PLANTS: structure and function

March 2008

Mrs.. Snyder

Plants: Grouped by characteristics Vascular

Three main parts: roots, stems and leaves Roots can be different sizes:

Fibrous and tap roots Storage roots; beets, carrots, sweet potatoes and turnips

Roots have different functions: anchoring the plant, taking in water and minerals, and store food.

Nonvascular Simple; most grow in moist places No vascular tissues.

a protective covering that surrounds the seed

anchor the plant in place and absorb water and other minerals from the soil.

carries water and food to the rest of the plant.

makes the plant's food.

makes seeds.

Vascular Plants: Stems Function of stems

Support, transport of water & food Most stems grow upward Some stems grow sideward

Types of stems Green Woody

Transport of materials Xylem & phloem

Vascular Plants: Leaves Leaves come in variety of shapes and sizes Leaves are arranged in different ways

What do plants do?

All plants are alike in one way. They need three things in order

to surviveWatercarbon dioxideenergy from sunlight

What do you suppose the plants use these things for?

Classify – to sort into groups based on similarities and differences

They turn it into sugar!photosynthesis – a process by which plants change light energy from the sun and use it to make sugar

Plants and some protists conduct photosynthesis.

PhotosynthesisA movie of photosynthesis

chlorophyll – the green substance found in plants that traps energy from the sun and gives plants their green color

carbon dioxide – a gas found in air

As a plant makes sugar, oxygen is released

When the plant uses the sugar, water and carbon dioxide are released.

How Do Plants Get Energy

Plant leaves change light

energy into energy

the plant can use.

Stomata are tiny holes on the bottom of the leaf that let air (CO2.) in and (O2)out.

They get sunlight, water, and air (CO2.)

The veins of a leaf bring water and minerals to the leaf from the stems and roots.

Roots get water and minerals directly from the soil.

Because of this processScientists are able to classify living things

by the way they get their food. Plants are producers (autotrophs)

producer – it is a living thing that uses sunlight to make sugar. This sugar feeds others.

What Are the Parts of a Flower

Most flowers have four parts

Flower parts

Sepal – one of the leaf-like parts that protects a flower bud and that is usually green

Pistil – part of a flower that makes the eggs that grow into seeds

Stamen – part of a flower that makes pollen

Pollen – tiny grains that make seeds when combined with a flower’s egg

Plant Kingdom

Flowering Plants

Non-flowering Plants

2 groups

MossesMosses FernsFerns

Non - flowering Plants

Do NOT produce flowers

Examples of MossesExamples of Mosses

spores

Spore-producing capsule

No true roots, No vascular tissues (no transport)

Characteristics of MossesCharacteristics of Mosses

Simple stems & leaves

Have rhizoids for anchorage

Spores from capsules (wind-dispersal)

Damp terrestrial land

Simplest plants

underground stem

root

A leaf (finely divided into small parts)

roots, feathery leaves & underground stems

Characteristics of Ferns

have vascular tissuesvascular tissues (transport & support)

DampDamp & shadyshady places

Spore-producing organSpore-producing organ on the underside of leaves (reproduction)

FLOWERING FLOWERING PLANTSPLANTS

needle-shaped leaves

Male cones (in clusters)

Female cones (scattered)

roots, woody stems

Characteristics of GymnospermsCharacteristics of Gymnosperms

needle-shaped leaves

tall evergreen trees

cones with reproductive structures

dry places

vascular tissues (transport)

naked seeds in female cones

How Do Flowers Make Seeds and Fruits?

Great Plant Escape- Plant parts

Ovary – the bottom part of the pistil in which seeds form

Ovule - the inner part of an ovary that contains an egg

embryo – tiny part of a seed that can grow into a new plant

How Seeds Form After fertilization the flower

dries up and petals fall off, leaving just the pistil and its ovary.

The top of the pistil falls off and the ovary gets larger as one or more seeds form inside it.

When the seeds are formed, the ovary dries up and the seeds fall out.

Corn, Beans, and Peas are seeds that we eat

How Fertilization Occurs When a pollen grain reaches a pistil, it grows a

thin tube to the ovary. Sperm from the pollen grain combines with an egg, and a seed forms.

Fertilization – the combination of sperm from a pollen grain with an egg to form a seed

How Pollination Occurs

Butterflies may carry pollen from the stamen of one flower to the pistil of the the same flower. Sometimes the butterfly may carry pollen from the stamen of one flower to the pistil of another flower of the same kind.

Pollen: Nothing to Sneeze At

Pollination- the movement of pollen from a stamen to a pistil

Some flowering plants are

dicot seed – a seed that has two seed leaves that contain stored food

monocot seed – a seed that has one seed leaf and stored food outside the seed leaf

dicot seed – a seed that has two seed leaves that contain stored food

monocot seed – a seed that has one seed leaf and stored food outside the seed leaf

What is the Life Cycle of a Flowering Plant

Dormant Seed Takes in water and the

seed coat gets soft. If the seed has enough oxygen and the right temperature, it will begin to germinate.

dormant – the resting stage of a seed

Geminating Seed First a root pushes through the

seed coat and grows downward.

The top part of the root grows upward and becomes the stem. The stem carries the seed coat and the seed leaves with it. The seed coat falls off. The seed leaves provide food for the plant. Two small leaves begin to grow from between the seed leaves.

Seedling When the stored food within the original seed

leaves is used up, they dry up and drop off. More leaves grow from buds on the stem as the plant grows taller. The new leaves can trap energy from sunlight and make sugar. Plants use the energy in the sugar to grow.

How Do Other Living Things Get Energy? All living things need

energy to survive

Consumer – a living thing that gets energy by eating plants and other animals

Animals cannot use light energy to make sugar. Animals depend on plants for food.

Decomposer – a consumer that puts materials from dead plants and animals back into the soil, air, and water

Consider this…. What is one way to classify all plants into

two groups How do plants that do not make seeds

reproduce? In what part of a flower are seeds made? How are flowers pollinated? How is a monocot seed different from a

dicot seed?