Question

Identify the pair of heterosporous pteridophytes among the following:

• A. Selaginella and Salvinia
• B. Psilotum and Salvinia
• C. Equisetum and Salvinia
• D. Lycopodium and Selaginella

Answer 1

The Correct Option is A

The question requires identifying the pair of heterosporous pteridophytes. Let's first define what heterosporous pteridophytes are. Heterosporous plants produce two distinct types of spores: microspores (male) and megaspores (female). This differentiation helps in the sexual reproduction process.

Now, let's analyze the options:

1. Selaginella and Salvinia

   Both of these plants are well-known heterosporous pteridophytes. Selaginella belongs to the group known for having ligules and producing two types of spores, while Salvinia, an aquatic fern, also produces distinct spores. Therefore, this option is correct.

2. Psilotum and Salvinia

   Psilotum is a homosporous plant, meaning it does not produce two distinct types of spores, which makes this pair incorrect.

3. Equisetum and Salvinia

   Equisetum, commonly known as horsetail, is a homosporous species. Hence, it cannot pair with Salvinia for this category.

4. Lycopodium and Selaginella

   Lycopodium is another example of a homosporous genus, therefore making this pair incorrect.

Conclusively, the correct answer is: Selaginella and Salvinia.

Answer 2

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