Question

In Bryophytes, what is absent?
(A) Embryo formation
(B) Fertilization
(C) Motile gametes
(D) True roots and vascular tissue.

Answer 1

Hint: Bryophytes are the simplest and the primitive plants that are terrestrial in nature. These plants are classified into three types as liverworts, hornworts and the mosses. They are small plants and they can sustain even in very dry conditions.

Complete answer:
Bryophyta incorporates the plants of very simple and primitive origin. It has the free gametophyte and parasitic sporophyte in its life cycle. They are non-vascular land plants with undifferentiated plant bodies. This plant body does not divide into genuine leaves, stem and roots. Bryophytes produce encased conceptive structures called gametangia and sporangia however they don't create blossoms or seeds. In all bryophytes, the photosynthetic period of the existence cycle is only haploid instead of the diploid sporophyte.

In each cycle, a haploid gametophyte, every one of whose cells contains a fixed number of unpaired chromosomes, substitutes with a diploid sporophyte, whose cell contains two arrangements of matched chromosomes. bryophyte sporophytes are very small structures and are connected to their gametophytes for its nutrition and health. It comprises a single unbranched tail, or seta, and a stalk called the terminal sporangium. Hence the bryophytes lack the true roots and the vascular tissue.

Hence the correct answer is OPTION(D)

Note: Like all land plants, bryophytes have life cycles that alter in the generations like gametophyte and the sporophyte. Gametophytes produce haploid sperm and eggs which wire to shape diploid zygotes that develop into sporophytes. The spores produced by the sporophytes by meiosis get developed into gametophytes.