Previous Year Paper year:2012 : ICSE-X-Biology

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ICSE-X-Biology

Previous Year Paper year:2012

with Solutions - page 5

#3-a-iv
Is the cell given above a. plant cell or an animal cell ? Give two reasons in support of your answer as evident from the diagram.
Ans : Plant cell. Because
(1.) Clear distinct cell wall is seen
(2.) Chloroplast clearly seen in. the cytoplasm.
(3.) Centrosome not seen.

#3-a-v
What would you do to bring this cell back to it original condition ?
Ans : Place it on a hypotonic medium or plain water for some time.

#3-b [5]
Differentiate between the following pairs on the basis of what is mentioned in brackets:

#3-b-i
Natality and Mortality (definition)
Ans : Natality - Number of live births per 1000 per year.
Mortality - Number of deaths per 1000 per year.

#3-b-ii
Stoma and Stroma (describe its structure.)
Ans : Stoma - The opening in the stomata through which transpired water and respiratory gases pass.
Stroma - It is the part/region in the chloroplast where dark reaction of photosynthesis takes place.

#3-b-iii
Acromegaly and Cretinism (symptoms)
Ans : Acromegaly - Overgrowth of certain parts of body like cheek bones etc. due to oversecretion of growth hormone in adults.
Cretinism - Dwarfism and mental retardation due to undersecretion of thyroxine in children.

#3-b-iv
Transpiration and Guttation (structures involved)
Ans : Transpiration - Stomata/cuticle/lenticels.
Guttation - Hydathodes.

#3-b-v
Diabetes mellitus and Diabetes insipidus (reason) cause).
Ans : Diabetes mellitus - Undersecretion of insulin due to which level of glucose increases in blood.
Diabetes insipidus - Undersecretion of Antidiuretic hormone due to which reabsorption of water from kidney tubules becomes less.

Qstn #4
:

#4-a [5]
The diagram below shows the Excretory System of a Human being. Study the same and then answer the questions that follow :

#4-a-i
Name the parts labelled 1, 2, 3 and 4.
Ans : 1-Posterior Vena Cava
2-Aorta
3-Renal Artery
4-Renal Vein

#4-a-ii
Give the main function of the parts labelled 5, 6, 7 and 8.
Ans : Part 5 : Ureter - Carry urine from kidneys to urinary bladder.
Part 6 : Urinary bladder - Contain the urine till it is released out.
Part 7: Sphincter muscles - Guards the urethra
Part 8: Urethra - Passage through which urine is given out of the body.

#4-a-iii
Name the endocrine gland which could be added in the diagram and state its location/position.
Ans : Adrenal gland. It is located above each kidney in the form of a cap.

#4-b [5]
Briefly explain the following :

#4-b-i
Osmosis
Ans : Osmosis : The process of movement of solvent molecules from a region of low concentration to a region of higher concentration through a semipermeable membrane.