Plant DiversityThe Evolution and Classification of

Plants

True or False1. All plants perform photosynthesis.

2. All plants need water and nutrients.

3. All plants reproduce using flowers.

4. All plants reproduce using seeds.

Warm-up: Answer for EachSlide # 2

PLANT CHARACTERISTICS1. Multicellular eukaryotes2. Photosynthetic autotrophs containing

chloroplasts.3. Non-motile (fixed to one spot)4. Cell walls made of cellulose5. Respond to environment and grow by

using hormones

Slide # 3

What Plants Need to Survive

1.Sunlight2.Gas exchange - System for

taking in CO2 and releasing O2

3.Water 4.Minerals

All are needed so that plants can carry out photosynthesis!

Slide # 4

Green algae

Moss

Vascular tissue

Seeds

Flowers

Ferns

GymnospermsAngiosperms

Cladogram of Kingdom PlantaeSlide # 5

The ancestors of plants were multicellular green algae. They were completely immersed in water & dissolved minerals.

To move onto land, plants had to solve these problems:

1. How to get chemical resources (water, minerals, oxygen, and carbon dioxide) separated into air and soil

2. How to transport resources within the plant.

3. How to keep from drying out

4. How to reproduce without water

Problems with Living on LandSlide # 6

SOLUTIONS (ADAPTATIONS)1. Leaves (CO2) and roots (H2O)

2. Develop a vascular system to transport resources in plant

3. Have a protective layer – cuticle (waxy outer layer) to keep from drying out

4. Specialized structures for reproduction including spores & seeds that do not dry out

Slide # 7

Vascular Tissue

1. Vascular Tissue- hollow

tube-like cells that transports

materials throughout the plant Xylem- transports H20 up from roots. Phloem- transports food made in photosynthesis to where it is needed in the plant.

Slide # 8

Xylem (water)

Phloem (food)

Bryophytes - NONVASCULAR

1. Live in moist, shady areas

2. NO vascular (transport) system

3. Small size because no vascular tissue

4. No true roots, stems, or leaves

5. Need water for reproduction.

6. Reproduces using spores, -asexual cell that can grow into a new organism.

7. Examples: Moss, Liverworts, & Hornworts

Slide # 9

moss

liverworts

hornworts

1. Have vascular tissue.2. Have true roots,

stems & leaves3. They grow in moist,

shady habitats.4. Have underground

stems, roots, & large leaves called fronds.

5. Reproduce using spores, NOT seeds.

Ferns - Seedless Vascular Plants

There are

11,000 species of ferns.

Sori

Slide # 10

ADVANTAGE: reproduction IS NOT dependent on water:

1. Seed contains a. A fully developed embryob. Food supply for embryoc. A water-proof seed coat to keep

from drying out2. Sperm transferred in water-proof

pollen through pollination by wind or animals.

3. Developed seed-bearing structures: Cones & Flowers

Seed PlantsSlide # 11

embryoendosperm

Seed coat

1. Cycad (Sago palm), 2. Ginkgo, 3. Conifer (pine, spruce, firs, cedars, sequoias,

redwoods, junipers, yews, & cypress trees)

Gymnosperms- “naked seed”

Sago Palm Ginkgo Ginkgo

Slide # 12

1. Most common gymnosperms are Conifers

2. Conifers have leaves called needles or scales have a reduced surface area and thick waxy coat on the needle to reduce water loss and prevents freezing.

Gymnosperms-ConifersSequoia

JuniperPine

Slide # 13

Conifer Reproduction

1. Male cones produce pollen and the female cone produces eggs and seeds.

2. Pollen is inefficiently transferred by the wind.

3. Once mature, the scales on the female cone dry out and open scattering the seeds by the wind.

Pollen

Pollen Cone

Seed Cone

Slide # 14Slide # 14

Angiosperms- “enclosed seeds”1. Flowering plants that

encourage direct and efficient pollen transfer (smell, color and offering nectar)

2. Pollinators are flying insects, birds, and bats that transfer pollen from flower to flower.

3. Flowers contain ovaries, which is where eggs/seeds are produced.

4. A fruit is the pollinated ovary containing mature seeds.

Slide # 15

Two Divisions of Angiosperms: Monocots and Dicots

Slide # 16