Which part of the digestive canal is involved in:
(i) absorption of food ________________.
(ii) chewing of food ________________.
(iii) killing of bacteria ________________.
(iv) complete digestion of food ________________.
(v) formation of faeces ________________.
i) Small Intestine
The digestion of fats starts in the stomach and completes or ends in the small intestine. Small intestine secretes bile, pancreatic juice and intestinal juice. They all contains fat digesting enzymes.
ii) Buccal Cavity (Mouth)
The entire process of digestion starts in our mouth, with churning. When we chew food, it gets broken down complex large pieces into smaller pieces which are easier to digest. When mixed with saliva which secretes salivary amylase, chewing process allows to extract the greatest possible amount of nutrients from the food we eat.
iii) Stomach
Antibiotics are present to kill the bacteria or antigens/ pathogens in our body, such as amoxicillin, clarithromycin (Biaxin), metronidazole (Flagyl), tetracycline (Sumycin), or tinidazole (Tindamax). Drugs which reduce the amount of acid in our stomach by blocking the tiny pumps that produce it.
iv) Small Intestine
Digestion of food completes in small intestine. The partially digested food is absorbed by the duodenum of the small intestine with the digestive juices from the liver, pancreas and its own walls.
v) Large Intestine
The large intestine consists of 75% water, fats and proteinaceous substance. Water from the undigested food is absorbed as the waste material. It takes several hours for food to travel and enters into the large intestine via the digestive tract. It occurs when fluid is in excess amount that is absorbed by the colon. As part of the digestion process, or due to fluid intake, food is mixed with large quantity of water. The colon absorbs the water and leaves the remaining materials as a semisolid mixture.
Popular Questions of Class 7 Science
- Q:-
Classify the changes involved in the following processes as physical or chemical changes:
(a) Photosynthesis
(b) Dissolving sugar in water
(c) Burning of coal
(d) Melting of wax
(e) Beating aluminium to make aluminium foil
(f ) Digestion of food - Q:-
Can we survive only on raw, leafy vegetables/grass? Discuss.
- Q:-
One litre of water at 30°C is mixed with one litre of water at 50°C. The temperature of the mixture will be
(a) 80°C (b) more than 50°C but less than 80°C
(c) 20°C (d) between 30°C and 50°C - Q:-
Stainless steel pans are usually provided with copper bottoms. The reason for this could be that
(a) copper bottom makes the pan more durable.
(b) such pans appear colourful.
(c) copper is a better conductor of heat than the stainless steel.
(d) copper is easier to clean than the stainless steel. - Q:-
When baking soda is mixed with lemon juice, bubbles are formed with the evolution of a gas. What type of change is it? Explain.
- Q:-
An iron ball at 40°C is dropped in a mug containing water at 40°C. The heat will
(a) flow from iron ball to water.
(b) not flow from iron ball to water or from water to iron ball.
(c) flow from water to iron ball.
(d) increase the temperature of both. - Q:-
Write one similarity and one difference between the nutrition in amoeba and human beings.
- Q:-
Given below is a crossword puzzle based on this lesson. Use hints to fill in the blank spaces with letters that complete the words.
Down Across
(D) 1 : Thorough washing (A) 1 : Keeps warm
2 : Animal fibre 2 : Its leaves are eaten by silkworms
3 : Long thread like structure 3 : Hatches from egg of moth
- Q:-
Make sketches of the two stages in the life history of the silk moth which are directly related to the production of silk.
- Q:-
A wooden spoon is dipped in a cup of ice cream. Its other end
(a) becomes cold by the process of conduction.
(b) becomes cold by the process of convection.
(c) becomes cold by the process of radiation.
(d) does not become cold.
Recently Viewed Questions of Class 7 Science
- Q:-
Can we survive only on raw, leafy vegetables/grass? Discuss.
- Q:-
Fill in the blanks in the following statements:
(a) When carbon dioxide is passed through lime water, it turns milky due to the formation of _________.
(b) The chemical name of baking soda is _________.
(c) Two methods by which rusting of iron can be prevented are _________ and _________.
(d) Changes in which only _________ properties of a substance change re called physical changes.
(e) Changes in which new substances are formed are called _________ changes. - Q:-
Explain how animals dwelling in the forest help it grow and regenerate.
- Q:-
A wooden spoon is dipped in a cup of ice cream. Its other end
(a) becomes cold by the process of conduction.
(b) becomes cold by the process of convection.
(c) becomes cold by the process of radiation.
(d) does not become cold. - Q:-
How would you show that setting of curd is a chemical change?
- Q:-
Which one of the following place is unlikely to be affected by a cyclone.
(i) Chennai (ii) Mangaluru (Mangalore) (iii) Amritsar (iv) Puri
- Q:-
Classify the changes involved in the following processes as physical or chemical changes:
(a) Photosynthesis
(b) Dissolving sugar in water
(c) Burning of coal
(d) Melting of wax
(e) Beating aluminium to make aluminium foil
(f ) Digestion of food - Q:-
Match the following :
(i) Land breeze blows during (a) summer
(ii) Sea breeze blows during (b) winter
(iii) Dark coloured clothes are preferred during (c) day
(iv) Light coloured clothes are preferred during (d) night - Q:-
When baking soda is mixed with lemon juice, bubbles are formed with the evolution of a gas. What type of change is it? Explain.
- Q:-
What are decomposers? Name any two of them. What do they do in the forest?
- NCERT Chapter