Tag: diffusion

Photosynthesis is the process by which green plants make their own food from carbon dioxide and water in the presence of sunlight. The prepared food is glucose. To prepare one molecule of glucose, by the process of photosynthesis six molecules of carbon dioxide and six molecules of water is required. Six oxygen molecule is released as a waste product. This oxygen is produced due to splitting of water by the process of photolysis during light reaction. So, the correct answer is option 'Oxygen'.

In physiology, respiration is defined as the movement of oxygen from the outside air to the cells within tissues, and the transport of carbon dioxide in the opposite direction. The physiological definition of respiration should not be confused with the biochemical definition of respiration, which refers to cellular respiration. The metabolic process by which an organism obtains energy by reacting oxygen with glucose to give water, carbon dioxide and 38 ATP (energy). Although, physiologic respiration is necessary to sustain cellular respiration and thus life in animals, the processes are distinct: cellular respiration takes place in individual cells of the organism, while physiologic respiration concerns the bulk flow and transport of metabolites between the organism and the external environment. 

Lenticels are involved in gaseous exchange between internal tissues and atmosphere. These are porous tissues present in periderm that are developed during secondary growth.

The highest rate of respiration are found in the actively growing root and stem tips, cambium and embryos of germinating seeds and lowest rates in dormant seeds or spores. As, the growing tips are generally rich in meristematic tissues the rate of respiration is also high.

Out of all the options given the third option is the correct one.
Exchange of gases is a feature that is common in all living things. Irrespective of the genera of living organisms,  all organs that exchange gases are characterized by features such as- thin, moist, large surface area and a large capillary network.

All parts of the plant respire, the leaves, the stem, the roots and even the flowers. The parts above the soil get their oxygen directly from the air through pores. The pores in the leaves are called stomata. The pores in stems of trees are called lenticels.

Photosynthesis does not take place in plants during night time as the sunlight is absent and the accumulation of carbon dioxide is more. we feel suffocated if we sleep under trees during night times are more carbon dioxide is present around the trees.

Source and sink are important concepts in translocation in plants. In plants, organic solutes are translocated from regions of their synthesis like green leaves or storage organs like tubers in stem and roots to the region of their active utilisation like the regions of active growth at tips of stem and roots. Thus green leaves and storage organs act as source, whereas regions of active growth act as sink for organic solutes.