1. Plants

2. Overview of PLANTS Chapter 22

3. Overview of Plants
The plant kingdom’s impact on our lives cannot be overstated.
A broad understanding of plants as organisms – their anatomy, physiology, evolution, and diversity – is required for a complete understanding of biology.
Life on earth would not be possible without plants converting solar energy to chemical energy by photosynthesis.
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4. The Evolution of Plants
Before plants were able to live in terrestrial habitats, they needed ways to absorb minerals, conserve water, and reproduce on land. Vascular Tissue is the tissue that transfers water and other materials within the plant.
The nonvascular plants, commonly referred to as bryophytes, represent the earliest stages in plant evolution. They are referred to as nonvascular because they either have no vascular system or have only very simple vascular tissue.

5. Nonvascular Plants or Bryophytes
Do not have roots, stems or leaves
Water and food move through the body of nonvascular plants by osmosis and diffusion (because they do not have a system of tubes or vessels)
Characteristic = small, live in cool, wet environment
Example = Liverworts, Hornworts and Mosses

6. The Evolution of Plants continued
Many plants have vascular tissues that act as pipelines for carrying water from roots to leaves and for moving carbohydrates from leaves to roots.

7. Vascular Plants or Tracheophytes
Have roots, stems and leaves
Since they have conducting cells with reinforced walls, vascular plants are able to grow much larger than nonvascular plants.
Developed a waxy, watertight covering called a cuticle to aid during drought

8. The Cuticle Covers the above ground parts of the plant.
Prevents the tissues of the plant from drying out and losing water to the air.
It is impermeable to water.
It is impermeable to gasses required by plants for photosynthesis and cellular respiration.
Passages through the cuticle, specialized pores called stomata, enable gas exchange in the plant. Guard cells control the opening and closing of the stomata by expanding and contracting.

9. The Evolution of Plants continued
Plants exhibit a life cycle in which a haploid individual that produces gametes alternates with a diploid individual that produces spores. This is called Alternation of Generation.
Gametophyte
(n)
Gametes
Spores
Meiosis
Fertilization
Sporophyte
(2n)

10. The Evolution of Plants continued
Plants exhibit a life cycle in which a haploid individual that produces gametes alternates with a diploid individual that produces spores. This is called Alternation of Generation.
The first plants to invade land lacked roots, stems, and leaves. They took in water and other substances by osmosis and diffusion.
Nonvascular plants, such as mosses, liverworts, and hornworts, have vascular tissue that is very simple in design.
Modern vascular plants are distinguished by the following features: a dominant sporophyte, specialized conducting tissues, and a distinctive body form.

11. The Evolution of Seeds
The first vascular plants, such as ferns, were seedless and required a film of water for fertilization.

12. The Evolution of Seeds
The first seed-bearing plants were gymnosperms, which produced seeds that develop in cones.

13. The Evolution of Seeds
Angiosperms are flowering plants, which produce seeds that develop within fruits.

14. The Evolution of Seeds
A seed is a sporophyte plant embryo surrounded by a protective coat.

15. The Evolution of Flowers
Angiosperms are the most successful plants, comprising 90 % of all living plant species.
Flowers are reproductive structures that generally consist of four whorls of appendages.
In many angiosperms, flower structure is suited for a particular type of pollination.

16. The typical angiosperm undergoes double fertilization, a process in which two sperm fuse with cells in the megagametophyte to produce both a zygote and endosperm.
Angiosperms are classified as either monocots or dicots, depending on the number of cotyledons in their seeds.
Fruits are specialized for seed dispersal by agents such as animals, wind, and water.

17. General Plant Characteristics
Multicellular, eukaryotic, autotrophic (photosynthesis occurs in chlorophyll of chloroplasts) nonmotile (not mobile)
Common Name
Classifi-cation
Vascular Tissue
Structure
Life Cycle
Habitat
Simple or Complex Plant
Mosses, Liverworts
Phylum Bryotphyta
Absent
No true roots, stems or leaves
Gametophyte dominant sexual reproduction by fusion of sperm and egg
Moist areas
Simple
Ferns
Phylum Psilotophyta
Present
True roots, stems and leaves
Sporophyte dominant, distinct, multicellular gametophyte
Conifers
Phylum Coniferophyta
Sporophyte dominant, sexual reproduction in cones, seeds- Gymnosperms
Wide spread
Complex
Flowering plants
Phylum Anthophyta
Sporophyte dominant, sexual reproduction in flowers, seeds- Angiosperms

18. Kingdom Plantae
Seedless
Seeds
Gymnosperms
Angiosperms
ferns
mosses
club mosses
dicots
horsetails
ginkgo
cycads
monocots
whisk ferns
conifers
gnetophytes

19. Don’t forget to study for your Chapter __ “Overview of Plants”
Quiz #1
When? THE FIRST OF
NEXT CLASS