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.
Write one similarity and one difference between the nutrition in amoeba and human beings.
Label Fig. 2.11 of the digestive system.
Can we survive only on raw, leafy vegetables/grass? Discuss.
Match the items of Column I with suitable items in Column II
Column I Column II
(a) Salivary gland (i) Bile juice secretion
(b) Stomach (ii) Storage of undigested food
(c) Liver (iii) Saliva secretion
(d) Rectum (iv) Acid release
(e) Small intestine (v) Digestion is completed
(f ) Large intestine (vi) Absorption of water
(vii) Release of faeces
Name the type of carbohydrate that can be digested by ruminants but not by humans. Give the reason also.
Why do we get instant energy from glucose?
Match the items of Column I with those given in Column II:
Column I Column II
Food components Product(s) of digestion
Carbohydrates Fatty acids and glycerol
Proteins Sugar
Fats Amino acids
Where is the bile produced? Which component of the food does it help to digest?
Tick (✓) mark the correct answer in each of the following:
(a) Fat is completely digested in the
(i) stomach (ii) mouth (iii) small intestine (iv) large intestine
(b) Water from the undigested food is absorbed mainly in the
(i) stomach (ii) foodpipe (iii) small intestine (iv) large intestine
What are villi? What is their location and function?
State similarities and differences between the laboratory thermometer and the clinical thermometer.
State differences between acids and bases.
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
Name the elements that determine the weather of a place.
Fill the missing word in the blank spaces in the following statements:
(a) Wind is——————air.
(b) Winds are generated due to —————— heating on the earth.
(c) Near the earth’s surface __________air rises up whereas ___________ air comes down.
(d) Air moves from a region of ——— pressure to a region of ———.
In addition to the rock particles, the soil contains
(i) air and water
(ii) water and plants
(iii) minerals, organic matter, air and water
(iv) water, air and plants
Why does an athlete breathe faster and deeper than usual after finishing the race?
Match structures given in Column I with functions given in Column II.
Column I Column II
(i) Stomata (a) Absorption of water
(ii) Xylem (b) Transpiration
(iii) Root hairs (c) Transport of food
(iv) Phloem (d) Transport of water
(e) Synthesis of carbohydrates
Fill in the blanks:
(a) Production of new individuals from the vegetative part of parent is called_____________.
(b) A flower may have either male or female reproductive parts. Such a flower is called_____________.
(c) The transfer of pollen grains from the anther to the stigma of the same or of another flower of the same kind is known as _____________.
(d) The fusion of male and female gametes is termed as _____________.
(e) Seed dispersal takes place by means of _____________, _____________ and _____________.
Classify the following as motion along a straight line, circular or oscillatory motion:
(i) Motion of your hands while running.
(ii) Motion of a horse pulling a cart on a straight road.
(iii) Motion of a child in a merry-go-round.
(iv) Motion of a child on a see-saw.
(v) Motion of the hammer of an electric bell.
(vi) Motion of a train on a straight bridge.
Tick the correct answer:
(a) In cockroaches, air enters the body through
(i) lungs (ii) gills
(iii) spiracles (iv) skin
(b) During heavy exercise, we get cramps in the legs due to the accumulation of
(i) carbon dioxide (ii) lactic acid
(iii) alcohol (iv) water
(c) Normal range of breathing rate per minute in an average adult person at rest is:
(i) 9ñ12 (ii) 15ñ18
(iii) 21ñ24 (iv) 30ñ33
(d) During exhalation, the ribs
(i) move outwards (ii) move downwards
(iii) move upwards (iv) do not move at all
Explain the factors responsible for the depletion of water table.
Look at Fig. 4.13. Mark where the heat is being transferred by conduction, by convection and by radiation.
Fill in the blanks:
(a) Cleaning of water is a process of removing ____________.
(b) Wastewater released by houses is called ____________.
(c) Dried ____________ is used as manure.
(d) Drains get blocked by ____________ and ____________.
Is the distilled water acidic/basic/neutral? How would you verify it?
Make a sketch showing groundwater and water table. Label it.
Explain how groundwater is recharged?
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 body
Down
1. Used water
2. A pipe carrying sewage
5. Micro-organisms which causes cholera
7. A chemical to disinfect water
State two experiences that made you think that air exerts pressure (other than those given in the text).
Explain why rusting of iron objects is faster in coastal areas than in deserts.