Available Answers

1. 1.

   Tick (√) the correct options:

   1. The air we breathe out during exhalation is rich in _________________.
      1. nitrogen
      2. oxygen
      3. carbon dioxide
      4. ozone
   2. Anaerobic respiration in our body muscle cells releases _________________.
      1. alcohol
      2. glucose
      3. formic acid
      4. lactic acid
2. 2.

   Tick (√) the correct options:

   1. During inhalation, the ribs are pushed _____________________.
      1. upwards
      2. downwards
      3. inwards
      4. sidewards
   2. During exhalation, the space in the chest cavity _____________________.
      1. increases
      2. decreases
      3. remains the same
      4. none of these
3. 3.

   Tick (√) the correct options:

   1. Which of the following is not associated with the process of respiration?
      1. lungs
      2. alveoil
      3. gall bladder
      4. trachea
   2. Accumulation of _______________ in the muscle cells causes muscle cramps.
      1. glacial acid
      2. acetic acid
      3. lactic acid
      4. nitric acid
   3. In fish, exchange of gases takes place through _______________.
      1. lungs
      2. spiracles
      3. body skin
      4. gills
   4. Trachea are present in a/an _______________.
      1. frog
      2. fish
      3. earthworm
      4. insect
   5. We can hold our breath only for a few _______________.
      1. seconds
      2. hours
      3. days
      4. years
   6. Alcohol is formed in _______________ respiration.
      1. aerobic
      2. anaerobic
      3. cellular
      4. leaf
   7. As the air passes through the nasal cavity, it becomes _______________.
      1. cold
      2. very cold
      3. warm
      4. hot
   8. Normal range of breathing rate in an average adult person at rest is _______________ times/minute.
      1. 9-12
      2. 15-18
      3. 21-24
      4. 30-33
   9. In cockroaches, air enters the body through _______________.
      1. lungs
      2. gills
      3. spiracles
      4. skin
   10. During exhalation, the ribs _______________.
       1. move outwards
       2. move upwards
       3. move downwards
       4. do not move at all
4. 4.

   Fill in the blanks:

   1. The number of times a person breathes in a minute is called _________________.
   2. The trachea branches into two thinner tubes called _________________.
   3. The organisms carrying out aerobic respiration are called _________________.
   4. During inhalation, the diaphragm contracts and moves _________________.
   5. After heavy exercise, we sometimes get muscle _________________.
   6. Oxygen combines with the haemoglobin in the blood to form _________________.
5. 5.

   Match the following:

   Column A	Column B
   1. Yeast	a. gills
   2. Diaphragm	b. stomata
   3. Leaves	c. chest cavity
   4. Fish	d. anaerobic respiration
   5. Moist skin	e. lungs and moist skin
   6. Frog	f. earthworm

    

6. 6.

   Name an animal that breathes through (a) tracheae, (b) gills, (c) skin and (d) lungs.