Transcript 8. Kingdom Plantae.pptx

Kingdom: Plants
Biology 11: Section 3.2
Learning Goals
• Students will know the phylogeny of plants
• Students will know plant characteristics
• Students will understand the major groups of plants
Importance of Plants
• Plants are at the foundation of most non-extreme
ecosystems.
• Plants are at the start of most food chains, converting
solar energy to chemical energy, cycling carbon in CO2
into sugars, and removing toxins from soil.
• We use plants for food, shelter, fuel, fibre, and medicines.
Common Characteristics of Plants
• All plants have the following things in common:
1) Plants are eukaryotic.
2) Plants are multicellular with the exception of the green algae
inclusion to the plant kingdom.
3) Plants have cell walls made of the carbohydrate cellulose.
4) Plants use the pigment chlorophyll, found in organelles called
chloroplasts, for photosynthesis; autotrophic
Common Characteristics of Plants: Cont’d
5) Most plants are terrestrial.
6) Most plants have a life cycle that alternates between haploid and
diploid. A plant’s life cycle is called an alternation of generations if it
cycles from one type of generation to the other.
7) The haploid generation, the gametophyte, produces gametes
(-phyte is Greek for “plant”).
8) The diploid generation, the sporophyte, produces spores.
9) In humans, the haploid stage is the sex cells, whereas normal body
cells are diploid.
The Evolution of Plants
• Ancestors of modern plants were aquatic organisms similar to green
algae.
The Evolution of Plants: Cont’d
• To become land-based, plants developed several
adaptations:
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formation of an embryo that grows into a plant
adaptations to absorb sunlight by growing tall or wide
tissues to transport nutrients, water, and wastes
adaptations to reduce water loss
strategies to disperse reproductive structures
The Four (4)Major Groups of Plants
1. Bryophytes: Mosses
- Nonvascular and no true leaves
- Seedless and lack roots
- Protective cuticle and stomata for gas
exchange
- Moist environments since they rely on
osmosis, diffusion and active transport
for nutrients
- Mosses, liverworts, hornworts
2) Lycophytes and Pterophytes: The Ferns
- Seedless vascular plants
- Vascular tissues (xylem and phloem) transports water and nutrients
- Lycophytes – club mosses
- Pterophytes – ferns and their relatives
Gynosperms and Angiosperms: Seed Plants
• Seed is protective coating for the developing embryo
• Large variety of textures, sizes, shapes, odours, and colours
• Reproductive structres are not dependent on water
• Most widely distributed and complex group of plants on Earth (over
270 000 species known)
3) Gynosperms: The conifers
- Produce naked seeds in cone-like structure
- Pines, spruces, junipers, cedars, etc.
- Thin, needle-like leaves covered in waxy cuticle to reduce water loss
- Roots extend over a wide area rather than penetrating deep into the
soil
- Have male and female cones
4) Angiosperms: The Flowering Plants
- Most successful plant group
- All reproduce by alteration of generations, but some can reproduce
asexually
- After fertilization, seeds develop within the ovary and are enclosed in
fruit (fruit is there to help disperse seeds)
Flowering Plants
• All flowering plants are angiosperms
• Flower is the reproductive centre of
the plant
• “perfect flowers” contain both male
and female parts
https://www.youtube.com/watch?v=6honxJ2uzwo
To Do:
• Complete the review questions on page 95