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.
3. Which pancreatic enzyme is effective in digesting proteins?
4. Which enzyme is present in saliva breaks down starch?
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.
7. Name the type of blood vessels which carry blood from organs to the heart.
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 answer
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.
It occurs in the presence of oxygen
Glucose is completely broken down to carbon dioxide and water.
More energy is released 38 ATP.
It occurs in the absence of oxygen.
Glucose is incompletely oxidised to ethanol or lactic acid
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 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.
- In plants separate respiratory organs are absent
- The rate of respiration is slow.
- They lack respiratory surface
Respiration in animals
- In animals respiratory organs are generally present
- The rate of respiration is fast.
- Respiratory surface is generally present.
6 Differentiate Holozoic nutrition and saprophytic 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.
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
a) CO2 from air,
c)minerals-from soil along with water.
9. What do the following transport?
a)xylem b phloem c) pulmonary vein d) venacava
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
(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?
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?
Answer: Transpiration in leaves creates pull force and osmosis creates push fore. These two forces together helps in the movement of water and minerals dissolved the leaves.
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.
Ans: Functioning of Nephron
(i). Filtration: Filtration of blood takes place in Bowman’s capsule from the capillaries of glomerulus. The filtrate passes into the tubular part of the nephron. This filtrate contains glucose, amino acids, urea, uric acid, salts and a major amount of water.
(ii) Re-absorption: As the filtrate flows along the tubule useful substances such as glucose, amino acids, salts and water are selectively re-absorbed into the blood by capillaries surrounding the nephron tubule. The amount of water re-absorbed depends on the need of the body and also on the amount of wastes to be excreted.
(iii) Urine: The filtrate which remains after re-absorption is called urine. Urine contains dissolved nitrogenous waste, i.e. urea and uric acid, excess salts and water.
Urine is collected from nephrons by the collecting duct to carry it to the ureter.
8.What are the differences between the transport of materials in xylem and phloem hint transport in xylem:
Ans: water transport using transpirational pull Transport in phloem: food, transport using energy from ATP
9. Lymph is another type of fluid involved in transportation. Justify the statement by two reason.
1. It drains tissue fluid from the extra cellular space back into blood.
2. it takes lymphocytes and antibodies from the lymph nodes to the blood.
3. Some of the fluid from digestive tract is absorbed in the lymph and store the fluid Temporarily.
10. differentiate between osmoregulation and excretion excretion is the elimination of metabolic waste products from the body.
Ans: Osmoregulation is regulating osmotic pressure of the body fluids by controlling the amount of water and salts in the body
11. What is the function of liver in human body
ans. : Liver. Secretes bile that emulsifies fats . Bile provide alkaline medium for digestion of proteins.