adaptasi tumbuhan pada lingkungan habitat lahan kering bahan kajian mk. agroekologi...
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Adaptasi Tumbuhan pada
Lingkungan Habitat Lahan Kering
Bahan Kajian MK. Agroekologi
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
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 plants4. First seedless plants — Carboniferous Period
Evolusi Tumbuhan
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
• 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
Tumbuhan Berpembuluh (Vaskuler)
Seed-Lacking Tracheophytes
• 4 divisions that lack seeds:– Pterophytes (ferns)– Psilotophytes– Lycophytes– Equisetophytes
Siklus Hidup Paku-pakuan
Copyright 2005—Brooks/Cole—Thomson Learning
• 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
Siklus Hidup Paku-pakuan
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 flowers2. Evergreen3. 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