Difference between Plant Cell and Animal Cell | Biology

The upcoming discussion will update you about the difference between plant cell and animal cell.

Difference # Plant Cell:

1. The plant body usually bears branches. The palms, the Cycas and a few others are exceptions.

2. Majority of the plants, with the exception of fungi and bacteria, are green in colour due to the presence of chlorophyll. Plant cells, excepting those of the fungi and the bacteria, possess protoplasmic bodies called plastids. Of the three kinds of plastids, the chloroplasts contain the green pigment chlorophyll which occupies the most strategic position in the living world.

3. The protoplasm of the plant cell is usually surrounded by a rigid non-living cell wall composed of cellulose. This is an insoluble carbohydrate secreted by the protoplasm. In course of time the protoplasm itself may disappear and only the non-living cell wall is left behind. Such a cell is obviously dead.

4. Vacuoles are present in plant cells. These are intracellular vesicles containing watery cell sap. Very often the vacuoles become so large that they occupy the major portion of the cell.

5. A central body is rarely found in plant cells.

6. Most plants, excepting a few lowly ones, are fixed to the soil by roots or root-like structures. They, therefore, have no power of locomotion.

7. Plants can move parts of their body in response to external stimuli; but as they have no nervous system, the movement is slow in their case. Sensitive plant is an exception, because it responds quickly to touch.

8. Green plants absorb water with dissolved minerals from the soil and carbon dioxide gas from the air. With the help of chlorophyll, which they possess, they can synthesize complex carbohydrate food out of the two simple raw materials, carbon dioxide and water. This process is known as photosynthesis, because it always occurs in the presence of sunlight.

In manufacturing proteins and fats, the carbohydrates form the ground substance. Thus the green plants can manufacture all the three important food substances, carbohydrates, proteins and fats. They, therefore, are said to be autotrophic or holophytic in their mode of nutrition. They can live in a world devoid of animals.

9. As already stated, plants absorb raw materials in liquid or gaseous forms. They cannot ingest solid food. The insectivorous plants are exceptions, because they capture insects and obtain a part of their proteins by digesting the latter.

10. When required, plants digest their food bit by bit leaving no solid residue for egestion.

11. Metabolism in plants is predominantly anabolic. They are constantly trying to build and store food substances. The result is that plants grow indefinitely till almost the last days of their lives.

12. Plants do not possess special excretory organs for eliminating their nitrogenous waste products. They utilise most of the nitrogenous substances for building proteins. The little that remains is transferred to barks, leaves, etc., and is thrown out that way.

Difference # Animal Cell:

1. The animal body usually does not bear branches. The Ohelia and a few plant-like hydroids are exceptions.

2. Majority of the animals, except­ing lowly forms like Euglena, are not green, because they have no chlorophyll. Some animals, however, such as grasshoppers, may acquire chlo­rophyll from plants for the purpose of camouflage which ensures protection from enemies.

Plastids, particularly chloroplasts, are usually absent in animal cells.

3. A cell wall composed of cellu­lose is not found in the animal cell. As a rule, the animal cell is covered by a thin and elastic limiting membrane called plasma lemma which is composed of protoplasm. A non-living cell wall may be secreted by the protoplasm of the animal cell but this is always thin and is not composed of cellulose.

4. Vacuoles are scarce except in the protozoan cell body. When present they are much smaller in comparison to those found in plant cell.

5. A star-shaped central body is usually present in animal cells. It lies near the nucleus and plays an important part during cell division.

6. Most animals have the power of locomotion. They can move from place to place in search of food. There are some, such as sponges, corals and sea- anemones which are fixed and plant-like.

7. Animals, as a rule, can move their body parts quickly in response to external stimuli, because majority of the animals possess a nervous system for producing nervous co-ordination.

8. Animals, having no chloro­phyll, cannot manufacture their food. They are directly or indirectly dependent on plants for the supply of proteins, fats and carbohydrates. So the animals are heterotrophic or holozoic in their mode of nutrition. They cannot conti­nue to live in a world devoid of plants.

9. Animals, excepting a few parasites such as tapeworms, ingest solid food. They cannot utilise gaseous raw materials like the plants. The green Euglena is an exception.

10. Animals cannot digest all the solids which they ingest. A residue is always left behind which is required to be egested.

11. Metabolism in animals is pre­dominantly katabolic, because more active habit requires con­stant release of energy by the depletion of food. The result is that there is a definite growth period after which animals cease to grow.

12. Animals have special excretory devices for eliminating nitro­genous waste products. Sub­stances like ammonia and urea are constantly formed in the animals body by the depletion of proteins. These substances are promptly thrown out by the excretory channels i before they can do any harm.