Animals vs Plants
Organisms are of two main types animals and plants, although all the above mentioned Unifying concepts of Biology apply equally to both animals and plants, yet animals and plants differ in several important respects as follows:
1. Cell structure: Every living cell is bounded by an extremely thin and elastic, living membrane, called plasma or cell membrane. Plant cells possess an additional thick inelastic and non living cell wall outside the plasma membrane. This cell wall is formed of a carbohydrate called cellulose. Due to its presence, plant cells have faces shapes and no flexibility unlike animal cells, plant cells typically contain large vacuoles filled with a watery fluid called cell sap unlike plant cells, and animal cells possess a division centre or centrosome near the nucleus. Unlike animal cells, most plant cells possess a special type of organelles. Called, chloroplasts which contain the green pigment chlorophyll.
2. Growth: Some embryonic reserve tissues persist throughout life in the plants. That is why plants continue growing and forming new parts throughout life and become branched. In animals, embryonic, tissues are used up early. Hence, news organs cease to form after embryonic development and the body continues only up to a certain age. And the power of regeneration of lost or damaged parts is very poor in comparison to the plants.
3. Locomotion and movement: Most animals can move about from place to place and can also move parts o their bodies. Excepting a few lower forms, plants are usually fixed in the ground by means of roots and, hence, immobile. Some spontaneous movement is, however, exhibited by some of their parts, such as the leaves and flowers.
4. Body Organization: As compared to the animals, plants have a simpler body organization with a fewer types of organs such as roots, stem, leaves and flowers.
5. Nutrition: The most important difference between plants and animals concerns their nutrition. Carbohydrates, fats and proteins are the major nutrients' for all organisms. Plants synthesize these organic nutrients from their inorganic constituents obtained from the environment. This called photosynthesis, because it occurs in presence of sunlight with the help of chlorophyll. Animals have no chlorophyll and hence, cannot synthesize the nutrients. Obviously, the nutrition of plants is thus autotrophic, while that of animals is heterotrophic holistic
6. Trapping of solar energy: Sunlight is the only source of energy required for synthesis of organic nutrients upon present earth. This solar energy is a kinetic energy .Only green plants can trap it Inc c or c h bonds with the help of chlorophyll in photosynthesis, synthesizing carbohydrates and then, the other macronutrients from carbohydrates.
7. Irritability: Plants have poorer responsiveness to environmental changes Hence, their responses are extremely slow, minimal and indistinct, Responsiveness in animals is well evolved and accompanied with the evolution of a nervous system to help in it.
8. Storage of carbohydrates: Animals store carbohydrates in the form of glycogen, while plants store these as starch.