1. What type of nutrition does an amoeba have? 1
2. What are villi ? State its function also. 2
3. (i) What is the role of acid in stomach ? 2
(ii)What is emulsification of fats?
4. (i)Define Rancidity. 2
(ii) How will you prevent food from getting spoiled by the above said process.
5. Define term decomposition reaction .Give an example of each thermal
decomposition and electrolytic decomposition reaction . 3
6. (a) Draw well labelled diagram of human digestive system .
(b) Name the substances on which the following enzymes act in the human digestive
system: 1) Trypsin 2) Amylase 3) Pepsin 4) Lipase 5
7. (a) Why is small intestine in herbivores longer than in Carnivores?
(b) What will happen if mucus is not secreted by the gastric glands?
(c) Name the pigment which can absorb sunlight energy.
(d) Write the function of liver in human digestive system. 5
8. A) What is nutrition and why is it necessary for the Human body?
b) What causes movement of food inside the alimentary canal?
c) Write the function of Pancreas in human digestive system. 5
Answers
Answer:
1> Amoeba has holozoic type of nutrition.
Answer:
Explanation:
1. Ameoba's nutrition is Holozoic, solid food particles are ingested which are then acted upon by enzymes and digested.
2. Villi are finger type projections that are present on the surface of the small intestine. They help to increase the surface area of the small intestine, they absorb water from the waste food material and they allow the material to enter into large intestine.
3.(i) In stomach acids such as Hydrochloric acid (HCl) help to kill bacteria and to aid digestion by solubilizing food.Stomach acid activates the enzyme pepsin needed for protein digestion.
(ii) Emulsification of fats means breakdown of fat globules in the duodenum into tiny droplets, which provides a larger surface area on which the enzyme pancreatic lipase can act to digest the fats into fatty acids and glycerol. This process is assisted by the action of the bile salts.
4.(i) When the substance containing oils and fats are exposed to air they get oxidised and become rancid due to which their smell, taste and colour change this process is called as rancidity.
(ii) Storing food in airtight containers to slow the process Replacing oxygen in the containers with another gas such as nitrogen.
5.In decomposition reaction a compound splits up into two or more simpler substances. The reactions are carried out by applying heat, light or electricity. When a decomposition reaction is carried out with the help of electric current it is called electrolytic decomposition reaction.
EG; Thermal-Calcium carbonate (limestone) decomposes into calcium oxide and carbon dioxide when heated.
Electrolyte- Electrolysis of water
6. (a) {link at the below}
(b) 1) Helps to break down dietary protein into peptides and amino acids.
2) Acts on to break down dietary protein into peptides and amino acids.
3) Helps breaks down proteins into smaller amino acids.
4)It is responsible for the breakdown of fats that we consume.
7. (a)Herbivores have longer small intestine to allow the cellulose to be digested completely. Herbivores have longer intestine than carnivores to digest grass. The intestine would host many small bacteria that process and breakdown cellulose into glucose.
(b)Gastric glands in stomach release hydrochloric acid, enzyme pepsin and mucus. The mucus protects the inner lining of the stomach from the action of hydrochloric acid and enzyme pepsin. If mucus is not released, it will lead to erosion of inner lining of stomach, which may cause acidity and ulcer.
(c) Chlorophyll
(d)The liver has multiple functions, but its main function within the digestive system is to process the nutrients absorbed from the small intestine. Bile from the liver secreted into the small intestine also plays an important role in digesting fat.
8. A) Nutrition is the process by which an organism gains energy by digesting food materials.
It's necessary for human body as human body carries out various functions all the time even when the person is sleeping and most of the activities can not be carried out with energy and we gain energy from proteins, fats and carbohydrates that we obtain from the food we eat.
B)Peristalsis carries out the movements in the alimentary canal. Peristalsis is the involuntary constriction and relaxation of the muscles of the intestine or another canal, creating wave-like movements that push the contents of the canal forward.
C) The pancreas is an organ located in the abdomen. It plays an essential role in converting the food we eat into fuel for the body's cells. The pancreas has two main functions: an exocrine function that helps in digestion and an endocrine function that regulates blood sugar.