Question

Describe the basic life functions of plants and animals that they need to perform and the body structure (such as organ system or organs) that do those tasks?

Answer 1

The presence of certain fuctions and processes sustain life of an individual on the earth. There are many such several basic vital processes which are essential for proper functioning of the body organ system necessary for survival. These basic life functions are performed by organs or organ system and constitute the following life processes as follows:

(i) Nutrition- It is the process of intake of food and its distribution and metabolism for requirement of energy. The chemical substances present in food whicg act as a raw material for body building and maintaining its function are called nutrients. Green plants can directly utilize the energy of sunlight to synthesize organic molecules using carbon dioxide, water, etc via photosynthesis. The process of photosynthesis takes place in the mesophyll tissueof green leaves of plants and other green parts of plants like stem, etc. Chloroplast of mesophyll cells act as the major subcellular organelle of photosynthesis. Animals have heterotrophic mode of nutrition by which they derive organic food materials by consuming plant products. The alimentary canal along with mouth is the associated structures of nutrients intake and its metabolism. The accessory digestive organs like stomach, pancreas, intestine, liver, etc play an essential role in conversion of complex food substances to simple absorbable forms.

(ii) Transportation- Transportation and its related systems are different for animals and plants. In animals transportation of various substances occurs by the circulatory system which comprised of heart, blood, blood carrying vessels like artery, vein, capillaries, etc. Artery carry oxygenated blood away from the heart to cells and tissues while vein bring the deoxygenated blood towards the heart. Plants have vascular tissues which includes xylem and phloem that are responsible for the conduction and transportation of materials throughout the plant body. Xylem conducts water and minerals from roots to the shoot and other parts of plant like leaves, stem, etc while phloem conducts food prepared in leaves to other plant parts.

(iii) Metabolism- It is the sum total of all the chemical reactions taking place inside the body involved in controlling the physiological and biological state of the cells in an organism. It is basically two types, anabolism and catabolism. The former is the metabolic process which stores energy due to synthesis of a complex substance while the latter releases energy due to breakdown of the substance. Different cellular processes with its associated organelles participate in metabolic pathway.

(iv) Respiration- It involves the biological oxidation of organic molecules i.e breaking up of C-C bonds by using enzymes and results in the release of energy in the form of ATP. It takes place in the mitochondria of the cell with or without the presence of oxygen and as such it can be classified into aerobic and anaerobic respiration. The respiration in plants takes place by stomata which are tiny apertures found on the epidermis of leaves and young green stems. Animals have a variety of respiratory organs being adapted to different habitats. Exchange of gases i.e intake of O2 and release of CO2 occurs through lungs, gills, skin, etc.

(v) Reproduction- The biological process of producing offsprings which may or may not be identical to their parents so that the continuity of species is maintained, generation after generation is called reproduction. It is of two types- sexual and asexual reproduction. In plants, reproduction takes place asexually by budding, vegetative propagation, etc. They also reproduce sexually via pollination that transfer pollen grains from anther to stigma of the same or different flower of the plant. The male reproductive organs of flower is androecium or stamen while the female reproductive organs is called gynoecium or carpel. The animals on the other hand reproduce sexually whcih involves formation and fusion of gametes produced by two parents.

(vi) Excretion- The process of elimination of toxic waste substances from the body to outside is called excretion. Different modes of excretion are prevalent with different types of living species. Plants produce waste products in the form of gases like O2 and CO2. During photosynthesis oxygen is produced while carbon dioxide forms during respiration. The passage of removal of these gases occurs via stomata. Animals have a diversified excretory system consist of a pair of kidneys, one pair of ureters, a urinary bladder and a urethra. Kideneys are composed of structural and functional units called nephron that helps in ultrafiltration of blood and the purified blood is circulated to the entire body while the waste products extracted are passed into the ureters as urine. The urine is collected in the bladder from where it is excreted via urethra.

(vii) Locomotion- The movement which result in the change of place or location are called locomotion. It is an essential and significant feature of living organisms. Plants are rooted in the ground, so cannot move from one place to another while animals can move freely with the use of internal and external body parts. For example, amoeba uses pseudopodia for locomotion, humans uses limbs for changes in body postures and locomotion.