Plants

Plants in the Food we Eat

Is it a root? Is it a stem? Is it a leaf? Is it a flower? Is it a fruit? Is it a vegetable?

Plants are classified by their characteristics or features: roots, stem, leaf, fruit and vegetable

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.

Roots Roots are classified either as taproot

system or fibrous root system. Taproot system: A root with a few

branches that is very thick and swollen. Carrots are an example.

Fibrous root system: Some plants have a root system like this. It is a bunch of very fine roots. Grass plants have a fibrous root system.

Stems Xylem cells moves water from the

roots to the leaves. The phloem cells move the food.

Where the leaves join the stem is called the node. The space between the leaves and the stem is called the internode.

Stems (cont.)Supports the other parts of the plants that

are above ground. Holds up plant parts toward the sun so the plant can receive the light energy that it needs

Stems protect the important stuff on the inside. Protects the vascular system of the plant from environmental (weather), mechanical, insect or animal damage. 

Stems serve as transport systems in plantsSmall tubes from the roots go up

through their stemsWater and minerals are carried from the

roots to the leaves of the plant

Leaves Simple leaves are made of a single

leaf blade connected by a petiole to the stem. An oak leaf or a maple leaf are examples.

A compound leaf is a leaf made up of separate leaflets attached by a petiole to the stem like an ash or a locust.

Leaves (cont.) Cuticle is the waxy coating on the

outer surface of a leaf, which offers protection. Veins carry water and nutrients within the leaf.

Fruit The fruit is the ripened ovary of a plant

containing the seeds. After fertilization, the ovary swells and becomes either fleshy or hard and dry to protect the developing seeds.

Many fruits help seeds spread (maple seeds).

Many things we call vegetables are really fruits such as tomatoes, cucumbers, and beans.

Flower Flowers are important in making seeds.

The female part is the pistil. The pistil usually is located in the center of the flower and is made up of three parts: the stigma, style, and ovary. The stigma is the sticky knob at the top of the pistil. It is attached to the long, tube-like structure called the style. The style leads to the ovary that contains the female egg cells called ovules.

Flowers(cont.) The male parts are called stamens

and usually surround the pistil. The stamen is made up of two parts: the anther and filament. The anther produces pollen (male reproductive cells). The filament holds the anther up.

Structure of a Flowering Plant

Flower(cont.) The male gamete is made in the

filament and is found inside the pollen grain.

The female gamete is found in the ovary and is called an ovule.

Petals attracts insects for pollination. Nectary secrete a sugary fluid or

nectar which serves as a food source for pollinating insects.

Flower(cont.) Sepals encloses and protect bud. Carpel is the female reproductive

organ of a flower, consisting of an ovary, a stigma, and usually a style. It may occur singly or as one of a group.

Further Classification Vascular

• Have tissues that make up the organ system that carries water, nutrients, and other substances throughout the plants.

Nonvascular• Have no vascular tissue and use

other ways to move water and substance.

What it looks like?

Classifying Plants

Nonvascular, Seedless Plants: Small (usually only 2cm to 5 cm in height); Green stems; reproduces byspores, threadlike roots; grows in damp areas.

Vascular, Seedless, Plants: Reproduces by sporesoften found on the underside of the leaves; can bevarious sizes because they have vascular tissue

Vascular, Seed-bearing, Non-flowering, Non-fruitbearing: Vascular plants that produce seeds (usuallyfound in cones), do not have flowers, and typicallyhave needle or scale-like leaves.

Vascular, Seed-bearing, Flowering, and Fruitbearing, Monocot: Flower parts in multiples of three;leaves usually narrow and long; parallel veins; seedshave one cotyledon

Vascular, Seed-bearing, Flowering, and Fruitbearing,Dicot: Flowering parts in multiples of four orfive; leaves have a network of branching veins; seedshave two cotyledons

Plants Adaptation Adaptations help a plant to: · Get Sunlight, Water, Air, or Nutrients · Not be eaten · Stay put · Reproduce

Characteristics of Plants

• All plants are made up of eukaryotic cells.• They usually have leaves, stems and roots.• They vary in size and shape.• As plants evolved from aquatic to land

forms, they changed in structure and function. The changes included how they

reproduced, supported themselves and moved substances from one part of the plant to another.

Seedless Plants Seedless plants includes

nonvascular and vascular types. Bryophytes-mosses and liverworts –

are seedless nonvascular plants. They have no true leaves, stems,

roots, or vascular tissues and live in moist environments.

For bryophytes, reproduction is usually by spores.

Seedless Plants(con’t)

Bryophytes may be considered pioneer species because they are some of the first plants to grow in new or disturbed environments.

They change the environment so that other plants species can grow there.

o Club mosses, horsetails and ferns are seedless vascular plants.

o They have vascular tissues, a pipeline

o that moves substances throughout the plant.

Seedless Plants(con’t)

Like bryophytes, these plants may reproduce by spores.

Seed plants These plants have adapted to survive in

nearly every environment on Earth. Seed plants produce seeds and have

vascular tissue, stems, roots and leaves. Vascular tissues transport food, water

and dissolved substances in the roots, stems, and leaves.

Seed Plants(con’t)

The two major groups of seed plants are gymnosperms and angiosperms. Gymnosperms generally have

needlelike leaves and some type of cone.

Angiosperms are plants that flower and are classified as monocots or dicots.

Seed plants provide food, shelter, clothing, and many other products.

The Great Celery Experiment

Structure of a Flowering Plant

Reproduction During the process of fertilization,

pollen lands on the stigma, a tube grows down the style and enters the ovary. Male reproductive cells travel down the tube and join with the ovule, fertilizing it. The fertilized ovule becomes the seed, and the ovary becomes the fruit.

becomes the fruit.

Reproduction (cont.) Petals are also important parts of

the flower, because they help attract pollinators such as bees, butterflies and bats. You can also see tiny green leaf-like parts called sepals at the base of the flower. They help to protect the developing bud.

Pollination Pollination is the movement of pollen

from a stamen to a pistil. There are two types of pollination:

Wind-pollinated: a form of pollination where pollen is distributed by the wind.

Ragweed Insect-pollinated: a form of pollination

where pollen is distributed by insect, mostly bees. Entomophily is another name for insect pollination.

Rose sweet peas Viola Lily

Pollination (cont.)Flower part Insect-

pollinatedWind-pollinated

Petals large, brightly coloured petals - to attract insects.

small petals, often brown or dull green - no need to attract insects.

Nectary Usually contain nectar-to attach insects.

No nectar-no need to attach insects.

Scent often sweetly scented - to attract insects

no scent - no need to attract insects.

Stigma stigma inside the flower - so that the insect brushes against it.

stigma hangs outside the flower - to catch the drifting pollen.

Pollen moderate quantity of pollen - less wastage than with wind pollination.

pollen produced in great quantities - because most does not reach another flower.

anther anthers firm and inside flower - to brush against insects.

anthers loosely attached and dangle out - to release pollen into the wind.

Pollination (cont.) Cross-pollination: fertilization by

transfer of pollen from the anthers of one flower to the stigma of another flower.

Self-pollination: fertilization by transfer of pollen from the anthers to the stigma of the same flower.

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.

Plants are classified by characteristics.

Plants that make seeds Plants that do not make seeds

Flowering Plants

Conifers Ferns Mosses

Plants reproduce differently

Reproduce – it means “to make more of the same kind”

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.