Question

Which of the following gametophytes is not independent free living?

• A. Pteris
• B. Marchantia
• C. Pinus
• D. Funaria

Answer 1

The correct option is C

Pinus

The correct option is C.

Explanation of the correct option:

1. One of the two alternate multicellular phases in the life cycles of plants and algae is the gametophyte.
2. The gametophyte stage of the life cycle of plants and algae is called the gametophyte.
3. It develops from a single-chromosome haploid spore into a multicellular haploid organism.
4. Gymnosperm is Greek for "naked seed."
5. Typically, gymnosperms have needles that remain green all year long.
6. Pines, cedars, spruces, and firs are a few examples.
7. In Pinus, there are two prothallial cells and one antheridial cell in the microspore or pollen grain.
8. The male gametophyte's vegetative tissue is represented by the prothallial cells, and the antheridial cell splits into a small generative cell and a large tube cell.

Explanation of the incorrect options:

Option A:

1. Pteris is a genus of coarse ferns in the Polypodiaceae family with variously divided or, in some cases, simple fronds, a marginal linear continuous sorus, and an indusium made of the frond's reflexed margin.
2. Because every spore is identical in terms of structure and function, Pteris is a homosporous pteridophyte.
3. Spores have two walls surrounding a triangular, trilete-shaped opening.
4. Male and female gametophytes can live on their own and are independent.

Option B:

1. Funaria is a member of the Bryopsida class.
2. Funaria hygrometrica is commonly referred to as "cord moss" because of its twisted seta, which is very hygroscopic and untwists when moist.
3. Funaria is a member of the moss family of plants.
4. The most prevalent species among them is called cord moss and is called Funaria hygrometrica.
5. The male and female gametophytes of gymnosperms have autonomous, free-living existences, in contrast to bryophytes and pteridophytes.

Option D:

1. The genus Marchantia belongs to the order Marchantiales and the family Marchantiaceae of liverworts.
2. It is a bryophyte, Marchantia.
3. These are straightforward plants without vascular or root systems.
4. Marchantia's thallus differentiates into two layers: a top photosynthetic layer with a distinct upper epidermis and pores; and a bottom storage layer.
5. Unlike bryophytes and pteridophytes, the male and female gametophytes of gymnosperms have autonomous, free lives.

Final answer: Pinus gametophyte is not independent free living.