Nutrition: A process to transfer a source of energy from outside the body of the organism, which we call food, to the inside, is called nutrition. For Example Respiration (R), Excretion (E), Nutrition (N), and Transportation (T). Nephrons act like transit point for blood capillaries.Įxchange of materials takes place through diffusion.Įxchange of materials takes place due to high pressure.Life Processes: The processes which together perform the repair and maintenance job inside a body are life processes. Nephrons are networks of very fine tubules.Īlveoli have network of blood capillaries on their walls. Question 13: Compare the functioning of alveoli in the lungs and nephrons in the kidneys with respect to their structure and functioning. The transport in phloem is an active transport as it requires energy. Transport in phloem: The transport in phloem is bidirectional and food and some other products are transported. Through xylem only water and minerals are transported.
This is a kind of passive transport as no energy is required. Question 12: What are the differences between the transport of materials in xylem and phloem?Īnswer: Transport in xylem: The transport in xylem is from roots to upwards and takes place in only one direction. This is necessary for optimum oxygen utilization as humans are warm blooded animals and need extra energy to maintain their body temperature. Because of this the blood passes twice through the heart in one cycle of circulation hence the name double circulation. Why is it necessary?Īnswer: In double circulation there is complete segregation of oxygenated and deoxygenated blood. Question 11: Describe double circulation in human beings. Finally person’s health will deteriorate. This will, in turn lead inefficient utilization of food by the body. Deficiency of haemoglobin will lead to less supply of oxygen to different cells. Question 10: What would be the consequences of a deficiency of haemoglobin in our bodies?Īnswer: Haemoglobin is the carrier of oxygen in blood.
Question 9: How are the alveoli designed to maximise the exchange of gases?Īnswer: The wall of alveoli contains a fine network of blood capillaries. Yeast and bacteria use anaerobic mode of respiration. In anaerobic respiration there is incomplete oxidation of glucose and the end product is either lactic acid or alcohol. Question 8: What are the differences between aerobic and anaerobic respiration? Name some organisms that use the anaerobic mode of respiration.Īnswer: In aerobic respiration there is complete oxidation of glucose and the end product is water and carbon dioxide. Question 7: What are the necessary conditions for autotrophic nutrition and what are its byproducts?Īnswer: Conditions necessary for photosynthesis: Sunlight, carbon dioxide and chlorophyll. Question 6: What is the role of saliva in the digestion of food?Īnswer: Saliva contains the enzyme amylase which breaks complex molecules into sugar. The enzymes present in it finally convert fats into fatty acids and glycerol.
The walls of the small intestine contain glands which secrete intestinal juice. The pancreas secretes pancreatic juice which contains enzyme called lipase for breaking down emulsified fats. Bile salts break them down into smaller globules increasing the efficiency of enzyme action.
Question 5: How are fats digested in our bodies? Where does this process take place?Īnswer: Fats are present in the intestine in the form of large globules which makes it difficult for enzymes to act on them. Question 4: The breakdown of pyruvate to give carbon dioxide, water and energy takes place in Question 3: The autotrophic mode of nutrition requires Question 2: The xylem in plants are responsible for
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