is open reduction?
Ans. In open reduction surgery is performed and the bone ends are secured together with pins or wires.
Q 84. What are muscles?
Ans. Many multicellular animals have evolved specialized cells muscles fro movement. They contain numerous filaments of special proteins, actin and myosin.
Q 85. Name different types of muscles in vertebrates.
Ans. The vertebrates possess three kinds of muscles:
- Smooth muscles
- Skeletal muscles
- Cardiac muscles
Q 86. What are smooth muscles?
Ans. Smooth muscles are long and spindle shaped with each containing a single nucleus. It has no striations. It is not under the voluntary control. These muscles are found in the blood vessels, digestive tract and many other organs.
Q 87. What are cardiac muscles?
Ans. These are muscles of the heart. Heart muscles is composed of chains of single cell, each with its own nucleus. The chain of cells is organized into fibres that are branched and interconnected. The cardiac muscles are striated an involuntary.
Q 88. What are skeletal muscles?
Ans. The muscles that are attached with the skeleton and associated with the movement of bones are called skeletal muscles. The skeletal muscles are voluntary and striated.
Q 89. What are tendons?
Ans. Generally each end of entire skeleton muscle is attached to bone by a bundle of collagen, non-elastic fibres known as tendons.
Q 90. What is muscle fibre?
Ans. Each muscle consists of muscle bundles, which are further composed of fibres or cells. Each muscle fibre is long cylindrical cell with multiple oval nuclei arranged just beneath its sarcolemma. Their diameter is 10-100 micro meter.
Q 91. What is sarcolemma and sarcoplasm?
Ans. The cell membrane of muscle cell is called sarcolemma while its cytoplasm is called sarcoplasm.
Q 92. What are myofibrils?
Ans. When viewed in high magnification, each muscles fibre is seen to contain a large number of myofibrils, 1-2 mm in diameter, that run in parallel fashion and extend the entire length of the cell.
Q 93. What are dark and light bands in sarcoplasm?
Ans. The dark bands are called A band because they are anisotropic that is they can polarize visible light. The light bands are called I band are isotropic or non-polarizing.
Q 94. What are H-zone and M-line in A band of sarcomere?
Ans. Each A band has a lighter stripe in its midsection called H-zone (H stands for hele means bright). The H-zone is bisected by dark line called M-line.
Q 95. What is T-system?
Ans. The sarcolemma of muscle fibre cell penetrates deep into the cell to form hollow elongated tube, the transverse tubule or T-tubule. The thousands of T-tubules of each muscle cell are collectively called T-system.
Q 96. What are triads?
Ans. The T-tubule and terminal portion of the adjacent envelope of sarcoplasmic reticulum form triads at regular interval along the length of the myofibril.
Q 97. What is sliding filament model?
Ans. According to this model the thin filament slide past the thick one's so that actin and myosin filaments overlap to greater degree.
Q 98. What is a motor unit?
Ans. All the fibres innervated by a single motor neuron are a Motor Unit and contract simultaneously in response to the action potential fired by the motor neurons.
Q 99. What is other sources of energy for muscle contraction in addition to glucose?
Ans. When more energy is required due to high metabolism, it is provided by another energy storing substances called creatine phosphate.
Q 100. What is muscle fatigue?
Ans. Muscle fatigue is a state of physiological inability to contract. Muscle fatigue results from relative deficit of ATP. Excess accumulation of lactic acid and ionic imbalances also contribute to muscle fatigue.
Q 101. What is tetany?
Ans. Tetany is the disease caused by low calcium in the blood. It increases the excitability of neurons in loss of sensations. Muscle twitches and convulsion occur.
Q 102. What is cramp?
Ans. It is also known as tetanic contraction of entire muscle. It lasts for just few seconds or several hours, causing the muscles to become stretched and painful. It is most common in thigh and hip muscles.
Q 103. What are different parts of skeletal muscle?
Ans. Skeletal muscles has three parts:
- Origin
- Insertion
- Belly
Q 104. What are ligaments and tendons?
Ans. Ligaments attach bone to bone and are slightly elastic and tendons attach muscles to bones and are non-elastic.
Q 105. What are antagonistic arrangement?
Ans. At joint the muscles work against each other by contraction. This relationship is called antagonistic arrangement.
Q 106. What are brachialis & brachioradialis?
Ans. These muscles lie below the biceps brachii. The brachialis is inserted in the ulna, while brachioradialis is inserted in the radius. When these muscles contract the lift ulna and radius and bend the arm at the elbow.
Q 107. What are organs of locomotion in euglena, paramecium and amoeba?
Ans. Euglena moves with the help of flagellum. Paramecium moves with the help of cilia. Amoeba moves by means of pseudopodia.
Q 108. What is effective stroke?
Ans. Five out of nine double fibrils contract or slide simultaneously, cilia bend or shorten. It is called effective stroke.
Q 109. What is recovery stroke?
Ans. The four out of nine double fibril contract and cilia become straight. It is called recovery stroke.
Q 110. What is the type of locomotion in jellyfish and earthworm.
Ans. Jelly fish moves by jet propulsion. Earthworm shows accordion-like movement, in which setae and muscles both are involved.
Q 111. What is mode of locomotion in cockroach?
Ans. The mode of locomotion in cockroach is swift walking but it also takes to flight by its wings.
Q 112. How locomotion occurs in snail and mussels?
Ans. Snails and mussels are mollusks, which crawl or move very slowly by foot.
Q 113. What are tube feet?
Ans. Tube feet are organs of locomotion in starfish.
Q 114. What is swim bladder?
Ans. Buoyancy in the water is maintained by a specialized structure in bony fish called swim bladder.
Q 115. How wriggling occurs in amphibians?
Ans. Amphibians wriggle along the belly on the ground, with the help of segmentally arranged muscles as it swims on land with legs hardly touching the ground when moving deliberately.
Q 116. What is bipedal locomotion?
Ans. Bipedal means that animals walked on hind limbs. Bipedal locomotion freed the front appendages, which become adapted for prey capture or flight in some animals.
Q 117. What is passive flight?
Ans. When birds glide, the wings act as aerofoil. An aerofoil is any smooth surface which moves through the air at an angle to the air stream. The air flows over the wing in such a way that the bird is given lift.
Q 118. What is active flight?
Ans. When little or no support can be gained from the upward air currents, the same effect can be achieved by flapping the wings and is called active flight.
Q 119. What is plantigrade?
Ans. In this mode of locomotion the mammals used to walk on their soles with palm, wrist, and digits all lending to rest more or less on ground, such as monkeys, apes, man and bear etc.
Q 120. What is unguligrade?
Ans. The mammals walk on the tips of toes modified into hoof such as deer, goat. It is the swiftest type of locomotion.
Q 121. What is the cause of muscle cramp?
Ans. It is caused by:
- Low blood sugar
- Electrolytic dapletion
- Dehydration
- Irritability of spinal cord and neurons.
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