Mark ëTí if the statement is true and ëFí if it is false:
(a) Digestion of starch starts in the stomach. (T/F)
(b) The tongue helps in mixing food with saliva. (T/F)
(c) The gall bladder temporarily stores bile. (T/F)
(d) The ruminants bring back swallowed grass into their mouth and chew it for some time. (T/F)
a) False
Carbohydrate digestion begins in the buccal cavity with the mechanical action of chewing and this contains several enzymes salivary analyse and lysozyme. Then digestion of carbohydrates continues in the stomach then in the small intestine which contains pancreatic (helps in starch hydrolization) and intestinal juice.
b) True
Enzymes in the saliva begins to digest complex food materials that is partly digested by salivary amylase. With the help of the tongue, the bolus is moved into the oesophagus by swallowing the food’ smaller pieces. Saliva contains mucus that moistens the food and also cleans the tongue. It also contains immunoglobulins and lysozymes that contains antibacterial action.
c) True
The gall bladder stores and secretes the bile juice in the duodenum and is stored in it until the food material reaches the stomach. Gall bladder contains natural mechanism to contract at the same time when the food material reaches the stomach.
d) True
The ruminants brings back swallowed grass to their mouth and chew this for some time. Grass contains cellulose and is a carbohydrate which can only be digested by ruminants because they have rumen. When they eat grass, it sent to the rumen where enzymes are present that acts on it and moisten it. Then it is sent back to the mouth from where ruminants chew it for sometimes.
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:-
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:-
Sketch the cross section of soil and label the various layers.
- Q:-
Here is a crossword puzzle: Good luck!
Across
3. Liquid waste products
4. Solid waste extracted in sewage treatment
6. A word related to hygiene
8. Waste matter discharged from human bodyDown
1. Used water
2. A pipe carrying sewage
5. Micro-organisms which causes cholera
7. A chemical to disinfect water - Q:-
Take three test-tubes. Fill æth of each with water. Label them A, B and C. Keep a snail in test-tube A, a water plant in test-tube B and in C, keep snail and plant both. Which test-tube would have the highest concentration of CO2?
- Q:-
Sketch the reproductive parts of a flower.
- Q:-
Solve the following crossword puzzle with the clues given:
Across
2. Plantation prevents it.
5. Use should be banned to avoid soil pollution.
6. Type of soil used for making pottery.
7. Living organism in the soil.Down
1. In desert soil erosion occurs through.
3. Clay and loam are suitable for cereals like.
4. This type of soil can hold very little water.
5. Collective name for layers of soil. - Q:-
Describe how crystals of copper sulphate are prepared.
- Q:-
Match the items in Column I with those in Column II:
Column I Column II
(i) A home for living organisms (a) Large particles
(ii) Upper layer of the soil (b) All kinds of soil
(iii) Sandy soil (c) Dark in colour
(iv) Middle layer of the soil (d) Small particles and packed tight (v) Clayey soil (e) Lesser amount of humus - 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.
Recently Viewed Questions of Class 7 Science
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There are ten tubewells in a lane of fifty houses. What could be the long term impact on the water table?
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Sketch the cross section of soil and label the various layers.
- Q:-
The water holding capacity is the highest in
(i) sandy soil
(ii) clayey soil
(iii) loamy soil
(iv) mixture of sand and loam - Q:-
How would you show that setting of curd is a chemical change?
- Q:-
Why should oils and fats be not released in the drain? Explain.
- 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:-
Describe the function of the heart.
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Salma takes 15 minutes from her house to reach her school on a bicycle. If the bicycle has a speed of 2 m/s, calculate the distance between her house and the school.
- Q:-
Solve the following crossword puzzle with the clues given:
Across
2. Plantation prevents it.
5. Use should be banned to avoid soil pollution.
6. Type of soil used for making pottery.
7. Living organism in the soil.Down
1. In desert soil erosion occurs through.
3. Clay and loam are suitable for cereals like.
4. This type of soil can hold very little water.
5. Collective name for layers of soil. - Q:-
Look at Fig. 4.13. Mark where the heat is being transferred by conduction, by convection and by radiation.
- NCERT Chapter