Difference between photosynthesis and respiration:

Difference between cellular respiration and breathing

Plants take in oxygen and give out carbon dioxide. In the cells, oxygen is used to breakdown glucose into carbon dioxide and water as in other organisms. In plants each part can independently take in oxygen from the air and give out carbon dioxide.
 
Leaves of the plants have tiny pores called stomata for exchange of oxygen and carbon dioxide. Like all other living cells of plants, the root cells also need oxygen to generate energy. Roots take up air from the air spaces present between the soil particles. The stems of some plants have tiny pores called lenticels which help in exchange of gases.

A cockroach has small opening on the side of its body. These openings are called spiracles. Insects have a network or air tubes called tracheae for gas exchange, oxygen rich air rushes through spiracles into the tracheal tubes, diffuses into the body tissues and reaches every cell of the body. Similarly carbon dioxide from the cells goes into the tracheal tubes and moves out through spiracles. These air tubes or tracheae are found only in insects

The fishes have special type of organs for respiration called gills. These gills absorbs oxygen dissolved in water and through blood vessels, this oxygen is passed to all the parts of the body. The amount of dissolved oxygen is comparatively less in water than the amount of oxygen in air. Therefore, the rate of breathing is also high in aquatic animals.
If we add warm water, to the aquarium the dissolved oxygen will dissociate and move into the atmosphere again, leaving the least percentage of oxygen into the water (as it is known that the solubility of gases in water goes down as the temperature rises). Therefore, fishes will have difficulty in breathing in the absence of oxygen and will die.

(a) Animals that can breathe only through skin are earthworm and leech.
(b) Animals that can breathe through skin as well as through lungs are frogs.
(c) Animals that can breathe through lungs are buffaloes, human, and dolphins.
(d) Animals that can breathe through gills are tadpole and fish.
(e) Animals that can breathe through spiracles and tracheae are grasshopper, cockroaches, ants, housefly and mosquito.

(a) Respiration is the process of breakdown of food to produce energy for performing various functions. It involves two major steps:
(i) Inhalation is the process of taking in of air which is rich in oxygen, inside our body.
(ii) Exhalation is the process of giving out of air which is rich in carbon dioxide from our body to the external environment.
(b) The number of times a person breathes, in a minute is called as breathing rate. An adult human being can inhale or exhale 15-18 times in a minute. It is the average breathing rate of an adult human being. Breathing rate is not constant always.

During day, plants photosynthesise in the presence of sunlight and uses CO₂ produced during respiration. During this process O₂ is released as a byproduct and a balance between O₂ and CO₂ is maintained in the atmosphere. But in the night. plants do not photosynthesise. Plants are unable to use CO2 during night and produces CO₂ and takes O₂ during respiration. This leads to the increase in the proportion of CO₂ in the air.
So, if one sleeps under a tree at night. he will have problems in breathing as the amount of CO₂ in the air around will certainly be more than oxygen. Therefore, it is not advisable to sleep under trees during night because the person will suffer from suffocation and feel excess weight on chest.

(a) Paheli had cramps in her leg muscles after running. She felt pain in her legs because of accumulation of lactic acid in the leg muscles. Lactic acid is formed due to anaerobic respiration in the muscle cells after heavy exercise or running. After heavy exercise, we require large amount of energy.
To produce more energy to meet the oxygen requirement of muscles, muscle cells perform anaerobic respiration for a short duration. Lactic acid is formed due to partial breakup of glucose. It gets accumulated in the muscle cells and causes pain and muscle cramps.
(b) The massage or hot water bath gives the relief from muscle cramp or pain, because it improves the circulation of blood leading to increase supply of oxygen to the muscle cells . It helps in complete breakdown of lactic acid into carbon dioxide and water

(a) The dough rises due to the release of carbon dioxide during anaerobic respiration by yeast cell.
(b) Yeast, during anaerobic respiration also produces alcohol which results in the sour smell of dough.
(c) Sugar is added into the dough, because it acts as a food for yeast. Yeast upon incomplete breakdown of sugar or food produces CO₂, alcohol and energy (in less amount).
(d) If the dough is kept in the refrigerators after it was prepared, then dough will neither raise nor become sour. Yeast requires high temperature to grow, multiply and to respire. At low temperature, the yeast will not respire to produce the byproducts of anaerobic respiration.