Zoology Solved Past Paper 2nd year 2011 Karachi Board


Choose the correct answer for each from the given options:

i) Test Produce:
* Oesterogen
* Progesterone
* Testosterone
* Yolk sac

ii) Anaemia is due to the deficiency of:
* Iron
* Iodine
* Vitamins

iii) Night blindness is caused due to the deficiency of:
* Vitamin K
* Vitamin A
* Vitamin
* C Minerals

iv) The joints of elbow and knee are:
* Sliding joints
* Gliding joints
* Hinge joints
* Ball & Socket joints

v) Skeleton is totally absent in:
* Sponge
* Star fish
* Amoeba
* Insects

vi) The, end of the period of fertility in a human female is:
* puberty
* ovulation
* menses

vii) The study of abnonnalities during embryonic development is:
* Embryology
* Cytology
* Gerontology

viii) Ovulation is initiated by the honnone:
* LH
* Oestrogen
* Progesterone

ix) This gas is responsible for global wanning:
* Oxygen
* Nitrogen
* CO²
* Ozone

x) Goitre is caused by the deficiency of:
* Calcium
* Iron
* Iodine
* Vitamins

xi) Malpighian tubules are the excretory organs of:
* Earthworm
* Hydra
* Planaria
* Cockroach

xii) Acetylcholine is released by:
Axon terminal
* Dendrite terminal
* Node of Ranvier
* Schwan cells

xiii} This element is necessary for muscle contraction:
* Potassium
* Magnesium
* Sodium

xiv) Skull is a part of:
Axial skeleton
* Exoskeleton
* Appendicular skeleton
* Hydrostatic skeleton

xv) Solving problem without tial and error is:
* Habituation
* Classic conditioning
* Latent learning

xvi) The deficiency of insulin may cause this disease:
* Diarrhoea High
* blood pressure
* Diabetes
* Anaemia

xvii) The number of muscles in human body is:
* 300
* 400
* 500
* 600

xviii)The most abundant component of urine is:
* Urea
* Water
* Ammonia
* Uric acid


2.i) Write the types of receptors.
Ans: See on Page # 419.

ii) Differentiate between Nervous Co-ordination and Chemical Coordination.
Ans: See on Page # 409.

iii) Write a note on Epilepsy.
Epilepsy is a endency of recurrent seizures or temporary alteration in one or more functions. The seizures are transisent neurological abnonnalities caused by abnonnal electrical activity In the brain. The seizures may be spontaneous or due to some stimulus such as flashing right The seizures may be generalized or partial. The generalized seizure is characterized by complete unconsciousness, stiff body with twitches or jerks. In partial seizure, there is a momentary loss of consciousness without abnonnal movements. Anticonvulsant dmgs are administrered.

iv) What are Transgenic animals?
The genetically engineered animals in which foreign gene inserted in to eggs before fertilization are known as transgenic animals. The micro-injections of bovine growth~ harmone (bGH) in to eggs of animals is the procedure that is use in fishes, chicken. cows, p:gs. rabbits and sheep to produce bigger and heavier verieties. Transgenic cows has been produced that carries a geRe for the production of human lactoterin in cow milk. The lactoferin has antibacterial activity as well as it transport iron in body. The- dinical trials have been carried out on milk secreted by transgenic goat which contain antithrombin III, for preventirtg blood clot during surgery.

v) Name the parts marked in the diagram



vi) Explain Gene therapy.
Ans: See on Page # 430.

vii) Write a note abnonnal muscle contraction.
W enever the conditio s necessary for a musde contraction are not fully me With its contraction becomes abnormal. Tetany and muscle cramps are the common abnormal muscle con ctions.
1.Tetany: Tetany i!> a sudden involuntary contraction of striated muscle, which is caused by low level of calcium in the blood. It excites neurons which triggers muscle twitching rapidly even before the actin and myosin filaments of a muscle fibre had a chance to return to their nonnal resting condition. Hence the muscle fibres ‘are he d under a constant contraction. Because of a high level of stimulation the calcium ions are not removed from the sarcoplasm and e contractile machinery thus ecp on generating maximum tension. This condition is called etany. Tetany of the respiratory organ ,< ot treated im ediately may prove fa at
2. Cramps: It s also a type of tetanic contraction, whj.cfI.i~ commonly called a musde pull. It usually occurs In a limb’s muscles. It occurs due to dehydration, elecbulyte imbalance or a low blood sugar level, particularty, after a heavy exercise. Sportsmen are more prone to it

viii) Write a note on spermatogenesis.
The process of cell division in which sperms are formed from the germs cells in male gonads (the testes). The germ cell divides mitotically and produces spermatogonia and then into primary spermatocyte. Now each primary spermatocyte divide meiotically into two secondary spermatocyte, which further divides to form four genetically different spermatid that contain haploid chromosomes, which ultimately develop into sperm. It take 10 week to complete process.

ix) Write a brief note on liver as a homeostatic organ.
Liver is a large radish brown glandular organ located in the abdomen just below the diaphragm. It is a metabolic centre therefore it is richly supplied with blood. A sac-like gall bladder is attached with it for the storage of bile secreted by liver. Bile is poured into the duodenum, by a bile duct. Rest of its products are released into the blood throug hepatic vein.
Although liver performs hundreds of functions we are restricting here to some of its main homeostatic functions.
It maintains concentration of glucose in the blood. If glucose concentration increases, it is converted into glycogen and stored here. At the time of shortage of glucose in blood, glycogen is broken down into glucose and supplied to the body. If glycogen store is depleted, then amino acids may converted into glucose by the liver. It removes lipids from the blood either by oxidation or by modification and subsequently stores as fat. It can also synthesizes non-essential amino acids, as well as plasma proteins like prothrombin, fibrin, globulin etc.

x) What is meant by evidences from vestigial organs.
Evidence from Vestigial Organs: The organs have no apparent purpose called vestigial organs.
Examples: Coccyx bone, appendix etc in man.
Movement of pinna of the ears of dogs and horses.

xi) Write a note on Thyroid gland.
Location: The thyroid gland is present at the base of neck.
Structure: It consists of two lobes situated on either side of trachea and is butterfly like. The lobes joined by isthmus.
It’s secretion is called “Thyroxine- which is of two types T3, T.;
It controls rate of body metabolism and physical growth .
It stumulates growth and development in young animals. Deficiency of thyroxine i children causes “Cretinism” which leads to stunted development of man and produce dwarfism and puffed skin. Such persons are called Cretins .
Normal mental activity is controlled by thyroid gland. The atrophy of this causes -Myxedema- in adults which lead to slowness of the metabolism. . .
If more thyroxine is released it causes -Hyperthyroidism- in adults which lead to high metabolism e.g increased heart beat and restlessness of the body and bulging of eyeball, -Exophthalmos-

Due to the deficiency of iodine thyroid gland produces excess thy roxine. The gland may enlarge and apeared as a swelling in the neck called “Goiter”.

xii) What is nuclear energy?
It is obtained from nuclear fules by Nuclear fission. Nuclear fission involves splitting of certain heavy elements into lighther ones. It takes nearty about 7 hours to fission of 1 Kg of nuclear fuel resulting 79 kg as heat at a rate of 300,000 kilowatts.
While combustion of about 3- million kg of coal resulting the 300,000 kilowatts. It results the hazardous effects on enviroment.

xiii) Describe peripheral nervous system.
In human, peripheral nervous system includes thirty-one pair of spinal nerves which connect with the spinal cord. It also includes twelve pairs of cranial or cerebral nerves, which connect directly with the brain. These spinal and cranial nerves further divided into two systems according to their function.
B- Autonomic Nervous System.
C- Somatic Nervous Systel]1.
A- ··Autonomic Nervous System: This system is formed from q special set of peripheral nerves that serve the heart, lungs, digestive tract and other internal organs. It is related to involuntary activity. It can be divided into sympathetic and parasympathetic nervous system.
B- Somatic Nervous System: It includes all nerves that serve the muscular skeletal system and exterior sense organs including those in the skin. This system carries the impulses that we are most conscious of the commands to our voluntary muscles and
the concious sensations from all parts of our bodies.

xiv) Give the names of sexually transmitted diseases and explain anyone.
Sexually transmitted disease are those, that are transmitted from infected partner to a healthy partner during the sexual contact. Few of them are discuss below,
1- Gonorrhea
2- Syphilis
3- Genital Herpes
4- AIDS “(Acquired Immuncr Deficiency Syndrorn)”
Gonorrhea: This disease is caused by Gram positive bacteria names as -Neisseria gonorrhoea-. It mainly affects the musous membrane of urogenital tract. It causes wound in genital tract and infected male experience buming during micturation and thick white dischange from uretra. In female, it infects oviduct and damaged the tube and block it. If this is untreated, lead to infertiltiy in both female and male. The infected mother can transmit the disease to her new bom baby while he or she pass through the birth canal. These babies suffer eye infeGtion. If it is not treated immedia~1y lead to blindness in new bom . ..!his is called as Ophthalmia newnatorurn”.
Ireatment: Is silver nitrate eye drop.

xv) Write a note on reflex action.
Ans: See on page # 448.

xvi) Explain Osmoregulation in terrestrial animals.
Ans: See on Page # 406


3. With the help of labelled diagram, describe the human female reproductive system. .
Ans: See on Page # 424.

4. What is excretion? Describe how does it occur in planarie, earthworm and cockroach.
The removal of nitrogenous waste material and excess salt-and water produced during oxidation of food is called “Excretion”.
Excretion In Planaria: Planaria is free living flat worm and has a developed excretory system. The excretory system consist of longitudinal branching tubules on either lateral side and running along the entire length of animals. Each tubules open to external surface by means of pores. Internally in the mesenchyme each tubule give rise to numerous blind bulb like cells called “flame cells” or “Protonephridia”. The flame cell contain tuft of cilia which beat in the manner of flickering flame.

The water along with ammonia diffuse from the tissue fluid into lumen of flame cell. The ‘beating of cilia propels the fluid into “excretory canal” then this fluid is excreted out through excretory pores. During this movement water is absorbed and remaining fuid i.e.. urine excreted out. Thus flame cell maintain osmoregulation. Some of the fluid is excreted in the gut and removed through mouth along with undigested food.

Excretion In Earthworm: The excretory and osmoregulatory organ of earth worm is called “metanephridia”. They are arranged in segments. The metanephridium is highly coiled tube and surrounded by capillaries. It has two oparings. The internal opening is called “nephrostome” and it contain cilia. The





outer opening is called nephridiopore, that open out side into the skin. Before opening outside each tube dilates to form bladder. By the beating of cilia of nephrostome the coelomic fluid is pumped into
excretory tubule. Some excretory substances are secreted through cells of tubules. Selective reabsorption of useful substances also take place which are taken up by the blood. The urine is emptied in the bladder and then exerted out through nephridiopore.



5. What is evolution? Describe the palaeontology and embryological evidences in support of organic evolution.
Organic evolution is the gradual and orderly development of living organism from simple and unorganized form to complex and organized form.
Evidence from fossa record (Paleontology): A fossil is any trace of life from the past. Fossil record consists of an entire collection of such remains from which paleontologists attempt to reconstruct the biology of the organisms whose remains were left behind.
Example: Archaeopteryx (Archaeo= old, pteryx=wing), fossil bird had lived 150 million years ago. Unlike the modem birds. Archaeopteryx had teeth .a long tail having 20 vertebrae, wings containing movable fingers with claws, All these characteristics show link with reptiles. The teeth of this pigeon/crow sized animal would have been suitable for the capture of insects or other small prey.
So scientists believe that Archaeopteryx is a good evidence of an evolutionary path way leadiaq from reptiles to birds. Evidence from comparative embryology: Detailed comparative embryological study shows similarities between widely separated animals groups though such animals have markedly different. Example: Vertebrates history shows that fishes, salamanders. tortoises, birds, mammals including man had a common ancestor, probably some type of primitive fish, so embryonic development of all these animals provides a window to evolution. Scientists believe that the study of embryonic development provides one of the best tools to understand the evolutionary linkage among animals.

OR Explain Thermoregulation in Mammals.
Ans: See on Page # 438.

Posted on January 4, 2016 in 2nd Year 2011 Karachi Board Past Papers

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