plants

WHAT PLANTS ARE



Plant are any number of the plant kingdom,with about 260,000 known species of
mosses, liver work, ferns, harbeceous and woody plants, bushes, vines, trees,
and other forms that mantle the Earth and are also found in its waters. Plants
increase in size from small. Though the first plants appeared on land only about
a half a billion years ago, today they account for by far the largest proportion
of the earths biomass.

Only a small amount of percentage of percentage of plant species are directly
used by humans for food, shelter, fiber, and drugs. The head of the list are
rice, wheat, corn, cotton, conifers, and tobacco. on which alot of people depend
on.











DIFFERENT KINDS OF PLANTS

Scientist know that there are more than 250,000 different kinds of plants. If
we went around the world we would see alot of different kinds of plants. There
are four different important groups of plants the group in which in which the
simplest plants are found includes one-celled bacteria, and fungi that are like
the molds that are often found seen growing on bread and cheese. In this same
group are probably the longest which are called seaweed. These are called
thallophytes.

Another group of relatively simple plants includes the mosses and liveworts
that are found in forest, on rocks and leaves, but they have no roots. They are
called bryophytes. A third group of plants includes the ferns, quillworts , and
clubmosses.

They are periodphytes. Most of the plants we know belong to the group of
plants are called spermatophytes, or seed-bearing plants. That includes like
grass, vegetables, trees, shrubs, flowers and alot more.





WHAT PLANTS NEED TO GROW



Plants need their roots, leaves, and their stems. That\'s what they need to
grow straight and healthy. They also need their sunlight but others need little.
Some need water and nutrients, others need moisture with minerals.

Plants make their own food by sucking up all the water and traveling it up
through the stem to the flower.

Leaves make their own food under themselves. But the most plants depend on is
the sun.















ROOTS



The roots purpose is to hold up the plant up and to absorb the water and
minerals.

Roots are found underground and grow down. They have no stems or leaves
attached.

The epidermis is just behind the growing tip of the root that is covered with
root hairs, which are the growth of the epidermal cells. The root hairs push out
the dirt around it and suck up the water and nutrients.

Roots need xylem and plhoem, although many are highly modified to carry out
different kinds of functions. The roots are the most important food organs.
Epiphytes have roots made for absorbing rain water that flows down the back of
the plants.









LEAVES



The leaf is the organ of most plants. Leaves are the organs sticking out of
the stem. They are made up of loosely arranged cells with air, were cells absorb
carbondioxed and goes in in and then they release oxygen.

The mesophyllis held together bay the upper and lower surface of the leaf,
which is covered by tissue. A vascular runs through the mesophyll providing the
cells walls with water and taking out the food the produces of photosynthesis to
other parts otf the plants. The leaf blade is connected to the stem through a
thin portion called the petiole, or stalk, which consist mostly of flowers -carpels.
The individual parts and sepals are all modified leaves that have taken on
reproductive functions.

Category: Science