BIOLOGY | BOTANY
UNIT SIX : KINGDOM PLANTAE
CLASS : 11
Bryophyta
They include 960 genera and 24000 species. They grow in moist and shady places and some are aquatic. Plant body does not bear vascular tissues and not differentiated into root shoot and leaves. They show alternation of generation that is in the life cycle two forms of the plant body are produced.
Gametophytic generation
- The plant body in this generation produces gametes for sexual reproduction.
- The gametophytic generation is long lived.
- The plant body is green; autotrophic consists of root like structures on the ventral surface called rhizoids and scales
- The plant body bears male and female sex organs where male and female gametes are produced.
- The male sex organs are called antheridia and the female sex organs are called archegonia.
- Water is essential for fertilization.
- No embryo is developed from the development of zygote.
Sporophytic generation
- When male and female gametes fuse together zygote is formed which develops into sporophytic plant body.
- This generation is short lived.
- The sporophytic plant body is differentiated into foot seta and capsule.
- Within capsule of saprophyte spores are produced by meiosis division in spore mother cells. Eg. Marchantia, Funaria
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Biology