Students can Download Science Chapter 10 Respiration in Organisms Questions and Answers, Notes Pdf, KSEEB Solutions for Class 7 Science helps you to revise the complete Karnataka State Board Syllabus and to clear all their doubts, score well in final exams.
Karnataka State Syllabus Class 7 Science Chapter 10 Respiration in Organisms
Class 7 Science Respiration in Organisms Textbook Exercise Questions and Answers
Question 1.
Why does an athlete breathe faster and deeper than usual after finishing the race?
Answer:
During the race, an athlete puts in more effort for obtaining more energy. It requires more oxygen to breakdown the food for the supply of energy. Hence, an athlete breathes faster and deeper than usual after finishing the race.
Question 2.
List the similarities and differences between aerobic and anaerobic respiration.
Answer:
Similarities
Food is oxidized in both cases and energy is released. It yields by-products and takes place in a cell.
Differences
Carbon dioxide and water are the end products of aerobic respiration, while alcohol is the end product of anaerobic respiration. Aerobic respiration releases more energy than anaerobic respiration.
Question 3.
Why do we often sneeze when we inhale a lot of dust-laden air?
Answer:
When dust particles enter our nostrils, it trig- gas a message to the brain. The brain instructs the nasal chamber to initiate sneezing. This is a method to remove the unwanted dust particles from the nostrils. Sneezing is a type of defence mechanism used by our bodies.
Question 4.
Take three test tubes. Fill 3/4th of each with water. Label them A, B and C. Keep a snail in test tube A, a water plant in test-tube B and in C, keep snail and plant both. Which test-tube would have the highest concentration of CO2?
Answer:
Test tube A will have the highest concentration of CO2 because snail exhales CO2 and inhales O2. Hence, CO2 concentration increases in test tube A. Test tube B contains a water plant which takes in CO2 for photosynthesis and hence CO2 concentration would be less. Test tube C contains both snail and water plants. The CO2 exhaled by snail is utilized by the plant. Thus, the test tube has less CO2 concentration.
Question 5.
Tick the correct answer:
(a) In cockroaches, air enters the body through:
(i) lungs
(ii) gills
(iii) spiracles
(iv) skin
Answer:
(iii) spiracles
(b) During heavy exercise, we get cramps in the legs due to the accumulation of:
(i) carbon dioxide
(ii) lactic acid
(iii) alcohol
(iv) water
Answer:
(ii) lactic acid
(c) The normal range of breathing rate per minute in an average adult person at rest is:
(i) 9-12
(ii) 15-18
(iii) 21-24
(iv) 30-33
Answer:
(ii) 15-18
(d) During exhalation the ribs:
(i) move outwards
(ii) move downwards
(iii) move upwards
(iv) do not move at all.
Answer:
(i) move outwards
Question 6.
Match the items in Column I with those in Column II:
| Column I | Column II |
| (a) Yeast (b) Diaphragm (c) Skin (d) Leaves (e) Fish (f) Frog |
(i) Earthworm (ii) Gills (iii) Alcohol (iv) Chest cavity (v) Stomata (vi) Lungs and skin (vii) Tracheae |
Answer:
(a)-(iii);
(b)-(iv);
(c)-(i);
(d)-(v);
(e)-(ii);
(f)-(vi).
Question 7.
Mark ‘T’ if the statement is true and ‘F’ if it is false:
(a) During heavy exercise, the breathing rate of a person slows down (T/F).
(b) Plants carry out photosynthesis only during the day and respiration only at night (T/F).
(c) Frogs breathe through their skins as well as their lungs (T/F).
(d) The fishes have lungs for respiration (T/F).
(e) The size of the chest cavity increases during inhalation (T/F).
Answer:
(a). F;
(b). F
(c). T;
(d). F;
(e). T.
Question 8.
Given below is a square of letters in which different words are hidden related to respiration in organisms. These words may be present in any direction-upwards, downwards, or along the diagonals. Find the words for your respiratory system. Clues about those words are given below the square.
(i) The air tubes of insects – Trachea.
(ii) Skeletal structures surrounding the chest cavity – Ribs.
(iii) The muscular floor of the chest cavity – Diaphragm.
(iv) Tiny pores on the surface of leaf – Stomata.
(v) Small openings on the sides of the body of an insect – Spiracles.
(vi) The respiratory organs of human beings-Lungs.
(vii) The openings through which we inhale -Nostrils.
(viii) An anaerobic organism – Yeast.
(ix) An organism with a tracheal system – Ant.
Answer:
