Lesson 24

What are the characteristics of plants?

Plants are pretty to look at. We decorate our homes with them.

We work hard to grow gardens

And have thick lawns.

Sometimes, we give flowers to our loved ones.

Plants give us pleasure, but most important:

Without plants, there could be no life on earth!!

Plants give us oxygen.

They give us our food.

All the food we eat comes from plants, either directly or indirectly.

Figure these out:

Why wouldn’t we still have cows, pigs and chickens to eat if there were no plants?

You probably recognize a plant when you see one. However, as you have already learned, some algae look like plants. How can you tell if an organism is a plant or not?

All plants have these characteristics:

- Plants have many cells.

- The cells of plants form tissues and organs.

- Plant cells are surrounded by a rigid cell wall, made of cellulose. It gives plants their stiffness.

- Plants make their own food

Plants make their own food using the chlorophyll stored in the cell’s chloroplasts.Most food making takes place in the green leaves of plants.

The leaves are often called “the plant’s food factory.

The plant kingdom is divided into two large groups, called phyla.

Vascular plants:

Belong to the division tracheophyta.Have stems, roots and leaves.

Have a vascular system (connecting tubes) which carry water and dissolved nutrients to all parts of the plants.

Vascular plants are the most complex plants. Most of the plants you know belong to this group of plants.

ferns trees roses

And other flowering plants

Nonvascular Plants:

Belong to the division bryophyta.

They are very simple plants.

Do not have true roots, stems, or leaves.They have no vascular system.

This group includes:

mosses liverworts hornwarts

Most plants reproduce by seeds.

All seed plants are vascular plants.

Biologists classify seed plants into two groups.

gymnosperms

Uncovered seeds.

Most common are evergreens which produce cones

angiosperms

Are flowering plants.

Most flowering plants are easy to recognize, like roses and tulips.

Did you know that grasses, oak trees, and corn are flowering plants?

Their flowers are very small and hard to see.