adaptasi tanaman lahan nkering

Bahan Kajian MK. Agroekologi
Adaptasi Tumbuhan
pada
Lingkungan Habitat
Lahan Kering
Smno.jurstnh.fpub.2013
Apakah Tumbuhan itu?
• Multicellular organism that performs
photosynthesis and develops from an embryo
• Almost all live on land
• Descendants of protists
• Land invasion depended on evolution of
different structures
Copyright 2005—Brooks/Cole—Thomson Learning
Adaptasi Lahan-Darat
• Waxy cuticle — reduces water loss
• Ability to absorb water from a variety of
sources
• Enclosed reproductive organs, called
gametangia, in which gametes form
• Enclosed sporangia in which spores form
Identifikasi beragam Tipe Tumbuhan
• Identify as many different plants as you
can. How are they different from one
another?
Vaskuler vs. Non-vaskuler
• Vascular or
tracheophytes
• Have pipelike tissues
that conduct water
• Grow large
• Examples: fir trees,
ferns
• Nonvascular or
bryophytes
• Lack a vascular
system
• Much smaller
• Less diverse
Divisio Tumbuhan
Copyright 2005—Brooks/Cole—Thomson Learning
Evolusi Tumbuhan
Copyright 2005—Brooks/Cole—Thomson Learning
Evolusi Tumbuhan
1. Evidence comes from fossils and comparisons
with living species
2. First plants evolved from a common ancestor
that resembled a green alga
3. Vascular plants predate nonvascular plants
4. First seedless plants — Carboniferous Period
Kingdom Plantae
Copyright 2005—Brooks/Cole—Thomson Learning
Evolusi Angiospermae
• Angiosperms — flowering plants
• First fossils — about 125 million years ago
• Evolved from gymnosperms — plants that have
no fruits or flowers
• Many adaptations
Mosses, Liverworts and Hornworts
• Nonvascular Plants or
bryophytes
• Depend on free
standing water for
photosynthesis and
fertilization
Copyright 2005—Brooks/Cole—Thomson Learning
Karakteristik Bryophyta
• All parts of their bodies are adapted to absorb
water
• This gives them a spongy feel
• Exhibit alternation of generations — a sexual
life cycle in which haploid and diploid phases
are both multicellular
Siklus Hidup Lumut (Moss)
Copyright 2005—Brooks/Cole—Thomson Learning
Tumbuhan Berpembuluh (Vaskuler)
Copyright 2005—Brooks/Cole—Thomson Learning
Tumbuhan Berpembuluh (Vaskuler)
• Called tracheophytes
• Have division of labor with separate transport
systems for water (xylem) and sugars (phloem)
• Diploid Phase dominates the life of the plant
• Seeds are protected by coat, and food is stored
inside for germination
Seed-Lacking Tracheophytes
• 4 divisions that lack seeds:
– Pterophytes (ferns)
– Psilotophytes
– Lycophytes
– Equisetophytes
Siklus Hidup Paku-pakuan
Copyright 2005—Brooks/Cole—Thomson Learning
Siklus Hidup Paku-pakuan
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A fern releases haploid spores
Spores mature into haploid gametophytes
Gametophytes make sperm and egg
Fusion of sperm and egg
Zygotes grow right out of the gametophyte for
a new fern
Lycophytes
• Have true roots,
stems and simple
leaves
• Also called
lycopods
• Example: club
mosses
Copyright 2005—Brooks/Cole—Thomson Learning
Equisetophytes
• Referred to as
horsetails
• Have true roots,
stems and complex
leaves
• Stems are jointed
• Outer cell walls are
reinforced with
silica
Copyright 2005—Brooks/Cole—Thomson Learning
Reproduksi Tumbuhan Berbiji
• Manage fertilization without water
• Use a form of internal fertilization
• Sperm and ovum fused, and develop within
the female gametophyte
• Seeds consist of a diploid zygote and a source
of food encased in a seed coat
Gymnosperms
1. Seed plants without flowers
2. Evergreen
3. Conifers produce male and female
gametophytes in cone-shaped strobili (the
cones)
4. Male and female cones on same tree
Siklus Hidup Pinus
Copyright 2005—Brooks/Cole—Thomson Learning
Cycads
1. Large-leafed
plants that look
like palms
2. No flowers or
fruits
3. Bear naked
seeds
4. Produce male
and female
strobili
Copyright 2005—Brooks/Cole—Thomson Learning
Kegunaan Bunga dan Buah
• Flowers ensure distribution of pollen through
a variety of methods
• Fruits are mature ovaries that enclose and
protect seeds
• Fruits usually enhance dispersal of seeds
Siklus Hidup Tumbuhan Berbunga
Copyright 2005—Brooks/Cole—Thomson Learning
Reproduksi Angiospermae
• Flowers reproduce by means of double
fertilization
• 2 sperm nuclei from the pollen grain fertilize 2
ova from the ovary
• A diploid zygote is formed and a triploid cell
forms the endosperm
Bagian-bagian Bunga
• Stamen — anther and filament (male)
• Carpel — style and ovary (female)
• A corolla or petals and a calyx of sepals
surround stamens and carpels
• Not all flowers have all parts
Konsep-konsep Kunci
• A plant is a multicellular organism that
photosynthesizes and develops an embryo
• Nonvascular plants lack vascular tissues
• The vascular system enables plants to transport
water and nutrients, to grow large, and to
diversify
• Seeds allow plant to withstand dry environments