Question
Question: Which of the following divisions of the plant kingdom is characterized by a dominant sporophyte gene...
Which of the following divisions of the plant kingdom is characterized by a dominant sporophyte generation, but does not possess seeds?
(a)Bryophytes
(b)Angiosperms
(c)Pteridophytes (Tracheophytes)
(d)Conifers
(e)Monocots
Solution
The division of the plant kingdom that has a dominant sporophyte generation has its reproductive stage dependent on the sporophyte. The division is characterized by seedless vascular plants. They include horsetails and ferns.
Complete step by step answer:
The pteridophytes are one of the earliest divisions of plants to emerge on the planet. They include the horsetails and ferns. They are vascular plants that do not have seeds or flowers as they reproduce through unicellular haploid spores.
- Their life cycle alternates between a haploid sporophyte and a diploid gametophyte phase.
- The main plant body is a sporophyte differentiated into true root, stem, and leaves. The sporophytes bear sporangia subtended by sporophylls or leaf-like appendages.
So, the correct answer is ‘Pteridophytes (Tracheophytes)’.
Additional information: Bryophytes, like pteridophytes, are the simplest and one of the first plants to appear on the planet. They also have a gametophyte and a sporophyte stage, but the gametophyte is dominant. The sporophyte is dominant on the gametophyte.
- Angiosperms are vascular seed and flower-bearing plants. They also bear fruit. Monocots are a type of angiosperms distinguished by the presence of a single cotyledon in their seeds.
- Conifers are gymnosperms i.e. plants where the ovules are not enclosed in an ovary wall and remain exposed before and after fertilization. Conifers show needle-like leaves and other modifications that prevent water loss.
Note:
The first plants to colonize land appeared approximately 500 million years ago and were mostly related to bryophytes.
- Pteridophytes are the first plants to possess the vascular tissues - xylem and phloem.