Life Processes: Class 10 Science Q&A · Page 3
107 free answers on Life Processes (Science) for Class 10 students, across CBSE, ICSE and State boards.
Question & Answer
Questions
- ScienceClass 10CBSE
Choose the correct path of urine in our body (a) kidney → ureter → urethra → urinary bladder (b) kidney → urinary bladder → urethra → ureter (c) kidney → ureters → urinary bladder → urethra urinary bladder → kidney → ureter → urethra
Soln: Answer is (c) kidney → ureters → urinary bladder → urethra Explanation: Urine from nephron is brought to the collecting duct of kidneys where the urine enters the ureters. There are 2 ureters, each opening from one kidney into the urinary bladder. The urinary bladder stores urine and it size increases as the amount of urine collected increases. When the CNS gives a voluntary message the muscles of bl
- ScienceClass 10CBSE
Lack of oxygen in muscles often leads to cramps among cricketers. This results due to (a) conversion of pyruvate to ethanol (b) conversion of pyruvate to glucose (c) non conversion of glucose to pyruvate conversion of pyruvate to lactic acid
Soln: Answer is (d) conversion of pyruvate to lactic acid Explanation: Breakdown of Pyruvate in presence of oxygen takes place in mitochondria leading to the formation of Lactic acid. Due to workout oxygen is used for the production of energy leading to the lack of oxygen and production of lactic acid.
- ScienceClass 10CBSE
Which of the following statement(s) is (are) correct? (i) Pyruvate can be converted into ethanol and carbon dioxide by yeast (ii) Fermentation takes place in aerobic bacteria (iii) Fermentation takes place in mitochondria (iv) Fermentation is a form of anaerobic respiration (a) (i) and (iii) (b) (ii) and (iv) (c) (i) and (iv) (d) (ii) and (iii)
Answer is(c) (i) and (iv) Explanation: Fermentation is carried out by anaerobes in the cytoplasm. Hence option ii) and iii) are wrong.
- ScienceClass 10CBSE
1. Which is the first enzyme to mix with food in the digestive tract? (a) Pepsin (b) Cellulase (c) Amylase Trypsin
Soln: Answer is (c) Amylase Explanation: Amylase is secreted in mouth and acts on the starch to convert into simpler molecules. Hence Amylase is the first enzyme to mix with food in the digestive tract.
- ScienceClass 10CBSE
Choose the forms in which most plants absorb nitrogen (i) Proteins (ii) Nitrates and Nitrites (iii) Urea (iv) Atmospheric nitrogen (a) (i) and (ii) (b) (ii) and (iii) (c) (iii) and (iv) (i) and (iv)
Answer is (b) (ii) and (iii) Explanation: Plants cannot absorb atmospheric Nitrogen. They can absorb the Nitrogen in the form of Nitrates,Nitrites and Urea present in the soil.
- ScienceClass 10CBSE
The opening and closing of the stomatal pore depends upon (a) oxygen (b) temperature (c) water in guard cells concentration of CO2 in stomata
Soln: Answer is (c) water in guard cells Explanation: Opening of guard cells is facilitated by the entry of water inside guard cells. This make the guard cell become turgid. Closing of guard cells is facilitated by water coming out of guard cells. This will make the guard cells flaccid.
- ScienceClass 10CBSE
Choose the event that does not occur in photosynthesis (a) Absorption of light energy by chlorophyll (b) Reduction of carbon dioxide to carbohydrates (c) Oxidation of carbon to carbon dioxide Conversion of light energy to chemical energy
Soln: Answer is (c) Oxidation of carbon to carbon dioxide
- ScienceClass 10CBSE
Which of the following equations is the summary of photosynthesis? (a) 6CO2 + 12H2O → C6H12O6 + 6O2 + 6H2O (b) 6CO2 + H2O + Sunlight→ C6H12O6 + O2 + 6H2O (c) 6CO2 + 12H2O + Chlorophyll + Sunlight→ C6H12O6 + 6O2 + 6H2O 6CO2 + 12H2O + Chlorophyll + Sunlight→ C6H12O6 + 6CO2 + 6H2O
Answer is (c) 6CO2 + 12H2O + Chlorophyll + Sunlight→ C6H12O6 + 6O2 + 6H2O Explanation: Option a does not show the factors responsible for photosynthesis . Option b) is not a balanced equation. Option d) is wrong as it has CO2 in the
- ScienceClass 10CBSE
The internal (cellular) energy reserve in autotrophs is (a) glycogen (b) protein (c) starch fatty acid
Soln: Answer is (c) starch Explanation: Glycogen is the stored energy in animals, Plants stores energy in the form of Starch.
- ScienceClass 10CBSE
Which of the following is an incorrect statement? (a) Organisms grow with time (b) Organisms must repair and maintain their structure (c) Movement of molecules does not take place among cells Energy is essential for life processes
Answer is (c) Movement of molecules does not take place among cells Explanation: Movement of molecule is a vital process. Movement of molecules in cells take place in active and passive modes such as Diffusion, osmosis, facilitated diffusion etc.
- ScienceClass 10CBSE
The blood leaving the tissues becomes richer in (a) carbon dioxide (b) water (c) heamoglobin oxygen
Answer is (a) carbon dioxide Explanation: Because of respiration Carbon-di-oxide gets accumulated in tissues. Hence blood leaving the tissues becomes richer in Carbon-di-oxide.
- ScienceClass 10CBSE
Oxygen liberated during photosynthesis comes from (a) water (b) chlorophyll (c) carbon dioxide glucose
Answer is (a) water Explanation: During photosynthesis water molecule splits to produce Oxygen and Hydrogen Ions. Oxygen is expelled out of plants and Hydrogen is used to reduce Carbon-di-oxide to produce carbohydrates.
- ScienceClass 10CBSE
The filtration units of kidneys are called (a) ureter (b) urethra (c) neurons nephrons
Answer is (d) nephrons Explanation: Nephron is called as the functional unit of kidney. It helps in removing the waste products and excess substances from our body.
- ScienceClass 10CBSE
Choose the correct statement that describes arteries. (a) They have thick elastic walls, blood flows under high pressure; collect blood from different organs and bring it back to the heart (b) They have thin walls with valves inside, blood flows under low pressure and carry blood away from the heart to various organs of the body (c) They have thick elastic walls, blood flows under low pressure; carry blood from the heart to various organs of the body (d) They have thick elastic walls without valves inside, blood flows under high pressure and carry blood away from the heart to different parts of the body.
Answer is (d) They have thick elastic walls without valves inside, blood flows under high pressure and carry blood away from the heart to different parts of the body.
- ScienceClass 10CBSE
In which of the following vertebrate group/groups, heart does not pump oxygenated blood to different parts of the body? (a) Pisces and amphibians (b) Amphibians and reptiles (c) Amphibians only Pisces only
Soln: Answer is (d) Pisces only Explanation: This is because of single circulation where deoxygenated blood from all part of the body is pumped into heart. From heart it is p
- ScienceClass 10CBSE
Single circulation i.e., blood flows through the heart only once during one cycle of passage through the body, is exhibited by (a) Labeo, Chameleon, Salamander (b) Hippocampus, Exocoetus, Anabas (c) Hyla, Rana, Draco Whale, Dolphin, Turtle
Answer is (b) Hippocampus, Exocoetus, Anabas Explanation: In Option a) Chameleon is a reptile and Salamander is an amphibian which are having 3 chambered hearts and show partial double circulation. In Option c) all are Amphibians and they show partial double circulation. In option d) Whale is a mammal but turtle is a reptile hence option d) is wrong.
- ScienceClass 10CBSE
What prevents backflow of blood inside the heart during contraction? (a) Valves in heart (b) Thick muscular walls of ventricles (c) Thin walls of atria All of the above
Answer is (a) Valves in heart Explanation: Walls in the heart are responsible for only pumping of the blood and they are not responsible in blocking backflow of blood inside the heart during contraction.
- ScienceClass 10CBSE
Which of the following statement (s) is (are) true about heart? (i) Left atrium receives oxygenated blood from different parts of body while right atrium receives deoxygenated blood from lungs (ii) Left ventricle pumps oxygenated blood to different body parts while right ventricle pumps deoxygenated blood to lungs (iii) Left atrium transfers oxygenated blood to right ventricle which sends it to different body parts (iv) Right atrium receives deoxygenated blood from different parts of the body while left ventricle pumps oxygenated blood to different parts of the body (a) (i) (b) (ii) (c) (ii) and (iv) (i) and (iii)
Soln: Answer is (c) (ii) and (iv) Explanation: Oxygenated blood circulates through left part of the heart whereas deoxygenated blood circulates through right part of the heart. Atrium receives blood and ventricle pumps the blood out of the heart.
- ScienceClass 10CBSE
During respiration exchange of gases take place in (a) trachea and larynx (b) alveoli of lungs (c) alveoli and throat throat and larynx
Soln: Answer is (b) alveoli of lungs Explanation: Trachea, Larynx provide a passage for the movement of air. Gas exchange takes place in Alveoli of lungs. From alveoli oxygen diffuses into blood and Carbon-di-oxide exhaled out of blood.
- ScienceClass 10CBSE
Which is the correct sequence of air passage during inhalation? (a) Nostrils larynx pharynx trachea lungs (b) Nasal passage trachea pharynx larynx alveoli (c) larynx nostrils pharynx lungs Nostrils pharynx larynx trachea alveoli
Answer is (d) Nostrils ® pharynx ® larynx ® trachea ® alveoli Explanation: Air enter respiratory system through nostrils through nostrils, passes to pharynx,larynx, trachea and then to alveoli. After inhalation diaphragm and intercoastal muscles contract along with expansion of thoracic muscles which creates enough space for the air to enter into the lungs.