Page 150 - Biology_F5

Comparative studies of natural groups of organisms

Adaptations of Funaria to its mode of
life Exercise 3.11

Members of Funaria have the following 1. Briefly explain how bryophytes
adaptive features: have managed to overcome
various challenges in terrestrial
(a) They have chlorophyllous “leaf-like habitats.
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structures” for photosynthesis.
2. Explain why bryophytes are
(b) They have limited heights to overcome regarded as amphibious plants.
problems associated with lack of
vascular tissues. Water and mineral 3. Outline the distinctive features of
salts can move up by capillarity in division Bryophyta.
their short stems.

(c) They possess rhizoids for anchorage 3.6.2 Division Filicinophyta
on soil as well as absorption of water (Pteridophyta)
and mineral salts. Members of division Filicinophyta
(d) Male gametes, antherozoids, are are called pteridophytes. Examples of
biflagellate for swimming into pteridophytes include ferns. Pteridophytes
archegonia. inhabit damp shady environments, such
as on the floor of moist forests and river
(e) They produce small and light spores banks. Currently about 1100 species of
that are easily dispersed to allow ferns have been identified. Ferns are related
colonisation of new areas.
to bryophytes in several ways, implying
(f) The spores are tolerant to long periods that they might have probably descended
of unfavorable conditions due to the from bryophytes. For example, sexual
presence of a thick resistant outer wall reproduction in pteridophytes depends on
with sporopollenin, one of the major water, as in bryophytes. Moreover, like
chemical components (polymers) on bryophytes, the pteridophytes’ zygotes
the outer wall of the spores. are retained and they develop inside the

(g) They have elongated seta to expose multicellular archegonium. However,
the capsule to air for easy dispersal of unlike bryophytes, pteridophytes exhibit
spores. alternation of generation in which the
sporophyte generation is dominant over
(h) Archegonia secrete chemical gametophyte generation, which is relatively
attractants, which attract antherozoids reduced and dependent on sporophyte. Ferns
to swim towards the egg during are also heterogenous in size and shape,
fertilisation. ranging from filiform ferns to tree like ferns,
which can grow to approximately 20 metres
tall and with broad leaves known as fronds.
A fern tree called Cyathea manniana is very
common in most parts of the Eastern Arc

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