Topic: Life Processes
CLASS 10 NOTES
TERM 1
Topic: Life processes
Q1. Define the following terms:
1) nutrition
2) photosynthesis
3) peristalsis
4) excretion
5) osmoregulation
6) holozoic nutrition
Ans. 1) 1 Nutrition-It is the mode of taking food by an organism and its utilization by
the body.
2)Photosynthesis-It is the process by which green plants can prepare their own
food in the presence of sunlight,carbondioxide,water,minerals and chlorophyll.
3)peristalsis:-it is a wave of contraction and expansion that takes place in the
Alimentary canal. It pushes the food forward.
4)excretion:-the process of elimination of metabolic waste from the body.
5) osmoregulation :-regulating the amount of water and salts in the body.
6)holozoic nutrition:-it is the mode of heterotrophic nutrition that involves
The intake of solid food.
Q2.Distinguish between:
1) breathing and respiration
Breathing respiration
It's a physical process It's a biochemical process
It consumes energy It releases energy
Its taking in fresh air and giving out foul air It's the oxidation of respiratory substrate
2) parasite and saprophyte
Parasite
Obtains nutrition from a living organism
called host
Possess sucking organs
3) aerobic and anaerobic respiration
Aerobic
It requires oxygen
Releases 38 ATP molecules
Saprophyte
Obtains nutrition from organic remains
They are absent
Anaerobic respiration
It doesn't require oxygen
Releases only 2 ATP molecules
Food is completely broken down
4) inhalation and exhalation
Inhalation
Taking in fresh air
Diaphragm becomes flat
Air pressure decreases in the lungs
5) ingestion and egestion
Ingestion
It's the process of taking in food
Involves catching,holding and putting food
'in the body
6) plant and animal respiration
Plant respiration
Rate of respiration is slow
Breathing is absent
Respiratory surface absent
Food is incompletely broken down
Exhalation
Giving out foul air
Diaphragm becomes dome shaped
Air pressure increases in the lungs
Egestion
It's the process of throwing out faecal
matter out of the body
Involves piling up of faecal matter and its
elimination thru anus.
Animal respiration
Rate of respiration is fast
Present
present
Q3. How do plants get rid of their waste products?
Ans. Plants get rid of their waste products by:
1) waste products are stored in old leaves that soon fall off.
2) Bark consists of dead cells which is peeled off periodically.
3) Some waste substances are excreted by roots.
4) Resins, gums , tannins etc are stored in old xylem.
Q4. How does amoeba dispose off its waste products?
Ans. amoeba lacks excretory organs. Waste products like ammonia and CO2 are passed
outside through the process of diffusion. Contractile vacuole also plays an important role in
the process of excretion.
Q5. Describe the mechanism of urine formation in humans.
Ans. its completed in 4 steps:
a) glomerular filtration: blood flows under pressure inside the glomerulus . as a result, it
undergoes ultrafiltration. Urea, uric acid, amino acids, hormones, glucose, ions and
water are filtered out and enter the Bowmans capsule.
b) Reabsorption:the filtrate passes thru proximal convoluted tubule. The capillaries
absorb all the useful components like: glucose, amino acids, ions etc.
c) Tubular secretion: it occurs in distal convoluted tubule. It is the active secretion of
waste by the blood capillaries into the urinary tubule. It ensures the removal of all the
waste from the blood.
d) Concentration of urine: 75% of water is reabsorbed in proximal convoluted
tubule.some 10% of water reabsorbed in henles loop.
e) Ureters : these are the narrow muscular tubesthat carry urine from kidneys to urinary
bladder.
f) Urinary bladder: it is a pear shaped sac that stores urine.
g) Utrethra: it is a tube that takes urine from bladder to outside.
Q6. Why is trachea lined with the rings of cartilage?
Ans. Trachea is lined with the rings of cartilage to prevent it from collapsing.
Q7. Identify the respiratory organ in :
a)leech b) cockroach c) crab d)mussel e)tadpole
Ans. a) skin b) trachea/ spiracles c) gills d) gills e) gills
Q8. How do plants exchange gases?
Ans. Plants exchange gases by the process of diffusion. Stomata help in the exchange of
gases. CO2 gas is taken in and O2 is released by the process of photosynthesis.
Q9. What is the role of HCL in the stomach.
Ans. it has two roles:
1) kills the microbes that enter along with food.
2) Creates an acidic medium for pepsin functioning.
Q10. Name the raw materials of photosynthesis .
Ans. 4 requirements of photosynthesis are-
1 carbondioxide -is taken through stomata.
2 water and minerals- are transported to the leaves by the vessels.
3 chlorophyll-is present in the leaves of the plants.
4 sunlight-is absorbed by the chlorophyll present in the leaves.
Q11. Identify the specific mode of nutrition in :
a) cuscuta b) ascaris c) mushroom d) deer e) humans Ans. a) parasitic b) parasitic c) saprophytic d)and e) holozoic
Q12. What is fermentation? What is its use?
Ans. fermentation is the kind of anaerobic respiration carried out by a unicellular organism
called yeast. Yeast converts a sugar solution into alcohol and also releases CO2
Gas during this process. Its used in bakery and brewery industries.
Q13. Mention the raw materials needed for photosynthesis.
Ans. 4 requirements of photosynthesis are- 1 carbondioxide -is taken through stomatas
2 water and minerals- are transported to the leaves by the vessels.
3 chlorophyll-is present in the leaves of the plants.
4 sunlight-is absorbed by the chlorophyll present in the leaves.
Q14. Draw a well labeled diagram of human respiratory system.
Ans.
Q15. Draw a well labeled diagram of human excretory system. Ans.
Q16. Draw a well labeled diagram of cross section of a leaf.
Q17. Draw a dig. Of stomata and write its 2 functions
Ans. functions:a) exchange of gases
b) loss of extra water by transpiration
Q18. Draw a well labeled diagram of human digestive system
Q19. Name the 5 steps of holozoic nutrition
Ans. 1) ingestion:-- the process of intake of food.
3) digestion:-- changing complex food substances to simple form by the action of enzymes.
4) Absorption:-- digested food is absorbed in blood.
5) Assilmilation:-- the absorbed food components are converted into components of cytoplasm. 6) Egestion :-throwing out of waste.
Q20. Name the secretions and their role in digestion for the following glands:: Ans.
Gland
Salivary( mouth)
Gastric( stomach)
Pancreas(abdomen)
Liver( abdomen)
Secretion
Saliva( salivary amylase)
Mucus, HCL, Pepsin
Pancreatic juice
Bile
Function
Digests carbohydrate( starch)
Mucus has protective function
HCL kills the microbes
Pepsin digests proteins.
Trypsin digests proteins
Amylase digests carbohydrate
Lipase digests lipids and fats.
Emulsification of fats
Q21 . why do aquatic organisms show a higher breathing rate?
Ans. this is bcos, water has low O2 content than the content of O2 in air.
Q22. why do we feel muscle cramps after heavy exercise?
Ans. this is bcos our cells and tissues become O2 deficient and start undergoing anaerobic
respiration. This produces lactic acid and we feel muscle cramps.
Q23. Why is it advised to breathe thru nose?
Ans. The mucus and hair present in the nasal cavity help to filter the inhaled air.
Q24.What is a diaphragm?
Ans. it's a muscular partition between thorax and abdomen,it can bcum flat or dome shaped due to contraction and relaxation of muscles.
Q25. What is the other name of larynx? Ans. it is also called adam's apple