ICSE Set Qa1 Year Icse Biology99 Qa1.php Biology Exam Paper for students online

Biology - 1999 ( I.C.S.E)
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  SECTION-A   (40 Marks)
(one Hour and a Half)

Compulsory :Answer all parts in the Section.

Q 1(b)complete the following statements (i) to (vi) by choosing the correct alternative from those given brackets:
(i) The protective covering of lungs is the (pericardium, pleura, diaphragm).
(ii) Bacteria found in the nodules of leguminous plants are (saprophytic,parasitic, symbiotic)in nature .
(iii)The gaseous pollutant which causes acid rain is (carbon monoxide, Carbon dioxide, Nitrogen  dioxide).
(iv) The valve present between the left atrium and the left ventricle is the (tricuspid valve, bicuspid valve, semiluar valve).
(v) The blood vessel supplying blood to the kidney is the (renal ) vein, renal artery, dorsal aorta).
(vi) which of the following is an insecticide? (Phenol, DDT, carbolic acid)
Ans. 1(b)
i) The protective covering of lungs is the pleura .
ii) Bacteria found in the nodules of leguminous plants are symbiotic in nature .
iii) The gaseous pollutant which causes acid-rain is Nitrogen dioxide .
iv) The value between the left atrium and left ventricle is the bicuspid valve.
v) The blood vessel supplying blood to the kidney is the renal vein .
vi) D.D.T. is an insecticide .

Q 1(c) (i) State whether the following statements are True or False:
1.Deafness is caused due to the rupturing of the pinna.
2.Penicillin obtained from Penicillium notatum is an antibody .
3.The  percentage  of oxygen in ins pired air is 16.4.
4.cells that have lost their  water content are said to be deplasmolysed.
5.Photosynhesis result in loss of the dry weight of the plant .
6.Xylem is the water conducting tissue in plants .

(ii) Rewrite  the false statement from 1 to 6 above in their correct form by changing  the first or the last word only .
Ans.1 (c)
i) False
ii) True
iii) False
iv) False
v) False
vi) True

Q 1(d)  Complete the following table by filling in the blank space numbered1 to 6:

Ans.1 (d)
1. It is the place where most distinct image is formed .
2. Vacuole .
3. Semi niferous tubules .
4. Helps in the transport of gases .
5. A staked form of thylakoid.
6. Urethra

Q 1 (e) Given below is the diagram of the Human Ear. Study the same and then answer the question that follow:

(i) what role does the ear drum play in hearing ?
(ii) What common term is given to the parts labeled A, B and E?
(iii) Would there be any difference if these three parts mentioned in 'ii' above were replaced  by one big one? Why?
(iv) Give the biological term for the parts mentioned in 'iv' above.
(vi) State the functions of the ear.
Ans.1 (e)
i) Ear drum vibrates with the sound waves frequently .
ii) Ear ossicles .
iii) Yes, these three structures can be replaced by a big structure known as Ear ossicles . And there will be no difference because ear ossicles transmits the vibrations to internal ear .
iv) Part-C: Semicircular canals
Part-D: Cochlea
v) Perilymph .
vi) Ear plays a very important role in hearing. Semi-circular canals, utricle and saccule of membranous labyrinth are the structures of equilibrium.

Q 1(f) Given below is a simple diagram of the human kidney cut open longitudinally . Answer the following questions :

1. Give the definition of excretion .
2. Name the units of kidney .
3. Why does the cortex of the kidney show a 'dotted' appearance ?
4. Mention two functions of the kidney .
5. Write two differences in the composition of the blood flowing through blood vessels A and B.
Ans.1 (f)
1. Excretion :- It is actually the removal of wastes especially nitrogenous wastes from the body
2. Nephron
3. Because it contains numerous complex structures known as Nephrons .
4. Kidney removes excess of water from body . Kidney removes nitrogenous wastes like urea , urine etc. from the body .
5. A is Renal vein . It carries deoxygenated blood .
    B is Renal artery . It carries oxygenated blood .  

Q 2 (a) The apparatus given below was set up to demonstrate a particular process occurring in plants . Study the same and then answer the questions that follow :

(i) Name the process .
(ii) What is the object of the experiment ?
(iii) Why is soda lime placed in the tube ?
(iv) What change , if any, would you observe in the lime water in Flask A and in Flask B ? In each case give a reason for your answer .
(v) Mention one precaution that should be taken to ensure more accurate results .
(vi) Give an overall balanced chemical equation to represent the process .
Ans. 2(a)
i) Respiration
ii) Object of the experiment :- To prove that carbon dioxide is released in the respiration of green plants .
iii) Soda lime absorbs CO₂ present in air .
iv) Lime water in Flask A turns milky indicating that  CO₂ must have been released by the plant and this CO₂ turns the lime water milky .
Lime water in Flask B remains clear , because air passing through B is free of CO₂ .
v) Precaution :- Ensure that the bell jar stands on a flat plate smeared with vaseline to prevent leakage of air .
vi) C₆ H₁₂ O₆ + 6O₂ ------ 6CO₂ + 6 H₂O

Q 2 (b) Briefly describe the functions of the following :
(i) Epiglottis
(ii) Scrotum
(iii) Alveoli
(iv) Placenta
Ans. 2(b)
(i) Epiglottis - It is the flap  like region over glottis . It helps to open and close the glottis .
(ii) Scrotum - It is the region where testes lie. It maintains the temperature of testes 2º lower than the internal body temperature  (iii) Alveoli - It is the respiratory unit in the lung of a man .
(iv) Placenta - All the nutritive elements from the maternal blood pass into the foetus through the placenta .      

Ans. 3 (a)

(i)

(ii) Thyroxine
It increases the metabolic rate of the body. and thus , increase heat production and maintain basal   metabolic rate (B  M  R )
(iii) If there was hyposecretion of this gland , a child would suffer from Cretinism .
(iv) Contraction and relaxation of diaphragm plays a very important role in inspiration and expiration .

Q 3(b) Mention one point of difference between the following on the basis of what is given in brackets .
i) Respiration and Photosynthesis (Gas released )
ii) Cerebrum and Cerebellum (Function)
iii) Antibody and Antibiotic (Source)
iv) Red blood corpuscle and White blood corpuscle (Structure )
Ans. 3(b)
i) In respiration CO₂ gas is released while in photosynthesis O₂ gas is released .
ii) Cerebrum is mainly concerned with intelligence , memories etc.
Cerebellum maintains posture and equilibrium .
iii) Antibody - These are the proteinaceous substances which are produced inside the body when stimulated by an antigen .
Antibiotic - It is secreted by living-beings like bacteria and act against the other micro-organism to check its growth .              
iv) Red blood corpuscle are nucleated , oval , and biconvex in fishes , amphibians , reptiles and birds , while R.B.C of all adult mammals are enucleated .
White blood corpuscle are amoeboid in shape with colourless cytoplasm and a definite nucleus . They can change their shape like amoeba .

Q 4 (a)

The diagram given alongside represents an experimental set up to demonstrate a vital process .  Study the same and then answer the questions that follow : i) Name the process . ii) Define the above named process . iii) What would you observe in he experiment can be set up after an hour or so ? iv) What control experiment can be set up for the above experiment ?

v) Keeping in mind the root hair cell and its surrounding , name the part that corresponds to (1) Concentrated sugar solution (2)Parchment paper and (3) Water in the beaker
vi) Name any other substance that can be used instead of parchment paper in above experiment .
vii) Mention two advantages of this process to the plant .
Ans 4(a)
(i) Osmosis
(ii) Osmosis is the diffusion of water from its pure state or dilute solution into a solution or stronger solution when the two are separated by a semipermeable membrane .
(iii) Rise in the level of sugar solutions will be observed .
(iv) Take a U-shaped tube . Fix S.P.M in the centre of it. One arm of it is filled with sugar solution while the other arm is filled with water . After some time water starts moving to sugar solution showing the process of osmosis .
(v) 1. Concentrated sugar solution - Cell sap of root hair cell
2. Parchment paper- Semipermeable membrane of root hair cell .
3. Water in the beaker- Surrounding
(vi) Animal bladder
(vii) 1.Entry of soil water into root is carried out by osmosis .
2. Osmosis performs cell to cell movement of water .

Q 4(b) (i) What is meant by 'reflex action ' ?
(ii) State whether the following are simple reflexes , conditioned reflexes , or neither of the two :
1. Sneezing
2. Blushing
3. Contraction of pupil
4. Lifting up a book
5. Knitting without looking
6. Sudden application of brakes without thinking .

Ans. 4(b)
i) Reflex action : It is a spontaneous automatic mechanical response to a stimulus without the will of animal .
ii) 1. Sneezing : Neither of two
2. Blushing : Neither of two
3. Contraction of pupil : Simple reflex
4. Lifting up a book : Neither of two
5. Knitting without looking : Simple reflex
6. Sudden application of brakes without thinking : Conditioned reflex .

Q 5 (a) The figures given below are cross sections of blood vessels.

(i) Identify the blood vessels A , B and C.
(ii) Name the parts labeled 1-4
(iii) Mention two structural differences between A and B .
(iv) Name the type of blood that flows (a) through A , (b) through B.
(v) In which of the above vessels referred to in (iv) above does exchange of gases actually take place?
Ans. 5 (a)
(i)

(ii)

(iii) The walls of arteries are thick and muscular . They have smaller lumen while the walls of veins are thin , having fever muscle fibres . The lumen of the veins is larger .

(iv) Oxygenated blood flows through A
Deoxygenated blood flows through B

(v) Pulmonary arteries

Q 5 (b) Match Column A with the most appropriate term in Column B . Rewrite the correct matching pair.

Ans.5(b) 1. Liquid part of blood without corpuscles is known as plasma .
2. The clear front part of the eye is Cornea .
3. Place where carbon dioxide leaves the blood is known as Alveolus
4. The liquid squeezed out of blood during clotting is Serum .
5. The spreading of particles by mixing is diffusion .
6. Abscess contains pus .
7. Bronchiole is the small air tube .
8. Iris is the pigmented circular area seen in the eye .

Q 6 (a) The diagram given below represents a defect of vision of the human eye :

(i) Name the defect .
(ii) What is the effect of this defect on man ?
(iii) Mention two causes for this defect .
(iv) How can this defect be rectified ?
(v) Draw a neat labeled diagram to show that how this defect can be rectified .
(vi) What is the nature of the image that falls on the retina of a normal eye ?
Ans. 6 (a)
(i) Hypermetropia
(ii) The person has difficulty in seeing near object .
(iii) Eyeball is too short .
Light rays converge at a point behind the retina resulting in a blurred image .
(iv) By using Convex lens .

(v)

Q 6(b) A candidate in order to study the importance of certain factors in photosynthesis took a potted plant and kept it in the dark for over 24 hours . Then in the early hours of the morning she covered  one of the leaves with black paper in the centre only. She placed the potted plant in the sunlight for a few hours , and then tested the leaf which was covered with black paper for starch .
i) What aspect of photosynthesis was being investigated ?
ii) Is there any control in this experiment ? If so , state the same .
iii) Why was the plant kept in the dark before the experiment ?
iv) Describe step by step how the candidate proceeded to test the leaf for the presence of starch .

Ans. 6(b) (i) That sunlight is necessary for photosynthesis
(ii) Yes , there is another control experiment for the same .
Experiment
1- Destarch the plant .
2- Fix a strip of black paper in the center of a leaf .
3- Expose the entire plant to sunlight for a few hours .
4- Detach the leaf , which was partly covered and perform starch test .
Results : Covered portion is brown
while the rest of the leaf is blue , showing the presence of starch
(iii) The plant was kept in the dark so that all the starch can be removed from the plant .
(iv) she detached the leaf which was partly covered with the black paper and perform the starch test. Regions of the leaf that was under the black paper stains brown that means that part has no starch. While the rest of leaf turns blue . That means rest of the leaf has prepared starch .

Q 7(b) Define the following terms :
i) Hormone
ii) Ultrafiltration
iii) Antiseptic
iv) Transpiration .

Ans.7(b) (i) Hormone :- is the chemical substance which act as chemical messenger .
(ii) Ultrafiltration:- is the process of filtration of glomerulus filtrate in Bownson's capsule .
(iii) Antiseptic :- protect the body against infection of germs
(iv) Transpiration :-is the loss of water vapours from stomata of leaves .