GUIDED BY: M.NIRMALA.

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the m.p.u.hr.sec.school.

• GUIDED BY M.NIRMALA.
• DONE BYU.SABARISH.
• N.T.KISHORE KUMAR.
• B.SATISH KUMAR.
• V.PAVAN KUMAR.
• T.JAYA KUMAR.
  
  

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BRYOPHYTA
The Bryophyta can be considered to be the
precursors of the terrestrial plants.In this
chapter you are going to study the
example-polytrichum.
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EXTERNAL STRUCTURE(MORPHOLOGY)

• The structure of the plant body is divided into
  an with small leaves.The young leaves are
  spirally arranged in three rows at the tip of the
  stem.

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REPRODUCTION.

• Polytrichum undergoes vegetative and sexual
  reproduction.vegetative reproduction takes place
  by various ways by primary protonema as well as
  by the formation of gemmae.

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FERTILIZATION
The male gamete is chemotacally attracted by the
mucilaginous sap at the mouth of the archegonium.
The fertilized egg forms the diploid zygote.
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CONCEPTS.

• After fertlisation the diploid zygote produces
  the sporophyte.
• Polytrichum is dioecious.
• The male sex organ is called the antheridium and
  the female sex organ is called the archegonium.

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SPOROPHYTE AND CAPSULE

• The upper part elongates into a slender seta
  that
• bears the capsule at the tip. The central region
  of
• the capsule is formed of elongated cells called
  columella.

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Dispersal of the spore

• The peristome has 32 to 64 teeth . There is a
  ring of pores in between these teeth like
  structures. The spores are liberated out through
  these pores by the action of the wind.

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Development of the spore

• On falling onto a suitable substratum the
• Spores germinate into a new plant. Usually
• In the life cycle of polytrichum, the
  sporophyte is totally dependent on the
  gametophyte.