Page 97 - Biology - XII

Q2. Plants develop defi ciency symptoms.
(a) It is not true, as plants extract elements as much as they want.

(b) It is true, as some elements are defi cient in soil.
(c) Both (a) and (b) (d) None of these
Q3. Fertilisers are source of

(a) elements (b) food (c) diseases (d) pollution

Q4. H, N, O, C, Ca, Mg, S, and Fe are
(a) elements needed by plants in large quantity
(b) essential for normal growth and development of plant
(c) called macroelements/macronutrients (d) all of these

Q5. Elements required by plants are absorbed as
(a) atoms (b) compounds (c) salts (d) ions

Answer key
1. (c), 2. (b), 3. (a), 4. (d), 5. (d)

PROJECT - 3
A. SEPARATION OF PLASTIDIAL PIGMENTS BY CAPILLARY ANALYSIS

Objective
To separate various plastidial plant pigments by capillary analysis.

Principle/Theory
1. There are diff erent types or categories of plastidial pigments. The pigments of chloroplast belong to
two chemical classes:
(a) Tetrapyrrolic compounds – such as green coloured chlorophylls.
(b) Hydrocarbon compounds – such as orange coloured carotene’s and yellow coloured xanthophylls.
2. The green colour of the plants may be masked by other pigments such as in red algae.
3. Cyclic tetrapyrrolic compounds are generally called porphyrins. They are widely distributed in nature.
Haeme of mammalian blood, coenzymes of biological oxidation (i.e. cytochromes, etc.) are also cyclic
tetrapyrrolic compounds.
4. Chlorophyll can be extracted by acetone from fresh green leaves and by acetone and alcohol both from
dry leaves. Chlorophylls are methyl/phytyl esters of dicarboxylic acid—chlorophyllins.

Materials Required
Filter paper strip, burette stand, string, petri dish, mortar, pestle, and fresh green leaves

Procedure
1. Take a raw chlorophyll solution in a petri dish.
(To prepare the chlorophyll solution, crush fresh spinach or other available (soft) leaves in mortar with
little sand + ether/alcohol.)

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