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 ____________ .
a) ingestion, digestion, absorption, assimilation, egestion
These are the basic steps of holozoic nutrition.
1. Ingestion: Ingestion involves the consumption of food by an organism. Animals are variously adapted for ingestion of food of specific types, that intakes through the mouth into the gastrointestinal tract (GI); by eating or drinking processes. In single-celled organisms ingestion takes place by absorbing a substance through the cell membrane or through the surface of the skin.
2. Digestion: Digestion involves the breakdown of large complex organic food molecules (carbohydrates, proteins, lipids, nucleic acid etc.) into the simpler, smaller or soluble molecules so that they can be absorbed into the watery blood plasma. In certain organisms, these smaller substance are absorbed by the small intestine into the blood stream.
3. Absorption: Absorption involves passing of digested food components through the wall of small intestine into the blood of lymph. These absorbed food molecules circulated to different cells of the body where they are being absorbed.
4. Assimilation: Assimilation involves the movement of digested food molecules into the different cells of the body where they are used. For example: glucose is used in respiration to provide energy to do the processes; and amino acids are used to build new proteins.
5. Egestion: Egestion involves the removal or elimination of undigested food materials from the alimentary canal as faeces.
On reaching the end of the small intestine the digested food products with the minerals and vitamins that are useful to the body, this should have been removed from the watery contents. These materials are then passed on to the large intestine for the forward processes.
(b) liver
Liver is the largest gland which is located in the upper right side of the abdominal cavity. The liver consists of two lobes: the right and the left lobe. The liver is an essential organ weighing body 1.6 kg that has many functions in the body, including making proteins and blood clotting, making of triglycerides and cholesterol, synthesis of glycogen and bile production.
(c) pepsinogen, prorennin etc.
Contraction and the expansion of muscles of the wall of the stomach brings about churning movement which helps in the mixing of food with the gastric juices which is a mixture of HCL, pepsinogen, prorennin, lipase and mucus etc.
(d) villi
Villi are small finger-like numerous microscopic projections found inside the inner walls of the small intestine. Villi absorb nutrients from the food we eat and then shuttle those nutrients into your bloodstream so that they can travel where they’re needed.
(e) food vacuole
A vacuole is a membrane-bound organelle and are kind of vesicle. Vacuoles are closed sacs, made of membranes with inorganic or organic molecules inside such as enzymes. They have irregular shape or size like the cell can change them as needed. They are present in eukaryotic cells and do many things.
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.
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 ________________.
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.
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
Why do we get instant energy from glucose?
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
Where is the bile produced? Which component of the food does it help to digest?
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.
How would you show that setting of curd is a chemical change?
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
Give one use each of a concave and a convex mirror.
Why do we often sneeze when we inhale a lot of dust-laden air?
Match the items in Column I with those in Column II:
Column I Column II
(a) Yeast (i) Earthworm
(b) Diaphragm (ii) Gills
(c) Skin (iii) Alcohol
(d) Leaves (iv) Chest cavity
(e) Fish (v) Stomata
(f) Frog (vi) Lungs and skin
(vii) Tracheae
Explain why there is no waste in a forest.
A carnivore with stripes on its body moves very fast while catching its prey. It is likely to be found in
(i) polar regions (ii) deserts
(iii) oceans (iv) tropical rainforests
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.
Match the items given in Column I with those in Column II:
Column I Column II
Chlorophyll Bacteria
Nitrogen Heterotrophs
Amarbel Pitcher plant
Animals Leaf
Insects Parasite
Mark ëTí if the statement is true and ëFí if it is false:
(i) During heavy exercise the breathing rate of a person slows down. (T/F)
(ii) Plants carry out photosynthesis only during the day and respiration only at night. (T/F)
(iii) Frogs breathe through their skins as well as their lungs. (T/F)
(iv) The fishes have lungs for respiration. (T/F)
(v) The size of the chest cavity increases during inhalation. (T/F)