Plant Diversity

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Slide 1

Plant Diversity

Adapted from Prentice Hall

Slide 2

What are Plants?

Plants are multicellular eukaryotes that have cell walls made of cellulose.

Plants develop from multicellular embryos and carry out photosynthesis using the green pigments chlorophyll a and b

Slide 3

Plant Life Cycle

Plants go through Alternation of Generations

Slide 4

The Plant Life Cycle

During the two phases of the life cycle, mitosis and meiosis alternate to produce the two types of reproductive cells — gametes and spores.

The diploid (2N) phase is called the sporophyte, or spore-producing plant.

The haploid (N) phase is called the gametophyte, or gamete-producing plant.

Slide 5

What Plants Need to Survive

In order to survive, plants need:

sunlight

water and minerals

gas exchange (need CO2 & give off O2)

transport of water and nutrients throughout the plant body

Slide 6

Early Plants

The first plants evolved from an organism similar to the multicellular green algae living today.

Slide 7

Early Plants

The oldest known plant fossils, about 450 million years old, are similar to today’s mosses.

They had a simple structure and grew close to the ground.

Slide 8

Overview of the Plant Kingdom

Plants are divided into four groups based on these features:

water-conducting tissues

seeds

flowers

Plants are also classified by other features, including reproductive structures and body plan.

Slide 9

Evolution of the Plant Kingdom

Flowering plants

Cone-bearing plants

Ferns and their relatives

Mosses and their relatives

Flowers; Seeds enclosed in fruit

Water-conducting (vascular) tissue

Seeds

Green algae ancestor

Slide 10

Bryophytes

Moss & Fern

Slide 11

Groups of Bryophytes

Mosses and their relatives are called bryophytes, or nonvascular plants.

They do not have vascular tissues, or specialized tissues that conduct water and nutrients.