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
Fill in the blanks:
(a) The main steps of nutrition in humans are __________, __________, __________, _________ and __________.
(b) The largest gland in the human body is __________.
(c) The stomach releases hydrochloric acid and ___________ juices which act on food.
(d) The inner wall of the small intestine has many finger-like outgrowths called _________.
(e) Amoeba digests its food in the ____________ .
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.
Which features adapt polar bears to live in extremely cold climate?
(i) A white fur, fat below skin, keen sense of smell.
(ii) Thin skin, large eyes, a white fur.
(iii) A long tail, strong claws, white large paws.
(iv) White body, paws for swimming, gills for respiration.
Give two examples each of conductors and insulators of heat.
What planning is required in advance to deal with the situation created by a cyclone?
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
Fill in the blanks:
(i) The average weather taken over a long time is called ___________. (ii) A place receives very little rainfall and the temperature is high throughout the year, the climate of that place will be ___________ and ___________ .
(iii) The two regions of the earth with extreme climatic conditions are ___________ and __________.
In the circuit shown in Fig. 14.25
(i) Would any of the bulb glow when the switch is in the ‘OFF’ position?
(ii) What will be the order in which the bulbs A, B and C will glow when the switch is moved to the ‘ON’ position?
What will happen if there are no platelets in the blood?
Distinguish between a parasite and a saprotroph.
Three liquids are given to you. One is hydrochloric acid, another is sodium hydroxide and third is a sugar solution. How will you identify them? You have only turmeric indicator.
The tropical rainforest has a large population of animals. Explain why it is so.