PLANTS

Roots buried under the ground help keeps plants from blowing away helps keeps plants from being swept away by rainstorms

Roots also give a plant the water it needs.

Protects the tip of a root as it grows and moves through soil. ROOT CAP Protects the tip of a root as it grows and moves through soil.

There are two main kinds of roots.

Fibrous roots are thin and have many branches.

Tap roots are large, thick roots with fine roots called root hairs branching off them.

STEMS

Carry water and minerals absorbed by roots to leaves and flowers. STEMS Carry water and minerals absorbed by roots to leaves and flowers.

Stems also carry sap, made by leaves, down to all parts of the plant.

Sap is the sugary food plants make to nourish themselves and stay alive.

Inside the stem are long bundles of tiny tubes which carry water and food.

One bundle, the xylem, carries water and minerals from the roots to the leaves. It also supports the great bulk of the plant.

The phloem bundles carry food (carbohydrates) from the leaves to the rest of the plant.

VEINS IN STEMS

LEAVES

Types of leaf shapes simple and compound

Simple leaves have 1 blade (or body) attached to a stem.

A compound leaf has several blades all attached to the same stem.

Identify the following leaves as: Simple or Compound A B C D E Simple Compound Compound Simple Simple

All leaves have a network of veins running through them.

VEINS carry water and mineral from root and stem to leaves carry food that the leaves make to the rest of the plant

2 types of veins Parallel veins run the same direction as the leaf. Netted veins branch out at all angles to cover the entire leaf.

PHOTOSYNTHESIS

Plants can make food just from air, water, and sunlight.

To make food from air, plants need the carbon dioxide that animals exhale.

Green plants have a special chemical in their leaves called chlorophyll.

Chlorophyll lets the plant use the energy from the sun shining on its leaves to make food out of carbon dioxide and water.

Chlorophyll is what makes leaves green.

A plant’s way of making food is called photosynthesis.

During photosynthesis, plants produce a kind of sugar.

Plants and animals supply the requirements of life to each other.

Animals breathe in oxygen and exhale carbon dioxide, a gas poisonous to them.

Plants take carbon dioxide from the air, turn it back into oxygen, which it releases into the air.

Plants breathe through little microscopic holes on the bottom of the leaves.

These holes are called stomata

stomata viewed under an electron microscope

FLOWERS

The sepal is the bottom layer of petals, which are colored green like the stem and covered in a stiff, waxy coating to help protect the growing flower bud before it blooms.

SEPAL SEPAL SEPAL SEPAL

At the center of the flower is the vase-shaped pistil.

The pistil is the female part of a flower.

3 PISTIL PARTS stigma style ovary

At the bottom of the pistil in the ovary are some ovules.

These are the seeds that are not developed yet.

The stamen are arranged around the pistil.

They are the male part of the plant.

3 MALE PARTS stamens filaments anthers

On the end of thin stalks called filaments are the anthers.

They make a yellow powder called pollen.

To make seeds, the male pollen has to fall into the female pistil To make seeds, the male pollen has to fall into the female pistil. This is called pollination.

When the pollen joins with the ovules to make seeds it is called fertilization.

Many flowers make the sweet liquid called nectar.

As insects drink nectar, they become coated with pollen.

When the pollen from one plant is carried to another plant of the same type, it is called cross-pollination.

Some plants have flowers that pollinate themselves Some plants have flowers that pollinate themselves. This is called self-pollination.

Wind-pollinated plants shed millions of small, male pollen grains into the air. Few will find a female plant to fertilize, however.

Some plants reproduce by sending out shoots called runners.

Wherever, runners touch the soil, they develop roots and grow into new plants.

When no male or female parts are needed to reproduce, it is called vegetative reproduction.

Gymnosperms plants that do NOT produce flowers examples: conifers, woody trees, and shrubs

Angiosperms flowering plants

2 classes of flowering plants monocots dicots

MONOCOTS flowering parts in 3’s or multiples of 3 long, tapering leaves with parallel veins vascular bundles are scattered

Examples of monocots are grasses, orchids, irises, onions, lilies, and coconut palms.

DICOTS Floral parts in 4’s or 5’s or multiples of 4 or 5 broad to narrow leaves with netted veins vascular bundles are arranged in a circle

Examples of dicots are roses, cacti, blueberries, sunflowers, and oaks.

Plant’s response to stimuli

The term "tropism" refers to a plant’s movement triggered by stimuli.

In phototropism the roots, leaves and other parts of a plant growth are affected by a light source.

Hydrotropism refers to the directional growth of a plant’s parts toward a water source.

The term geotropic refers to a plant whose roots grow down into the soil as a response to gravity.

Transpiration is the process by which water evaporates from a leaf.

TREES

Green stems die at the end of each growing season Green stems die at the end of each growing season. Tree stems (trunks) keep growing from year to year.

The outside of a tree trunk is called the bark The outside of a tree trunk is called the bark.It protects the growing part of the tree.

The second layer is the cambium, where the new bark is growing.

The cambium carries food made by the leaves to all parts of the tree.

The ring of light and dark wood shows one year of a tree’s growth.

The next layer in from the cambium is the sapwood.

The sapwood carries water and minerals up from the roots to the rest of the tree.

The center of the tree is a hard dead core called heartwood.

The heartwood no longer carries any food or water, but it makes the tree strong.

A tree keeps getting larger and larger, adding rings to its trunk, for as long as it lives.