Plant Evolution & Roots

By: Adi Beal and Madi McDade

Importance of Plants

Botany- the study of plants

Plants have a lot of diversity

Steps of Evolution

1st Step: Multicellular

2nd Step: Move onto Land

3rd Step: Vascular System

4th Step: Seeds

5th Step: Flowers & Fruits

1st Step: Multicellular

Aquatic organisms

Get support from water

Before multicellular

Volvox

Colony of individual cells that cooperate

First multicellular plant

Red Algae

Rhodophyta

Volvox Video

https://www.youtube.com/watch?v=He9FSeGRi3A

2nd Step: Move onto Land

Mosses had no adaptations for life away from water

First terrestrial plants

Bryophyta

Need ozone to block out UV rays which damage DNA

More cellulose for structure

Get water through roots

UV Damage Diagram

3rd Step: Vascular System

True roots and stems

Xylem

Phloem

Waxing coating on leaves to conserve water

Obtain CO2 through stomata, which close at night to prevent water loss

Stomata Diagram

4th Step: Seeds

Dispersed by wind, water, and animals

Spore-individual cells that clump and each contain embryo, an endosperm, and seed coat

Gymnosperms

Seeds are not covered by a true fruit

Gymnosperms Activity

http://studyjams.scholastic.com/studyjams/jams/science/plants/gymnosperms.htm

Seed Dispersal Diagram

Seed Video

https://www.youtube.com/watch?v=6loGKPKDqCw

5th Step: Fruits & Flowers

Fruit- plant structure which results from the pollination of a flower and contains a seed

Fruit may protect the seed

Angiosperms- flowering plant that produce seeds enclosed in a fruit

Flowers produce the reproductive part of the plant

Flowers attract pollinators like bees, bats, and butterflies

Angiosperm Activity

http://studyjams.scholastic.com/studyjams/jams/science/plants/angiosperms.htm

Plant Reproduction Diagram

Plant Evolution Video

https://www.youtube.com/watch?v=yL1o49YGhtM

Plant Adaptations

Waxy Cuticle

Stomata

Reproduction

Spores

Seeds

Vascular Tissues

Xylem

Phloem

Why Do Plants Adapt Activity

http://studyjams.scholastic.com/studyjams/jams/science/plants/plant-adaptations.htm

Monocot vs. Dicot Flowers

Monocot

Parts in threes or multiples of threes

Dicot

Parts in fours or fives or multiples of fours and fives

Monocot vs. Dicot Leaves

Monocot

Smooth often narrow shapes with parallel veins

Dicot

Oval or hand-like shapes with neck-like veins

Monocot vs. Dicot Vascular Tissue

Monocot

Vascular bundles scattered through stem

Dicot

Vascular bundles arranged in ring around stem

Monocot vs. Dicot Root Pattern

Monocot

Fibrous root system

Dicot

Taproot system

Monocot vs. Dicot Embryo in Seed

Monocot

Embryo has one cotyledon (seed leaf)

Dicot

Embryo has two cotyledons (seed leaves)

Monocot Examples

Lilies

Tulips

Bananas

Pineapples

Onions

Corn

Rice

Oats

Dicot Examples

Beans

Lettuce

Oak

Maple

Roses

Daises

Monocots vs. Dicot Video

https://www.youtube.com/watch?v=gI2RxzAT-ww

Monocot vs. Dicot Activity

http://www.math4childrenplus.com/monocots-and-dicots/

Tissue Types

1. Vascular tissue

1. Xylem- transports water to plant

2. Phloem- transports food and minerals

2. Apical Meristem- responsible for upward growth in plant and produces cells that will eventually specialize

Meristem

Types of Roots

1. Primary Root- the first root that appears out of a seed

2. Taproot- primary root grows thicker and longer with secondary roots growing off of it

3. Fibrous root- primary root branches off into many small roots

4. Lateral root- extend horizontally from primary root and anchor plant securely in the soil

5. Aerial root- root exposed to air and absorbs moisture

6. Adventitious root- a root that grows above ground or in an odd place

Root Types

Root Structure

1. Root Cap- hard protective layer, prevents breakage as plant pushed through soil, secretes slimy lubrication

2. Root hairs- increase surface area of root so more water and nutrients can be absorbed, main entry point of water

3. Epidermis- waterproof outermost layer, protection

4. Cortex- many layers of parenchyma cells, stores starch for energy

5. Endodermis- innermost cylinder of cortex, waterproof, regulates movement of water and minerals into vascular tissue

Root Structure (cont.)

6. Pericylce- outermost layer of cells of the steel, goes through cell division creating root hairs

7. Root system- constantly provides the stem and leaves with water and dissolved minerals

8. Root tip- where mitosis occurs

9. Permeable membrane-layer of the cell where water and nutrients can pass through

Root Structure Diagram

Root Growth

https://www.youtube.com/watch?v=eDA8rmUP5ZM

Root Activity

http://studyjams.scholastic.com/studyjams/jams/science/plants/roots-stems.htm

Fun Facts!! Roots are the parts of plain that grow down into soil or water, anchoring it

and soaking up all the water and minerals the plant needs to grow.

In some plants such as beetroots, the roots are also a food store.

When a seed begins to grow, its first root is called a primary root.

This branches into secondary roots.

Roots are protected at the end by a thimble shaped root cap as they probe through the soil.

How plants live On every root there are tiny hairs that help it to take up water and minerals.

Some plants, such as carrots, have a single large root, called a taproot, with just a few fine roots branching off.

Some plants, such as grass, have lots of small roots, called fibrous roots, branching off in all directions.

Some kinds of orchid that live on trees have ‘aerial’ roots that cling to the branches.

Mistletoe has roots that penetrate its host tree.

Roots are delicious when boiled or pickled. The roots of the South African wild fig tree can grow 120 m down into the ground.