Category Animal World

What come first-plant or animal?

               From time immemorial, the question of how this Universe came to be has haunted Man’s mind. While ancient Man chose to believe in the easiest answer that everything came into existence-through an act of God, modern science persisted with rational enquiries that proved otherwise. Have you ever wondered what it must have been like millions and millions of years ago, when the earth first came into existence? Were there plants and animals then?

               When the earth was first formed, there was no life on it. Its surface was extremely hot and had giant volcanoes that threw fiery rocks, dust, and gases into the air. Scientists estimate that the first life forms on Earth were primitive, single-celled organisms. They must have appeared about three billion years ago in the oceans. They had no bones or shells, so they looked more like worms and jellyfish. These one-celled organisms gradually became multi-cellular organisms. As time passed, more complex forms of life began to fill up oceans. One of the first forms of life was a very simple plant called algae. Different types of plants came later on. And so, yes, animal life appeared only after the appearance of plant life.

Picture credit: google

 
 

How do plants and animals differ from each other?

            You must have observed huge trees in your own backyard that have been staying in the same place for years, without any explicit signs of movement. Unlike animals, trees cannot move about, eat through the mouth, express emotions and communicate their needs. Plants and animals are as different from each other as a rose is from a rabbit!

            Generally, plants, with a few exceptions like the swimming algae, cannot move about from place to place, while animals can move freely. One of the most distinguishing features of plants is that they can make their own food with the help of their green colouring, which is called chlorophyll. On the other hand, animals must rely on plants for their food, or hunt other animals. Animals have a nervous system, which makes them sensitive to touch, heat, cold, pain, and other stimuli. Plants lack such a nervous system. However, as you must have observed, some plants such as the touch-me-not, do fold their leaves when touched. Others sense that a support is near, and twine themselves around it.

            The cell structure of plants and animals is different too. Most plants have rigid cell walls and contain cellulose. Animal cells do not have cellulose. The development of animals and plants is different too. While animals stop growing when they reach maturity, plants do not stop growing until they die!

 

 

 

 

 

 

 

 

 

 

 

Pictures credit: google

 
 
 

What is an animal?

            Life is what makes our planet different from the rest of the known universe. There are diverse forms of life on our planet. Living beings such as ants, beetles, fishes, sparrows, cats, dogs and cows have always fascinated us in several ways. Green plants like grass, shrubs, bushes and tall trees have also caught our imagination. While trees and plants are stationary, animals can move around.

            The word animal comes from the Latin word ‘anima’. It means ‘life’ or ‘breath’. Animals are living organisms, often belonging to a family or herd. They eat food, move about, and are capable of taking care of themselves. However, the simplest animals are very much like the simplest plants. Sometimes it is difficult to differentiate between the two.

            There are some telling differences between plants and animals. These are very clear when you look at the more highly developed animals. Plants have the ability to prepare their own food. However, animals eat plants or hunt down other animals. This characteristic of animals means that they have to be able to move about.

            On the other hand, things are not so clear-cut when you look at organisms that are made of only one cell. Sometimes, it is hard to tell if they are animals or plants. Bacteria, for example, can have characteristics of both animals and plants.

Picture credit: google