Class 10 Science Chapter 5 Board Questions

The green dot like structures in some cells observed by a student when a leaf peel was viewed under a microscope are chloroplasts. The green colour is due to the presence of green pigment, chlorophyll.

The difference is in autotropic nutrition; Organism obtain their food from inorganic substances. In heterotrophic nutrition, organism derive their food from organic substance.

Multicellular organism need more O₂ to perform various body function. They therefore, have special organs for exchange of gases.

Transpiration

Respiration uses oxygen and release carbon dioxide but in photosynthesis carbon dioxide is used and oxygen is released.

Glucose → Pyruvate + Energy + Oxygen → CO₂ + H₂O + Energy

Starch is produce in the uncovered part of the leaf which turns blue black in presence of iodine solution.

Platelets

Because the dissolved oxygen is fairly low in water compared to the amount of oxygen in the air.

Phloem transports soluble product of photosynthesis in a plant.

Small intestine.

Holozoic nutrition.

The amount of oxygen dissolved in water is very low, as compare to amount of oxygen in air. Thus, terrestrial organism has to make less efforts to obtain oxygen then an aquatic organism to obtain oxygen for respiration.

The two ways in which glucose is oxidised to provide energy in various organism are aerobic respiration pathway which uses oxygen to breakdown glucose completely into carbon dioxide and water and some use other pathways that do not involve oxygen which is called anaerobic respiration pathway.

Plant get carbon dioxide from atmosphere through stomata and water from soil through roots and transports to leaves.

The process by which plant lose water in the form of vapour from aerial plant of the plant is known as transpiration.

Xylem transport water and mineral in the plant.

Autotrophs obtain carbon dioxide from atmosphere and nitrogen from soil to make their food.

Trypsin

Saliva contains an enzyme called salivary amylase that breakdown starch.

(i) Blood Plasma,

(ii) RBC

Movement of water and mineral soil to other parts of plant will stop and the plant will ultimately die if is xylem is removed.

The green dots indicate chloroplast and the green colour is due to chloroplast pigment present in chloroplast.

In multicellular organism all the cells are not in direct contact with the surrounding environment. Thus simple diffusion does not meet the requirement of all the cells.

During running the sportsman require large amount of energy instantly. In order to release more energy, Pyruvate is converted into lactic acid in the absence of oxygen. Accumulation of lactic acid in the muscle causes cramps.

Saliva is a watery fluid secrete by the salivary gland in the mouth. In the mouth, Food get mixed up with saliva secrete by salivary gland. Saliva contain an enzyme Salivary amylase which breaks polysaccharide starch into disaccharide maltose(sugar)

The final product after digestion of carbohydrate is glucose and protein is amino acid.

Arteries: They are vessels which carry blood away from the heart to various organ of the body.
Arteries have thick elastic walls; since the blood is under high pressure.

Veins: Vein collect the blood from the different organ and bring it back to the heart.
They don’t have thick wall, because the blood is no longer under pressure.

In human beings, to maximize the area for exchange of gases in a surface of lunge has smaller tubes that terminate into balloon like structure called alveoli. The walls of alveoli have extensive network of blood vessels.

Physical forces (like transpiration pull and root pressure) help in transportation of water ion Xylem while translocation of food help in Phloem is achieved by utilizing energy. No energy required for water transport in xylem, energy required for translocation of food in phloem.

Function of the following components of the transport system in human being are as follow:
(i) Blood vessels: There are three types of blood vessels of different sizes involved in blood circulation viz. arteries, veins, and capillaries which are all connected to form a continuous closed system.

(ii) Blood Platelets: They help in coagulation of blood and are called thrombocytes.

(iii) Lymph: It carries digested and absorbed fat from intestine and drains excess fluid from extra cellular space back into the blood.
(iv) Heart: It is a pumping organ that receives blood from the veins and pumping it into the arteries.

In small intestine complete digestion of various component of food take place. The process of digestion of food in mouth, stomach and small intestine in human body are as follows:
Mouth: Digestion of food begin in the mouth. Saliva present in mouth contain a digestive enzyme called saliva amylase which breakdown starch into sugar.
Stomach: Stomach store and mixes the food received from oesophagus with gastric juices. The main component of gastric juice are hydrochloric acid dissolves bits of food and create an acidic medium. In this medium pepsinogen is converted to pepsin which is a protein digestive enzyme. Mucus protected the inner lining of the stomach from the action of HCL.
Small intestine: Small intestine is the site of complete digestion of carbohydrates, fats and protein. Small intestine produce intestinal juice from the gland present in its wall. The intestinal juice helps in further digestion of food. Small intestine also obtains digestive juice from liver and pancreas that helps in mixing of food. The liver produce bile juice that causes emulsification of fats and the pancreas produce pancreatic juice for digesting protein and emulsified fats. This digested food is finally absorbed through the intestinal walls.

Arteries
1. They carry oxygenated blood.
2. They carry blood from heart to various organs.
3. They are thick walled.

Veins
1. They carry deoxygenated blood.
2. They carry blood from various organs to heart.
3. They are thin walled.

Arteries
1. Arteries carry oxygenated blood from heart to various organs of the body .
2. They are thick walled.

Veins
1. Veins carry deoxygenated blood from various organs to the heart.
2. They are thin walled.

Capillaries
1. exchange of materials between blood and surrounding cell take place in the capillaries.
2. They are thin walled and extremely narrow tube or blood vessel which connected arteries to veins.

(i) Even through the breathing cycle is rhythmic the lungs always contain a residual volume of air so that absorption of oxygen and release of carbon dioxide becomes continuous.

(ii) The circulatory system will become inefficient if it develops a leak this could be avoided by maintaining a normal blood pressure.

(iii) When water flows into the guard cells the guard cell swell and the stomata pore open up. The guard cell shrink when water moves out and the stomata pore closes.

Function of kidney: It remove the nitrogenous waste such as urea and excessive water from the blood. It regulates the osmotic pressure/ water balance/ pH of the blood.
Function of ureter: Urine formed in each kidney is carried by the long tube called ureter. To the urinary bladder some amount of glucose, amino acid and a measure amount of water are reabsorbed in ureter.
Function of urinary bladder: It act as a reservoir that stores urine before being discharged to the outside.
Function of urethra: Urine is passed out from the body through the urethra.

The circulatory system of man is called double circulation system. As the blood passes through the heart twice in one complete cycle of the body. It involves two circulations.

(i) Pulmonary circulation: This circulation is maintaining by the right side of the heart. It begins in the right ventricle which expels the blood into the pulmonary trunk. The blood flowing into the muscular system of the lungs becomes oxygenated and return to the heart (left atrium) through pulmonary veins.

(ii) Systematic circulation: This circulation is maintaining by the left ventricle which send the blood into the aorta. The aorta divides into arteries, aertioles and finally to the capillaries and them by supplies oxygenated blood to various parts of the body. From their deoxygenated blood is collected by venules which join to form veins and finally vena cava and pour blood back into the heart.

(iii) Necessity of double circulation system: The right side and the left side a useful to keep deoxygenated and oxygenated blood from being from mixing this type of separation of oxygenated and deoxygenated blood ensures a highly efficient supply of oxygen to the body this is useful in case of human because it constantly give energy to maintain their body temperature.

(i) The two different ways in which glucose is oxidised to provide energy to the organism are as follow: First set of breakdown of glucose (six carbon molecules) take place in cytoplasm cell of all organism. This process yield three carbon molecules compound called pyruvate take place in different manner in different organism.
(a) Anaerobic respiration which take place in absence of oxygen example in yeast during fermentation. In this case pyruvate is converted into ethanol and carbon dioxide.
(b) Aerobic respiration in which break down of pyruvate take place in presence of oxygen two rise to three molecules of carbon dioxide and water.

(ii) The two difference between the two ways of oxidation of glucose in organism, are as follow:
Aerobic respiration
1. When oxidation of food nutrients occur in the presence of the molecular oxygen it is called aerobic respiration.
2. More energy is produced as oxidation is complete.

Anaerobic respiration
1. When oxidation of nutrient occur without the utilization of molecular oxygen it is called anaerobic respiration.
2. Less amount of energy is produced as oxidation is not complete.

(a)The process by which autotrophic prepare their food is called photosynthesis.

(b) The three event which occur during the process of photosynthesis are as follow:
(i) Absorption of light energy by chlorophyll.
(ii) Conversion of light energy to chemical energy and splitting of water molecules into hydrogen and water.
(iii) Reduction of carbon dioxide to carbohydrate.

(c) The two source from which plants obtain nitrogen for the synthesis of protein and other compound are:
(i) In organic nitrates or nitrite.
(ii) Organic compounds prepared by bacteria from atmospheric nitrogen.

Parasites are the organism which obtain nutrient from the body of the other living organism and harm them as a result.
Plant parasite – Cuscuta.
Animal Parasite -Tapeworm.
Organism that breakdown food outside the body and then absorb it are saprophyte for example: fungi, bacteria.

(i) Fine hair and mucus present in the nasal passage so that any dust particles pathogen etc. can be trapped in here and only clean air will enter the lungs. This is of the defence mechanism of our body.

(ii) Rings of cartilage are present in throat so that the trachea doesn’t collapse on respiration.

(a)
(i) Pyruvate
(ii) Urea

(b) The undigested food material in the vacuole reach the rear end of the organism and is thrown out by the process of exocytosis. The membrane of the vesicle fuses with the surface membrane.

Aerobic respiration
1. When oxidation of food nutrients occur in the presence of the molecular oxygen it is called aerobic respiration.
2. More energy is produced as oxidation is complete.
3. It occurs in higher organism like plant and animal.

Anaerobic respiration
1. When oxidation of nutrient occur without the utilization of molecular oxygen it is called anaerobic respiration.
2. Less amount of energy is produced as oxidation is not complete.
3. It occurs in lower organisms like bacteria and yeast.

Blood:
(i) oxygen is transported to the tissue of the body for the purpose of respiration.
(ii) carbon dioxide is transported to the lungs by the blood plasma.
(iii) The digested and the absorbed nutrient are transported to the tissue.
(iv) Nitrogenous waste are transported to the kidney.
(v) The blood regulates the body temperature.
(vi) It maintain the ph of the body tissue.
(vii) It transported various hormone from one region to another and bring about the coordination.
(viii) It maintain water balance to constant level.
(ix) The lymphocytes produce antibodies against the invading antigens and protects from the diseases.
(x) Blood helps in rapid healing of wounds by forming a clot at the site of injury.

Lymph:
(i) It carries digestive and absorbed fat from intestine and drains excess fluid from extracellular space back into the blood.
(ii) it protects the body by killing the germs drained out of the body tissue with the help of lymphocytes contained in lymph nodes.

(a) Function of stomata: Gas exchange between plant the atmosphere.
Plant loose water through stomata which help in movement of minerals from soil to leaves.

(b) Raw material for Photosynthesis. Carbon dioxide, water, chlorophyll and sunlight are the essential raw material from soil to leave.
(i) Carbon dioxide is a gas, which is released into the atmosphere during respiration. This gas is utilized by the autotrophic plants which enters the leaf through the stomata present on its surface during the process of photosynthesis.
(ii) Water is another requirement for synthesis which is transported upward through xylem tissue to the leave, from which it receive the photosynthesis cells. This water then split in the presence of sunlight and chlorophyll.
(iii) Chlorophyll. It is a green pigment in plants which act as a catalyst. It is responsible for absorption of sun energy by the plant. The chlorophyll pigment are photoreceptor molecules which plays a key role in the photosynthesis process.
(iv) Light. Light affect photosynthesis by its intensity quality and duration. In green light the rate of photosynthesis is maximum while in red and blue light the rate of photosynthesis is maximum.

Mouth: Digestion of food begin in the mouth. Saliva present in mouth contain a digestive enzyme called saliva amylase which breakdown starch into sugar.
Stomach: Stomach store and mixes the food received from oesophagus with gastric juices. The main component of gastric juice are hydrochloric acid dissolves bits of food and create an acidic medium. In this medium pepsinogen is converted to pepsin which is a protein digestive enzyme. Mucus protected the inner lining of the stomach from the action of HCL.
Small intestine: Small intestine is the site of complete digestion of carbohydrates, fats and protein. Small intestine produce intestinal juice from the gland present in its wall. The intestinal juice helps in further digestion of food. Small intestine also obtains digestive juice from liver and pancreas that helps in mixing of food. The liver produce bile juice that causes emulsification of fats and the pancreas produce pancreatic juice for digesting protein and emulsified fats. This digested food is finally absorbed through the intestinal walls.

(a) The process of allowing oxygen from enter the lungs is called breathing.
The rate of breathing during vigorous exercised increased by about 20 to 25 time per minute. It is because during vigorous exercise demand for oxygen increased. Breathing occur involuntary but its rate is controlled by the respiratory center of the brain.

(b) Translocation is the transport of food from the leave to other part of the plant and occur in the part of the vascular tissue is known as phloem.
It is essential for plants because every parts of the plant needs food for obtaining energy for building its parts and maintaining its life.
(i) Sugar is synthesized in the leaves of the plant.
(ii) Hormones are synthesised at the tips of roots and stems of plants.

(a) Since fishes are aquatic they take in oxygen dissolved in eater. They take water through their mouth which goes to their gills where the dissolved oxygen is taken up by the blood and transported. The carbon dioxide is given out through the same passage.

(b) The balloon like structure in our lungs are the alveoli. Their function are:
(i) They are very thin walled and hence help in gaseous exchange.
(ii) They contain extensive network of blood vessels which help in transport of respiratory gases.
(iii) They increases the surface area for absorption of gases.

(c) The respiratory pigment is hemoglobin. Its roles are:
(i) It has affinity for oxygen and hence helps in transport of oxygen from alveoli to body tissues.
(ii) It also has affinity for carbon dioxide and hence helps in transport of carbon dioxide from body tissue to alveoli.

(a) The process of Nutrition in green plant is photosynthesis.
The type of nutrition is autotropic nutrition. Autotropic nutrition requires sunlight, chlorophyll, water and carbon dioxide.
Plant prepare their own food in the form of glucose which gets converted into starch. This is done using carbon dioxide and water which gets fixed using energy from sunlight by the chlorophyll molecule present in green plant.

(b) The three events involved are:
(i) Absorption of sunlight by chlorophyll.
(ii) Conversion of this energy into chemical energy and splitting of water into H+ and OH-using this energy.
(iii) Reduction of carbon dioxide to carbohydrates by using H+ produced due to splitting of water.

(a) Arteries carry oxygenated blood from heart to various organs of the body. They are thick walled. Veins carry deoxygenated blood from various organs to the heart They are thin walled.
Blood: Oxygen is transported to the tissue of the body for the purpose of respiration. carbon dioxide is transported to the lungs by the blood plasma. The digested and the absorbed nutrient are transported to the tissue. Nitrogenous waste is transported to the kidney. The blood regulates the body temperature. It maintains the pH of the body tissue. It transported various hormone from one region to another and bring about the coordination. It maintains water balance to constant level. The lymphocytes produce antibodies against the invading antigens and protects from the diseases. Blood helps in rapid healing of wounds by forming a clot at the site of injury.
Heart: It is a pumping organ that receives blood from the veins and pumping it into the arteries.

(b) If there is a leak in the blood vessel due to injury then the blood platelets help plugs this leaks. The platelets make the clot by forming a mesh like structure over the leak in which other blood cells get entangled ultimately plugging the leak.