Roots obtain oxygen from air in the soil for respiration. In the absence or deficiency of `O_2` root growth is restricted or completely stopped. How do the plants growing in marsh lands or swamps obtain their `O_2` required for root respiration?

Respiration requires O2. How did the first cells on the earth manage to survive in an atmosphere that lacked O2?

Complete the paragraph by choosing the words given in the bracket : (rhizoids, spore, water, thalloid, amphibians, conduction) Bryophyta is the group of plants known as‘.........' of the plant kingdom because they grow in moist soil but need ......... for reproduction. These plants are .......... multicellular and autotrophic. They reproduce by ......... formation. The structure of the plant body of bryophytes is flat, ribbon-like long. They have stem-like or leaf-like parts and root-like vases They do not have specific tissues for ......... of food and water.

Read the following paragraph and answer the questions based on it. Rhizobium produce nitrogenous compounds from atmospheric nitrogen. However, for this process of nitrogen fixation, they need leguminous plants like beans, sweet pea, soyabean, etc. as ‘host’. Rhizobium living in root nodules supply nitrates, nitrites and amino acids to that plant and in exchange get energy in the form of carbohydrates from it. Such a mutually beneficial relationship is called symbiosis. Beans and pulses are rich in proteins due to the nitrogenous compounds made available by Rhizobium. After harvesting a leguminous crop, the left-over roots and other plant parts are deliberately dumped in farm soil to maintain its bacterial population. The use of Rhizobium has helped to reduce the use of chemical fertilizers and thereby their adverse effects. It has also helped to reduce expenses on fertilizers and thus works to the benefit of farmers. How do the soil conditions improve by Rhizobium?

The countries which do not have oil reservoirs in their land import oil from other countries. But sometimes during transporting oil through sea routes, accidental oil spilling occurs. This oil spilled in the ocean may prove fatal and toxic to aquatic animals. Therefore, removel of this spilled oil is essential for protection of aquatic life. For removing this oil layer, certain microbes like Pseudomonas spp. and Alcanivarax borkumensis are used. These microbes have the ability to destroy the pyridines and other toxic chemicals. The hydrocarbonoclastic bacteria (HCB) are able to decompose the hydrocarbons and bring about the reaction carbon with oxygen resulting in formation of C O 2 and water. Like oil spills cause damage to aquatic life. plastic forms the major part of the garbage on land. Plastics are difficult to degrade as they are made up of PET. By research, various species like Vibrio and Idenoella sakaiensis which can degrade PET have been identified. There are certain species of microbes which can decompose rubber from garbage. Based on the given paragraph answer the following question.Why should there be a ban on plastic bags ?

complete the paragraph by choosing the appropriate words given in the brackets : (external, inhalation, alveolar, breathing, resptration, exhalation) Release of energy from the assimilated food is called .......... Inhalation and exhalation is called ................. When.............. is done, air enters the lungs. The oxygen from this air enters the blood while carbon dioxide from the blood exits from the blood, Through .................. CO_2 is given out. This gaseous exchange occurs through ......... membrane. This is called................ respiration. The RBCs carry oxygen to every cell.

Dihydrogen gas is obtained from natural gas by partial oxidation with steam as per following endothermic reaction, CH_4(g) +H_2O(g) hArr CO(g) + 3H_2(g) How will the values of K_p and composition of eauilibrium mixture be affected by increasing the P

The quantity of charge required to obtain onb mole of aluminium from Al_2O_3 is

Dihydrogen gas is obtained from natural gas by partial oxidation with steam as per following endothermic reaction, CH_4(g) +H_2O(g) hArr CO(g) + 3H_2(g) How will the values of K_p and composition of eauilibrium mixture be affected by Inceasing the T

Dihydrogen gas is obtained from natural gas by partial oxidation with steam as per following endothermic reaction, CH_4(g) +H_2O(g) hArr CO(g) + 3H_2(g) How will the values of K_p and composition of eauilibrium mixture be affected by using a catalyst