What is a plant?

Barbara10Broek By Barbara10Broek, 5th Jun 2011 | Follow this author | RSS Feed
Posted in Wikinut>Guides>Nature>Plants

Discusses the development of plants, how they produce food and grow.

Plants, The Key to Life?

To some plants are the key to life on earth. Without plants many other living organisms would soon disappear. This is because higher life forms depend on plants, either directly or indirectly, for their food. Most plants however are able to make their own food using sunlight. All plants fall into two basic categories. Flowering plants, which produce true flowers. The nonflowering plants include “primitive” plants, such as mosses, ferns, horsetails, and liverworts and the gymnosperms, a group of plants which include the conifers, like the giant sequoias. There are about a quarter of a million flowering species in the world today. They grow almost everywhere from snowy mountains slopes to arid deserts.

Forests of horsetails and giant club mosses once formed a large part of the earth’s vegetation. Club mosses can grow up to 150 feet (45 m) tall. During the last 300 million years their remains have been turned into the worlds large coal deposits.

It can be difficult to tell animals and simple plants apart. A plant like organism called the hydrozoan lives in the sea. It has branches that are formed by tiny animals called polyps. Polyps have tentacles to trap passing particles of food in the sea.

The living plant.

Flowering plants are busy throughout the day and night. During the hours of daylight the leaves collect the sun’s energy. The plant uses this trapped energy to create food in the form of sugars. The key to the way they do this is called chlorophyll which is what gives them their green color. Light is used to convert carbon dioxide and water into an energy rich sugar compound called glucose. As the food is produced it has to be transported away from the leaves. This is done in the night. As the glucose is produced it has to be transported away from the leaves to the places where it is needed. At the same time water and minerals which the roots had absorbed from the soil have to be carries in the opposite direction to the stems and branches. Water minerals and sugars are carried up and down a plant in tube like cells. One system called the phloem, can carry sugars upward or downward to the parts that need them.

Respiration, the way in which the plant breathes occurs throughout the 24 hours, just as with animals. As the plant matures it begins the complicated process of growing flowers, producing and receiving pollen and eventually producing and scattering seeds.

Life cycle

A seed is a tiny life support package. Inside is an embryo which consists of the basic parts from which the seedling will develop, together with a supply of food. The food is needed to keep the embryo alive and fuel the process of plant growth termed germination. This food is either packed around the embryo in an endosperm or stored in special leaves seed leaves called cotyledons. For weeks, months or even years the seed may remain inactive. When the conditions are right it comes alive and begins to grow. During germination the seed absorbs water, the cells of the embryo start to divide and eventually the seed case breaks open. The beginning of the root system, or radical, sprouts and grows downward. Rapidly a shoot, or plumule begins to grow upwards towards the sun to create leaves and the cycle of plant life starts over again.


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author avatar Barbara10Broek
Professional Librarian and freelance writer. Home Page: http://barbaratenbroekfreelancewriter.yolasite.com/

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author avatar Amy
26th Jul 2011 (#)

To 'Barbara' ,
I am contacting to inform you that you have plagiarised 'Plant' by David Burnie, first published 1989, Dorling Kindersley Limited, London.

On behalf of Dorling Kindersley Limited, we request for you to terminate this page or alter the plagiarised sections in the next 72 hours. If you do not abide, you will be subjected to incur a hefty penalty.


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