ISC Board Important Questions

Biology

[Set-1]

Q1. a) (i). Absorption spectrum and Action spectrum

Answer: A curve obtained by plotting the amount of absorption of different wavelengths of light by a particular pigment is called absorption spectrum of that pigment. An action spectrum is a curve showing the effectiveness of different wavelengths of light in stimulating the process being investigated.

(ii). Heart Wood and Sap Wood

Answer: In most trees the outer light colored region of the wood is distinct from the inner dark colored region. The former is said to be Sapwood (alburnum) and the latter Heartwood (duramen). The Sapwood consists of living cells which are still functional whereas the heartwood is composed of dead cells which become impregnated with resins, gummy or tannin like substances and consequently are not suited for conduction.

b) (i). What makes the apical meristem of the root sub-terminal?

Answer: A single tetrahedral apical cell is the structural and functional unit of the root apical meristem. The division in this apical cell in the upper plant. Three sides give rise to tissues to the body of the root, and the root cap is derived from its base.

(ii). Name the enzyme which catalyses bicarbonate formation in RBCs.

Answer: Carbonic anhydrase.

(iii). Which form of phytochrome induces flowering in SDP?

Answer: Far-red light

c). Fill in the blanks :

(i) The pigment in red muscle fibre is ………

(ii) Amount of blood pumped by heart per minute is called ………

(iii) Ethylene accelerates ……… of leaves, flowers and fruits.

(iv) The biological name of Tulsi plant is ………

(v) ……… is the causative agent of Cholera.

Answer: (i) Myoglobin. (ii) Cardiac output.   (iii) Growth.   (iv) Ocimum sanctum.    (v) Vibria cholerae.

d). Give the contributions of the following scientists:

(i) William Roentgen

(ii) Marshall Hall

(iii) Godfrey Houns field

(iv) Munch

(v) Robert Koch

Answer: (i) Discovery of X-rays.

(ii) Circulatory physiology - The father of modern neurology.

(iii) First invented CT scan and awarded Nobal Prize for this work in 1979.

(iv) Proposed Mass or pressure Flow hypothesis to explain the mechanism of phloem translocation.

(v) Proposed Koch's postulates.

e). Elaborate the following :

(i) MRI     (ii) IUD     (iii) SAN     (iv) CNS     (v) IPM

Answer: (i) MRI - Magnetic resonance imaging.

(ii) IUD - Intra Uterine devices.

(iii) SAN - Senatorial node

(iv) CNS – Central Nervous System

(v) IPM - Integrated Pest Management

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