Question

Refer to the given dichotomous key and select the correct option regarding it.
I. (a) It is a seedless plant - Go to II
(b) It is a plant having seeds - Go to IIII
II. (a) True stem, leaves and roots are absent - $P$
(b) True stem, leaves and roots are present - $Q$
III. (a) Fruit is not formed and seeds are naked - $R$
(b) Fruits are formed and seeds are protected - $S$

• A. P - Pteridium, Q - Ephedra, R - Lycopodium, S- Acer
• B. P - Selaginella, Q - Funaria, R - Cycas, S - Fern
• C. P - Marchantia, Q - Pteridium, R - Oryza, S - Thuja
• D. P - Riccia, Q - Azolla, R - Pinus, S - Brassica

Answer 1

The correct option is D P - Riccia, Q - Azolla, R - Pinus, S - Brassica

Plants are classified into pteridophytes, bryophytes, gymnosperms and angiosperms. Pteridophytes and bryophytes are seedless plants. True stem, leaves and roots are absent in bryophytes. Examples include Marchantia, Riccia, Funaria. True stem, leaves and roots are present in pteridophytes. Examples include Pteridium, Selaginella, Lycopodium, Azolla. Angiosperms and gymnosperms are seed-bearing plants. Seeds in gymnosperms are naked and fruits are not formed. Examples of gymnosperms include Ephedra, Cycas, Pinus, Thuja. Angiosperms are fruit-bearing plants. The seeds are protected in them. Examples include Acer, Oryza, Brassica.

Hence, the correct answer is 'P - Riccia, Q - Azolla, R - Pinus, S - Brassica.'