Identify the pair of heterosporous pteridophytes among the following:
Selaginella and Salvinia
Psilotum and Salvinia
Equisetum and Salvinia
Lycopodium and Selaginella
Heterospory involves the creation of spores in two distinct sizes and developmental trajectories: smaller ones known as microspores with a male role, and larger ones referred to as megaspores with a female role. This phenomenon, which is pivotal in the evolution of vascular plants, has ultimately paved the way for the emergence of seeds. Examples of plants showcasing heterospory include Selaginella, Salvinia, Azolla, and others.
Therefore, The correct option is (A): Selaginella and Salvinia
Column-I (Plant groups) | Column-II (Examples) | ||
1. | Bryophyta | p. | Pinus |
2. | Gymnosperm | q. | Adiantum |
3. | Algae | r. | Sphagnum |
4. | Pteridophyta | s. | Ectocarpus |
LIST I Classes of world vegetation on the basis of temperature | LIST II Example | ||
---|---|---|---|
A | Megatherms | I | Alpine vegetation |
B | Mesotherms | II | tropical rain forest |
C | Microtherms | III | Coniferous forest |
D | Hekistotherms | IV | Tropical deciduous forest |
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A : The potential (V) at any axial point, at 2 m distance(r) from the centre of the dipole of dipole moment vector
\(\vec{P}\) of magnitude, 4 × 10-6 C m, is ± 9 × 103 V.
(Take \(\frac{1}{4\pi\epsilon_0}=9\times10^9\) SI units)
Reason R : \(V=±\frac{2P}{4\pi \epsilon_0r^2}\), where r is the distance of any axial point, situated at 2 m from the centre of the dipole.
In the light of the above statements, choose the correct answer from the options given below :
The output (Y) of the given logic gate is similar to the output of an/a :
Pteridophytes are the first terrestrial vascular plants. Carolus Linnaeus classified them under the group cryptogamae. Pteridophytes occupy a transitional position between bryophytes and spermatophytes.
For Example, Silver fern, Equisetum, Selaginella