5. How are fats digested in our bodies? Where does this process take place?
6. What is the role of saliva in the digestion of food?
7. What are the necessary conditions for autotrophic nutrition and what are its by-
products?
8. What are the differences between aerobic and anaerobic respiration? Name some
organisms that use the anaerobic mode of respiration.
9. How are the alveoli designed to maximise the exchange of gases?
10. What would be the consequences of a deficiency of haemoglobin in our bodies?
11. Describe double circulation of blood in human beings. Why is it necessary?
12. What are the differences between the transport of materials in xylem and phloem?
13. Compare the functioning of alveoli in the lungs and nephrons in the kidneys with
respect to their structure and functioning.
e Processes
Answers
Q5) The large globules of fats are broken down by bile salts into smaller globules. The pancreas secretes pancreatic juice which contains lipase for breaking down emulsified fats. The enzymes in intestinal juice finally converts these fats into fatty acids and glycerol. The process takes place in small intestine.
Q6) Saliva is 98% water, so it moistens the mouth and helps compact food into softened particles for easier swallowing. ... It's important to chew your food as much as possible, as taking longer to chew gives the enzymes in saliva time to begin the process of breaking down carbohydrates, a very important part of digestion.
Q7) Autotrophic nutrition takes place through the process of photosynthesis. Carbon dioxide, water, chlorophyll pigment, and sunlight are the necessary conditions required for autotrophic nutrition. Carbohydrates (food) and O2 are the by-products of photosynthesis.
Q8) Anaerobic respiration
Exchange of gases is does not happen.
It occurs only in cytoplasm.
End products vary.
Q9) The alveoli are thin-walled and richly supplied with a network of blood vessels to facilitate the exchange of gases between blood and the air-filled in alveoli. They have a balloon-like structure that provides maximum surface area for exchange of gases.
Q10) Haemoglobin is the respiratory pigment that transports oxygen to the body cells for cellular respiration. Therefore, deficiency of haemoglobin in blood can affect the oxygen supplying capacity of blood. This can lead to deficiency of oxygen in the body cells. It can also lead to a disease called anaemia.
Q11) This means that during a single cycle, the blood goes twice in the heart. This double circulatory system is important because it ensures provision of oxygenated blood to the muscle and not a mixture of oxygenated and de-oxygenated blood. Hence, this system ensures efficient supply of oxygenated blood to the muscles.
Q12)Xylem tissue helps in the transport of water and minerals. Phloem tissue helps in the transport of food. Transport in xylem occurs with the help of simple physical forces such as transpiration pull. Transport of food in phloem requires energy in the form of ATP.
Q13) Alveoli and nephron act as the structural and functional units of lungs and kidneys respectively. Alveoli occur in the respiratory system while the nephrons occur in the excretory system. The cell wall of alveoli and nephrons is thick and surrounded by blood capillaries.
5. Fat digestion takes place in the small intestine. The alkaline secretion of the liver, bile, is carried to the small intestine by the bile duct. The process starts with emulsification (break down) of large fat globule by the salt of bile into smaller micelles to facilitate further enzymatic reaction and digestion process.
6. The role of saliva in the digestion of food is
1: It moistens the food for easy swallowing.
It contains a digestive enzyme called salivary amylase, which breaks down starch into sugar.
2: Lubricates and moistens food, thus aiding in swallowing
3: Aids in food particles to stick together for the formation of the bolus, so that they cab swallowed as a mass.
7. Autotrophic nutrition takes place through the process of photosynthesis. Carbon dioxide, water, chlorophyll pigment, and sunlight are the necessary conditions required for autotrophic nutrition. Carbohydrates (food) and O2 are the by-products of photosynthesis.
8. 8th answer is in the attachment
