1. Plant Diversity F. Y. B. Sc. Prof. Ms. Vrushali S
Plant Diversity F. Y. B. Sc. Prof. Ms. Vrushali S. Dighe Department Of Botany S. M. Joshi College, Hadapsar, Pune.

2. What is a Plant? Plants are the base for the food chain on land.
Provide shade, shelter and oxygen
Evolved more than 470 million years ago
Multicellular, Eukaryotes
Cell walls made of cellulose
Photosynthesis using chlorophyll a and b
Most are autotrophs; few parasites + saprobes
Ex. Trees, shrubs, grasses, mosses and ferns

3. Life Cycle Haploid (N)-Gametophyte; gamete-producing
Diploid (2N)-Sporophyte; spore-producing
Produce a new individual by mitosis
All plants have both phases, but in different forms
Can reproduce independently of water
Some also reproduce asexually (vegetative)

4. Generalized Plant Life Cycle
Section 22-1
Haploid
Diploid
MEIOSIS
Spores (N)
Sperm (N)
Eggs (N)
FERTILIZATION
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5. Plant Survival Sunlight Water and Minerals Movement of Water/Nutrients
Taken up through the roots
Movement of Water/Nutrients
Make food in their leaves
Water and nutrients carried upward through tissue from soil
Gas Exchange

6. Early Plants Evolved from multicellular green algae
First plants were dependent on water
Similar to today’s mosses in structure and growth close to the ground
Evolved different adaptations for terrestrial environments

7. Cladogram of Plant Groups
Section 22-1
Cone-bearing plants
Ferns and their relatives
Seeds
Water-Conducting (Vascular) Tissue
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8. Overview of the Plant Kingdom
Divided into four groups based on water- conducting tissues, seeds and flowers
Reproductive structures and body plan are also considered
Compare DNA sequences of various species
Deep Green (1994)-Evidence that first plants evolved from green algae that lived in fresh water

9. The Diversity of Plants
Section 22-1
Cone-bearing plants 760 species
Flowering plants 235,000 species
Ferns and their relatives 11,000 species
Mosses and their relatives 15,600 species
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10. Bryophytes Nonvascular plants 1) Mosses (in swamps)
Can live in harsh environments
Rhizoid-long, thin cells absorb water and minerals and anchor them to the ground
2) Liverworts and 3) hornworts
Use osmosis to draw up water
Water needed for reproduction
Act as natural sponge and form peat moss

11. Bryophytes Mosses Liverworts Hornworts

12. Seedless Vascular Plants
Vascular tissue-Specialized to conduct water and nutrients thought he body of the plant
Xylem-form of vascular tissue that carries water upward from the roots to every part of the plant
Phloem-transports solutions of nutrients and carbohydrates from photosynthesis
Tree rings in the lower trunk indicate the tree age
Formed by cell division in thin layers inside bark
Width of the bands indicate environmental conditions for each year (Ex. Drought conditions)

14. Ferns Evolved 350 million years ago
Roots-Underground organs to absorb water and minerals with water-conducting tissue
Leaves-Photosynthetic organ that contain bundles of vascular tissue
Veins-Made of xylem and phloem
Stems-Connect roots and leaves

16. Seed Plants Gymnosperms-Seeds on cone surfaces
Conifers, Cycads, Ginkgoes and gnetophytes
Angiosperms-Flowering plants with seeds in tissue layers
Flowers or cones transfer sperm by pollination and protect embryos in seeds
Life cycle alternates between gametophytes and sporophyte

17. The Structure of a Seed Seed coat Seed Embryo B Stored food supply A
Section 22-4
Seed coat
Embryo
Stored food supply
Seed B A
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18. Reproduction without Water
Cones-sporophyte structures which are seeding bearing for gymnosperms
Flowers-Seed-bearing structure of angiosperms
Pollen Grains-Contain male gametophytes
Seeds-Embryo of seed plant with seed coat and food supply
Eaten and dispersed by animals or stick to their fur
Fossils from 30 million years ago

19. A Bee With Pollen On It’s Leg

20. Gymnosperms Cone Bearers / “naked seed” Gnetophytes:
a) Ex. Welwitschia-Namibian desert with large, leathery leaves; spread across the ground
Cycads- (Cycadophyta):
a) Palm-link plants with large cones
b) Appeared during Triassic Period (225 million years ago)
c) Grow in tropical and subtropical places

21. Welwitschia mirabilis, a Gnetophyte
Welwitschia mirabilis, a Gnetophyte. And Zamia pseudoparasitica, a Cycad.

22. Gymnosperms Ginkgoes-Only Ginkgo biloba currently exists
One of the oldest seed plant species alive today
Cultivated in China and planted around temples
Often planted in urban settings in U.S. due to resistance to air pollution
Conifers-(Coniferophyta)
Ex. Pines, spruces, firs, cedars, sequoias, redwoods
Long, thin leaves (Ex. Pine needles)-reduces surface area, waxy layer
Most are “evergreens” with cycling of needles

23. Ginkgo and Pseudotsuga menziesii, a Conifer.

24. Angiosperms Phylum Anthophyta “enclosed seed”
Cretaceous Period (135 million years ago) arrival
Dominate Earth’s plant life
Reproduce with flowers or fruits
Ovary develops into fruits to protect seed and for dispersal
Fruit-thick wall of tissue surrounding the seed

25. Seed Dispersal By Wind And General Flower Structure

26. Monocots and Dicots Cotyledons-Seed leaves in the plant embryo
Monocots-One seed leaf, parallel veins, multiples of 3 floral parts, vascular bundles scattered and fibrous roots
Dicots-Two seed leaves, branched veins, multiples of 4 or 5 floral parts, vascular bundles in a ring and a taproot

27. Comparison of Monocots and Dicots
Section 22-5
Monocots
Dicots
Single cotyledon
Parallel veins
Floral parts often in multiples of 3
Vascular bundles scattered throughout stem
Fibrous roots
Two cotyledons
Branched veins
Floral parts often in multiples of 4 or 5
Vascular bundles arranged in a ring
Taproot
Seeds
Leaves
Flowers
Stems
Roots
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28. Monocots and Dicots http://www. emc. maricopa

29. Diversity of Angiosperms
Wood plants made of cells with thick cell walls (Trees, shrubs and vines)
(Ex. Grapes and Ivy vines)
(Ex. Blueberries and rose bushes)
Herbaceous plants-No wood production as they grow (Ex. Dandelions, zinnias, sunflowers and petunias)

30. Rose Bush, Grape Vine, Zinnias and Petunias http://www. flowers

31. Diversity of Angiosperms
Annuals-Complete a life-cycle within one growing season
(Ex. Marigolds, petunias, pansies, zinnias, wheat and cucumbers)
Biennials-Complete their life cycle in 2 years
Year 1-germinate and grow roots & very short stems
Year 2-Grow new stems and leaves and produce flowers and seeds
(Ex. Primrose, parsley, celery)
Perennials-Live for more than 2 years
(Ex. Asparagus, grasses-herbaceous stems)
(Ex. Maple trees-wood stem)

32. Primrose, Marigolds, Ornamental Grasses