Saturday 25 April 2015

LIFE PROCESSES IMPORTANT QUESTON ANSWERS

 
 
 
 
1 MARKS QUESTIONS 
1. A farmer floods his field everyday thinking that watering in this manner will result a better yield of his wheat crop. What will be the result of this action of the farmer. 
Ans.This will result in water logging of the soil due to which roots cannot breathe and ultimately plants will die .
2. Name the term for transport of food from leaves to other parts of plants.
Ans.Translocation
3. Which pancreatic enzyme is effective in digesting proteins? 
Ans.Trypsin
4. Which enzyme is present in saliva breaks down starch? 
Ans.Salivary amylase.
5. After a vigorous exercise you may experience cramps in your leg muscles. Why does this happen? 
Ans.Accumulation of lactic acid
6. Name the organelle in which photosynthesis occurs. 
Ans.Chloroplast.
7. Name the type of blood vessels which carry blood from organs to the heart. 
Ans.Veins.

8. Name the respiratory structures of i.Mosquito ii)earth worm.

Ans.i) mosquito—System of air tubes. ii)earth worm—moist skin.
9. Write the two functions of kidneys. 
Ans. Osmoregulation and excretion.

10. What are spiracles.

Ans The holes found on the lateral side of insect‘s body.

2 MARKS QUESTIONS 
1. Differentiate autotrophs and heterotrophs.
Ans.The organism which prepare their own food are called autotrophs for eg: green plants .

 The organisms which depend on the food prepared by other organisms are called heterotrophs for eg: animals
2.Differentiate between aerobic respiration and anaerobic respiratrion. 
Ans.   Aerobic respiration                                            
1. It occurs in the presence of oxygen              .

2. Glucose is completely broken down to carbondioxide and water.

3. More energy is released 38 ATP. 
Anaerobic respiration
1 .It occurs in the absence of oxygen
2. Glucose is incompletely oxidised to ethanol or lactic acid
3. Less energy is produced 2ATP
3. Explain the role of the following in the process of digestion in the human body
A) saliva

B) trypsin

a) saliva-

a) Saliva contains an enzyme salivary amylase which digests starch

b) trypsin.-helps in digestion of proteins.
4. What is double circulation.? 
Ans..In double circulation blood goes through the heart twice during each cycle in vertebrates.

5 Write any two points of difference between respiration in plants and respiration in animals.

Respiration in plants.



1.In plants separate respiratory organs are absent
2.The rate of respiration is slow.
3.They lack respiratory surface 
Respiration in animals 
1.In animals respiratory organs are generally present 
2.The rate of respiration is fast.

3. Respiratory surface is generally present. 

6. Differentiate Holozoic nutrition and saprophytic nutrition.

Holozoic nutrition
In this nutrition organisms derive their food by consuming complex organic materials by the process of ingestion and then converting the complex  molecules into simpler ones to  obtain nutrients. Eg. animals and human beings. 
Saprophytic nutrition
In this type of nutrition organism derive their food from the dead and decaying materials. Eg.fungi
7. Why do veins have thin walls compared to arteries?
Ans: Veins do not have thick walls because blood is no longer under pressure but blood emerges from the heart under high pressure. So arteries have thick walls
8. Where do the plants get each of the raw materials? 
(a) CO2                  (b) water                            (c) minerals

Ans.
(a) CO2- from air,                 (b)water-from soil      (c)minerals-from soil along with water.

9. What do the following transport?

 a)xylem and  phloem   c)pulmonary vein        d) venacava

Ans.

a) xylem-water and minerals

b) phloem- prepared food.

c) Pulmonary vein-oxygenated blood

d) vena cava -deoxygenated blood
10. Write one function each of the following components of transport system in human beings. a)arteries  b) veins c)capillaries 
ans:

a) arteries- carry blood from heart to different parts of body

 b) veins-carry blood from different parts of body to the heart.

c) Capillaries-exchange of material between blood and surrounding cells.
11. a) How is fat digested in our body? b) Where does this take place? 
Ans.

A) fats are emulsified by bile salts. The emulsified fats are acted upon by pancreatic and intestinal lipase to form fatty acids and glycerol.

b) digestion of fats occurs in small intestine.

3 MARKS QUESTIONS


 1. What is the function of epiglottis in man? Draw a labeled diagram showing the human respiratory system. 
Epiglottis. It is an adjustable flap of fibro cartilage that covers glottis when food is being swallowed.  Diagram of human reaspiratory system. Fig 6.9 (NCERT text book page no.104.)

3. What is known as double circulation Briefly explain the process .

Ans.It is passage of the same blood twice through the heart first on the right side, then on the left side in order to complete one cycle. It has two components ,pulmonary circulation and systemic circulation. Hint. pulmonary circulation and systemic circulation 4.How water is transported upwards in plants? Hint. Transpiration pull
5. Name the tissue that transports the prepared food in plants . Explain the mechanism of transport of food in plants. 
Ans.: phloem  Hint: translocation using energy from ATP. 6Briefly describe the excretory system in human beings. Hint a pair of kidneys a pair of ureters,a urinary bladder and a urethra.

7.Describe the functioning of nephrons.

 Hint: filteration, reabsorbtion, secretion
8.What are the differences between the transport of materials in xylem and phloem hint transport in xylem:
water transport using transpirational pull Transport in phloem: food, transport using energy from ATP
9. Draw and label the sectional view of the human heart.
Diagram NCERT text book fig 6.10 page 106
10. dfifferentiate between osmoregulation and excretion excretion is the elimination of metabolic waste products from the body. 
Osmoregulation is regulating osmotic pressure of the body fluids by controlling the amount of water and salts in the body

5 MARKS QUESTIONS 

1. Write the process of digestion.

Digestion in mouth,stomach, duodenum,digestion in jejunum . Digestion of carbohydrates, digestion of proteins, digestion of fats

2.Which chamber of human heart receives oxygenated blood? Explain how oxygenated blood from this chamber is sent to all parts of the body.

Ans Left atrium

 Hint. Explanation of systemic circulation

3.Draw the diagram of cross section of a leaf and label the following in it. 
A) Chloroplast b)guard cell c)lower epidermis d)upper epidermis 
Name the two stages in photosynthesis. 
Ans Draw fig 6.1 NCERT text book page 96 Two stages light reaction and dark reaction

4.Draw a neat diagram of the human respiratory system and label the parts.

 b)How are the alveoli designed to maximize the exchange of gases. Suggest any two features.

Draw fig6.9 and explain the structure and function of alveoli
5.a) Draw a diagram of human alimentary canal.
 b) label the following on the diagram Esophagus, liver gall bladder, duodenum
c)What is the function of liver in human body 

ans. : Draw fig 6.6 in page 99 of NCERT and label the parts mentioned. Liver. Secretes bile that emulsifies fats . Bile provide alkaline medium for digestion of proteins.
 
 
 
v  Life processes – The processes that are necessary for an organism to stay alive. Eg. Nutrition, respiration, etc.
v  Criteria of life- (i) Growth  (ii) Movement
v  Nutrition- The process in which an organism takes in food, utilizes it to get energy, for growth, repair and maintenance, etc. and excretes the waste materials from the body.
v  Types of nutrition                                                                           
1.      Autotrophic nutrition(Auto =self:  trophos = nourishment) E.g. Plants, Algae, blue green bacteria.
o   Process – Photosynthesis(Photo=light; Synthesis= to combine)
o   Raw materials- (i) Carbon dioxide (ii)Water
o   Equation-                  sunlight                                                                         
o    6CO2  +  6H2O                          C6H12O6      +     6O2
                                     Chlorophyll
o   Energy conversion- Light/Solar energy to Chemical energy
o   Role off Chlorophyll- To trap the sun’s energy for photosynthesis
o   Factors- (i) Carbon dioxide (ii) Water(iii)  Light (iv)  Temperature
o   Events/ Steps of photosynthesis-    
(i)       Absorption of light energy by chlorophyll
(ii)      Conversion of light energy to chemical energy & Splitting of water molecule into Hydrogen & oxygen
(iii)   Reduction of Carbon dioxide to Carbohydrate
o   Gaseous exchange- (i) Gas used- Carbon dioxide 
                                     (ii)  By product - Oxygen
o   Source of raw materials-
(i)         Carbon dioxide –Land plants- Air, Aquatic plants- Water
(ii)      Water & Minerals - Soil

2.      Heterotrophic nutrition (Hetero =others:  trophos = nourishment) Eg. Animals, plants lacking chlorophyll like fungi.
(a)    Saprophytic nutrition: Organisms feeds on dead decaying plants or animals material. E.g. Fungi, Bacteria

(b) Parasitic nutrition: Organisms obtain food from the body of another living (host)
o   Endoparasite : Parasite lives inside the body of the host e.g. tapeworm, roundworm.
o   Exoparasite:  Parasite lives on the body of the host. E.g. lice, leech.
 Note- The parasite benefits while the host is usually harmed e.g. Cuscutta-plant parasite (amar bel), plasmodium (malarial parasite).

 (c) Holozoic nutrition: Organism (mostly animals) take in whole food and then digest it into smaller particles with enzyme. Eg. Amoeba, Paramoecium. Animals, human beings.
o   Steps in Holozoic nutrition
(i)                 Ingestion: taking in of food.
(ii)               Digestion: breaking down of complex food into simpler, absorbable form.
(iii)             Assimilation: Utilization of digested food from the body.
(iv)             Egestion: Removing undigested food from the body          


o   Nutrition in human beings
§  Alimentary canal-  
           Mouth → Oesophagus → Stomach → Small intestine  → Large intestine
§  Important gland/juices
         (Refer to figure 6.6 page no.97 of N.C.E.R.T  Text book)

Organ
Gland
Enzyme/Juice
Function

Mouth
Salivary glands
Salivary Amylase
Converts starch into sugar
Stomach
Gastric glands
Gastric juice-
(i) Hydrochloric
     acid                →


(ii)  Pepsin         →
(iii) Mucus        →

(a) Kills harmful bacteria that
     enters with the food.
(b)   Makes the medium alkaline
      for the action of Pepsin
Digests proteins
Protects the inner lining of the stomach from the corrosive action of Hydrochloric acid.         
Small intestine
1) Liver






2)   Pancreas  
(i) Bile juice      →






(ii)  Pancreatic
      Juice        
  • Amylase →
  • Trypsin   →
  • Lipase     →



(a) Makes the medium acidic
      for the action of Pancreatic
     enzymes.
(b) Breaks down large fat
     molecules into smaller globules
     so that enzymes can act upon
     them.


Converts Carbohydrates to glucose
Converts Proteins to Amino acids
Converts Fats into Fatty acids & Glycerol

§  Peristaltic movements- Rhythmic contraction of muscles of the lining of Alimentary canal to push the food forward.
§  Sphincter muscle- Helps in the exit of food from the stomach.

§  Villi- Small finger like projections on the walls of-
(v)               Small intestine- To increase the surface area for the absorption of food.
(vi)             Large intestine- For absorption of water.


v  Respiration- The process by which digested food is broken down with the help of Oxygen to release energy.

o   Types of  respiration- (i) Aerobic respiration  (ii)Anaerobic respiration 

Aerobic respiration

Anaerobic respiration 
1.  Takes place in presence of Oxygen.

2.  End products- Carbon dioxide & Water

3. More energy is released.

4.  Takes place in Cytoplasm & Mitochondria

5. Complete oxidation of glucose takes place.

6. It occurs in most organisms.





7.  Equation-
Glucose→ Pyruvate→ CO2  +  H2O + Energy
1.  Takes place in absence of Oxygen.

2. End products- Ethanol & Carbon dioxide

3. Less energy is released.

4.  Takes place in only in Cytoplasm.

5. Incomplete oxidation of glucose takes place.

6.  It occurs in certain bacteria, yeast & certain tissues of higher organisms. E.g. In humans during vigorous exercise, when the demand for Oxygen is more than the supply, muscle cells respire anaerobically for some time.

7.  Equation-
In Yeast-
Glucose→ Pyruvate→ Ethanol + H2O + Energy
In muscle cells -
Glucose→ Pyruvate→ Lactic acid + Energy

  • Some common features of Respiratory organs-                                                                            (i) Large surface area- for greater rate of diffusion of respiratory gases.                                   (ii)  Thin permeable walls – to ensure easy diffusion & exchange of gases.                              (iii)  Extensive blood supply- Respiratory organs are richly supplied with blood vessels for quick transport of gases.
  • Gaseous exchange in plants-  
    • Process – Diffusion
    • Direction of diffusion depends on- (i) Environmental conditions
                                                              (ii)  Requirement of the plant.
§  Day time- Carbon dioxide given out during respiration is used for photosynthesis. Therefore only Oxygen is released, which is a major activity during the day.
§  Night time – Only respiration takes place. Therefore only Carbon dioxide is released, which is a major activity during the night.

  •  Gaseous exchange in animals-      
§  Terrestrial animals- take Oxygen from the atmosphere.
§  Aquatic animals- take Oxygen dissolved in water. (Oxygen content is low in water, therefore they breathe faster.
  • Human Respiratory system-                                                                                                External nostrils → Nasal cavity → Trachea→ Bronchi → Bronchioles →Alveoli
§  Rings of cartilage present in the throat ensure that the trachea (air passage) does not collapse when there is less air in it.
§  Lungs – (i) Present in the thoracic cavity.                                                           
                    (ii)  They are spongy, elastic bags consisting of Bronchi,
                                             Bronchioles and Alveoli
                               Refer to figure 6.9 page no. 104 of N.C.E.R.T  Text book)
  • Respiration occurs in two phases-
  • (i) External-Breathing, which is a mechanical process.                                                               (ii) Internal - Cellular respiration
  • Mechanism of breathing – It includes : (i)Inhalation   (ii) Exhalation
  • Exchange of gases-
§  Unicellular organisms- By Diffusion
§  Animals- (i) As the body size is large, diffusion alone is not enough.
                      (ii)  Respiratory pigments also required.
                      (iii) Respiratory pigment in human beings is Haemoglobin,
                             which is present in red blood corpuscles.
                       (iv) It has very high affinity for Oxygen.
                       (iv) Carbon dioxide is more soluble in water thanOxygen, so it
                               Gets dissolves in blood and is thus transported.
v  Transportation
  • Transportation in human beings-
§  Blood- (i) It is a fluid connective tissue.
    (ii) Components- (1) Fluid medium- Plasma
                                                         (2)  Red blood corpuscles
                                                         (3)  White blood corpuscles
                                                         (4)  Platelets suspended in plasma
                             (iii)  Plasma transports food, Oxygen, Carbon dioxide,
                                                  Nitrogenous wastes, etc.
§  Functions of blood- (i) Transport of respiratory gases.
                         (ii) Transport of nutrients.
                         (iii) Transport of waste products.
                         (iv)  Defence against infection
§  Blood vessels- (i) Arteries (ii) Veins (iii) Capillaries
                          Arteries
                        Veins
1.  Thick walled.
2.  Deep seated.
3.  Carry blood away from the heart.
4.  Carry Oxygenated blood.
5.  Valves absent.
1.  Thin walled.
2.  Superficial. 
3.  Carry blood to the heart.
4. Carry Deoxygenated blood.
5.  Valves present

§  Heart-    (Refer to figure 6.10 page no. 106 of N.C.E.R.T  Text book)
      (i) It is a muscular organ, which works as a pump in the circulatory system.
                       (ii)  It is the size of our fist.
                       (iii)  It has two sides, which are separated by a partition so that the oxygenated and
                              deoxygenated blood do not get mixed up.
                       (iv) It has four chambers-
        Two upper chambers called Atria. 
        Two lower chambers called Ventricles.    
§  Working of heart-
Left side- (i)  Left atrium relaxes & the Oxygenated blood enters it from
                                               the lungs through the pulmonary vein.
  (ii)  Left atrium contracts & the blood enters the left ventricle
         through the valve.
  (iii) Left Ventricle contracts and the blood is pumped into the
           largest artery ‘Aorta’ and is carried to all parts of the body.
Right side- (i) Right atrium relaxes & the deoxygenated blood from the body enters it 
                                          through superior and inferior Vena cava.
      (ii)  Right atrium contracts & the blood enters the right Ventricle through
            the valve.
                                             (iii) Right Ventricle contracts and the blood is pumped into the Pulmonary
                                                    artery and is carried to lungs.
§  Valves- Unidirectional to prevent the backward flow of blood.
§  Pulmonary vein is the only vein that carries Oxygenated blood.
§  Aorta is the only artery that carries Deoxygenated blood.
§  Double circulation in man- because the blood passes through the heart twice in one complete cycle of the circulation.
§  Capillaries- (i) Form the connection between arteries & veins.
                                           (ii) Walls are one cell thick only for easy exchange of
                                                  blood.
§  Platelets- Plug the leaks of arteries and veins by clotting the blood.
§  Lymph- Extracellular fluid similar to plasma but colourless with lesser protein.
§  Function of lymph-  (i) Transportation of digested & absorbed fats from
                                            the small intestine.
                                       (ii)  Drains excess fluid from the intercellular spaces
                                              back in the blood.
§  Higher animals-  E.g., birds, mammals.                                                       
(i)                  Oxygenated blood & Deoxygenated blood are completely separate for efficient Oxygen supply.  
(ii)               This is  to fulfil higher energy needs and to maintain body temperature (warm blooded animals). 
§  Amphibians & reptiles- have 3 chambered heat where little mixing of  Oxygenated blood & Deoxygenated blood takes place. Therefore their body temperature varies with the temperature of the environment. (cold blooded animals)                                                                          
  • Transportation in plants-
§  Plants need less energy needs- because they do not move and therefore have a slow transport system
§  Transport of water- 
(i)                 Takes place by xylem tissue present in roots, stem, leaves and is therefore interconnected.
(ii)               Root cells take up ions from the soil, which creates a concentration difference between root and soil. Column of water therefore rises upwards.
§  In very tall plants- transpiration creates a suction pressure, which pulls the water upwards.
§  Importance of transpiration-
(i)                 Helps in upward movement of water in plants.
(ii)               It regulates the temperature in plants.   
                 §  Transport of food-
(i)                 Takes place by phloem tissue.
(ii)               Movement of prepared food in plants is called translocation.   
v  Excretion- The biological process of removal of harmful metabolic wastes in living organisms.
v  Excretion in human beings-
(Refer to figure 6.13 page no. 110 of N.C.E.R.T  Text book)
§  Organs of excretory system- (i) Kidneys        (iii) Urinary bladder
                                                    (ii) Ureters         (iv) Urethra
§  Kidneys-
(i)                 Two in number
(ii)               Bean shaped      
(iii)             Present in abdomen on either side of the backbone
(iv)             Basic unit is nephron.
a.       Glomerulus- Group of capillaries (cluster) present in Bowman’s                            capsule to receive blood from renal artery and filters it.
b.      Bowman’s capsule- Cup shaped structure, which contains glomerulus.
c.        Convoluted tubule-is long and reabsorbs vital nutrients like glucose, amino acids, salts, urea and water.

      Note-Vital functions of kidneys- (a) Filtration & removal of Nitrogenous wastes                                                                  
                                          (b)  Reabsorption of vital nutrients
§  Ureters- Transport the urine formed in the kidneys to the urinary bladder.
§  Urinary bladder- Muscular bag like structure to store urine.
§  Urethra- Helps in removal of urine when the Urinary bladder is full.
§  Artificial kidney- Principle: Dialysis
v  Excretion in plants-   
    • Gaseous wastes- CO2 in respiration & O2 in photosynthesis are removed by the process of diffusion.
    • Excess water- is removed by transpiration.
    • Other wastes- (i) Stored in cellular vacuoles or in leaves, which fall off or as gums, resins, etc. in old xylem.
                             (ii)  Excreted in soil.
v  Important diagrams-
1.      Open & close stomata
2.      Steps of nutrition in Amoeba
3.      Alimentary canal of human beings/ Digestive system of human beings
4.      Respiratory system of human beings
5.      Structure of heart.
6.      Excretory system of human beings
7.      Structure of nephron
 
 
 

No comments:

Post a Comment