Lesson 1 - Plant Evolution and Adaptations

​Lesson 1 - Plant Evolution and Adaptations

Plant Evolution and Adaptations
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Plant Evolution

• Plants are multicellular

eukaryotes with tissues and
organs that have specialized
structures and functions.

• Primitive land plants evolved

~400 million years ago.

• Strong evidence that

multicellular land plants and
modern-day green algae
shared a common ancestor.

Multiple Choice

How long have plants been on land?

• 200 million years

• 4,000 years

• 400 million years

• 2,000 years

Plant Evolution and Adaptations
Copyright © McGraw-Hill Education

Plant Evolution

• Characteristics in common between plants and

green algae:

• Cell walls composed of cellulose
• Cell division that includes the formation of a cell

plate

• Same type of chlorophyll used in photosynthesis
• Similar genes for ribosomal RNA
• Food stored as starch
• Same types of enzymes in cellular vesicles

Multiple Select

Which of the following are characteristics in common between plants and green algae? (Choose all that apply)

• Cell walls composed of cellulose

• Cell division that includes the formation of a cell plate

• Food stored as protein

• Similar genes for ribosomal RNA

• Same type chlorophyll used in photosynthesis

Plant Evolution and Adaptations
Copyright © McGraw-Hill Education

Cuticle

• Living on land requires

different adaptations than
aquatic environments.

• Many plants have a fatty

coating on the outside of
cells called a cuticle.

• Lessens evaporation of

water from plant tissues

• Acts as a barrier to invading

microorganisms

Plant Adaptations to Land Environments

Multiple Choice

Which leaf structure reduces evaporation by keeping water inside the leaf?

• cuticle

• xylem

• stoma

• phloem

Stomata
• Plants need to exchange

gases for photosynthesis.

• Cuticles reduce water loss

but also prevent the
exchange of oxygen and
carbon dioxide.

• Stomata are openings in the

outer cell layer of leaves that
enable the exchange of
gases.

Plant Evolution and Adaptations
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Plant Adaptations to Land Environments

Multiple Choice

Gases pass in and out of a leaf through the

• phloem

• xylem

• cuticle

• stomata

Vascular tissue

• Some plants have specialized

transport tissue called
vascular tissue.

• Vascular tissue allows for

faster movement of
substances over greater
distances

• Plants with vascular tissue are

called vascular plants.

• Nonvascular plants move

substances with osmosis.

Plant Evolution and Adaptations
Copyright © McGraw-Hill Education

Multiple Select

How do nonvascular plants obtain water and nutrients? (Pick Two)

• They don't

• Absorbing them

• Osmosis

• Diffusion

Reproductive strategies

• Water is a limiting factor in the

environment of land plants.

• Some plants still produce

spores, which require water for
gametophyte growth.

• Seed plants have adaptations

that enable fertilization in the
absence of water.

Plant Evolution and Adaptations
Copyright © McGraw-Hill Education

Multiple Choice

The process in which a sperm cell and egg cell unite to form a zygote is called

• germination

• fertilization

• seeding

• photosynthesis

Seeds

• A seed is a plant structure

that contains an embryo,
nutrients for that embryo, and
a protective coat called the seed coat.

• Seeds allow plant embryos to

survive harsh conditions and
germinate during favorable
conditions.

Plant Evolution and Adaptations
Copyright © McGraw-Hill Education

Plant Adaptations to Land Environments

Multiple Choice

Part of the seed that protects the embryo and nutrients.

• Seed Coat

• Cotyledons

• Seed

• Shiny

Alternation of Generations

• In organisms with alternation of generations, haploid

gametophyte generations alternate with diploid sporophyte
generations.

• Depending on the type of plant, either the gametophyte or

sporophyte generation is dominant.

• The dominant generation is usually larger and accounts for

more time in the plant’s life cycle.

Plant Evolution and Adaptations
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Multiple Choice

The alternation of generations in plants goes between the diploid __________________ and haploid __________________

• sporophyte, gametophyte

• gametophyte, sporophyte

Multiple Select

What are the two stages of a plants lifecycle?

• gametophyte

• night

• day

• sporophyte

Plant Classification

• Plants developed a diversity of adaptations which are used

to classify them into divisions rather than phyla.

• Plant divisions fall into two groups: vascular and

nonvascular plants.

• Vascular plants can be further divided into plants that do or

do not produce seeds.

Plant Evolution and Adaptations
Copyright © McGraw-Hill Education

Plant Classification

Plant Evolution and Adaptations
Copyright © McGraw-Hill Education

Nonvascular

Vascular

Seedless

Seed – producing

Bryophytes (mosses)

Lycophytes (club
mosses)

Cycadophytes (cycads
or sago palms)

Anthocerophytes
(hornworts)

Pterophytes (ferns and
horsetails)

Gnetophytes (joint firs)

Hepaticophytes
(liverworts)

Ginkgophytes
(Ginkgoes)

Coniferophytes (pines)

Anthophytes (flowering
plants)