Tag: respiratory system

Questions Related to respiratory system

If a respiratory surface dries out, gas exchange will 

zoology respiratory system phases in respiration human respiratory system parts of respiration

  1. Increase

  2. Decrease

  3. Stop

  4. Not be affected

Show answer
Correct Option: B
Explanation:

The respiratory surface needs moisture for maximum efficiency. Oxygen from the air dissolves in the water on the surface momentarily and this allows the oxygen more time to cross the alveolar membrane. If the surface dries out, gas exchange will happen at a very reduced rate since fast-moving gaseous oxygen molecules do not efficiently cross the alveolar membrane. The reduced gas exchange is mostly likely not enough to support blood oxygenation for vital functions. 

Therefore, the correct answer is option B.

Diffusion is insufficient to meet $...............$ requirements of multicellular organisms.

zoology respiratory system phases in respiration human respiratory system parts of respiration

  1. Carbon dioxide

  2. Oxygen

  3. Nitrogen

  4. Sulphur

Show answer
Correct Option: B
Explanation:

Diffusion is insufficient to meet the oxygen requirement of multicellular organisms like human because all the cells are not direct contact in environment and diffusion is a slow process. Diffusion is too slow to cover the distance between the gas exchange surface and the sites where the oxygen is required. That is why we need a gas transport system - the bloodstream. It would be difficult to allow passive diffusion to transfer oxygen because there would need to be gradients across each and every cell. In the end, it would be too slow and impractical for any multicellular organism to use.

Match column I with column II and select the correct option from the given codes. 

Column I Column II
(A) Trachea (i) $PO _{2}$ in alveolar air 
(B) Respiratory centre (ii) ATP 
(C) Yeast (iii) Cartilaginous rings
(D) Insects (iv) Medullaoblongata
(E) Fish (v) Larynx
(F) Biologically useful energy (vi) Tracheal respiration
(G) 100mm Hg (vii) Ethanol
(H) Vocal cords (viii) Branchial respiration
zoology respiratory system phases in respiration human respiratory system parts of respiration

  1. A-(iii), B-(iv), C-(vii), D-(vi), E-(viii), F-(ii), G-(i), H-(v)

  2. A-(v), B-(ii), C-(vii), D-(viii), E-(vi), F-(iv), G-(i), H-(iii)

  3. A-(vi), B-(iv), C-(viii), D-(v), E-(i), F-(ii), G-(iii), H-(vii)

  4. A-(i), B-(v), C-(vii), D-(iii), E-(viii), F-(ii), G-(iv), H-(vi)

Show answer
Correct Option: A
Explanation:

  • Trachea consists of C-shaped cartilaginous rings that support the walls of the trachea and prevent its collapse during inspiration. 
  • Respiratory centre is located in the medulla oblongata. 
  • Yeast undergoes anaerobic respiration to produce ethanol and $CO _{2}$. 
  • The type of respiration in insects and fish is tracheal respiration and branchial respiration respectively. 
  • ATP is a biologically useful energy produced during respiration. 
  • The partial pressure of $O _{2}$ in alveolar air is approximately 104 mm Hg. 
  • Vocal cords are present inside the larynx.
So the current option is A.

State whether the following statements are true or false.
Because $NAD^+$ and FAD are critical coenzymes in cellular respiration, huge quantities must be synthesized in the cell to ensure there is no shortage.

zoology respiratory system phases in respiration human respiratory system parts of respiration

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

NAD+ and FAD are co-enzymes required for the completion of many biochemical pathways. However, there is no need for an enormous amount of synthesis of either of these co-enzymes as there as a mechanism of recycling the co-enzymes after completion of one step in the metabolic pathway. These co-enzymes are predominantly required for the synthesis of ATP (energy currency of the cell) and will be used in the electron transport chain for the production of the same. So, they are not required to be synthesized in huge quantities but they play a crucial role in cell energetics.

So, the correct statement is 'False'. 

The breakdown of pyruvate to give carbon dioxide, water and energy takes place in

zoology respiratory system do plants breathe? plant respiration respiration-plants

  1. Cytoplasm

  2. Mitochondria

  3. Chloroplast

  4. Nucleus

Show answer
Correct Option: B

Select the correct option:

Mercury (Hg) is generally used in anaerobic respiration experiments because it does not react with ___________.

zoology respiratory system do plants breathe? plant respiration respiration-plants

  1. ${O} _{2}$

  2. ${CO} _{2}$

  3. ${H} _{2}O$

  4. $air$

Show answer
Correct Option: C
Explanation:
Mercury is very reactive towards oxygen. It reacts with the oxygen in the air and also reacts with dilute acids containing oxygen. However, mercury is comparatively non-reactive in water. This is why it is used in anaerobic respiration experiments.
So, the correct answer is '$H _2$O'

2 NADH $(H^+)$ produced during anaerobic glycolysis yield

zoology respiratory system do plants breathe? plant respiration respiration-plants

  1. 6 ATP molecules

  2. 4 ATP molecules

  3. 8 ATP molecules

  4. None of the above

Show answer
Correct Option: D
Explanation:

The process of glycolysis yields 2 net ATPs and 2 NADH molecules. NADH is converted into ATP in mitochondrial electron transport chain if oxygen is present. In anaerobic respiration, there is no oxygen available so NADH does not lead to the formation of ATP molecules. Without oxygen, NADH builds up and the cell can run out of NAD. Without NAD glycolysis stops. To regenerate NAD, cells with anaerobic respiration carry out the process of fermentation in which NADH gets converted into NAD to restart glycolysis. 

Thus, the correct answer is option D. 

When yeast and sugar solution are left to stand without oxygen for some time they develop a characteristic smell due to the production of new compound, which is

zoology respiratory system do plants breathe? plant respiration respiration-plants

  1. Ethanol

  2. Ammonia

  3. Carbondioxide

  4. Sodium carbonate

Show answer
Correct Option: A
Explanation:
When yeast has both sugar and oxygen available to it, it undergoes aerobic respiration to produce energy, water and carbon dioxide. In the absence of oxygen, yeast switches over to a process called anaerobic respiration. During which, sugar is fermented to produce energy, carbon dioxide, and ethanol. Yeast that produces ethanol from the sugar has a characteristic smell and this process is generally used to ferment wine.
So, the correct answer is 'Ethanol'.

The growth of which group of bacteria will be slow in comparison to the others?

zoology respiratory system do plants breathe? plant respiration respiration-plants

  1. Obligate aerobes

  2. Obligate anaerobes

  3. Facultative aerobes

  4. Facultative anaerobes

Show answer
Correct Option: A
Explanation:
  • The growth of Obligate aerobes will be slow in comparison to the other bacteria.
  • These group of bacteria require oxygen to grow as they cannot respire anaerobically.
  • Its growth depends on aerobic respiration and use oxygen as a terminal electron acceptor.
  • The correct answer is OPTION A.

State if the following statements are True or False. Correct the False statement.


1. Photosynthesis and respiration take place all the time in plants.
2. For respiration, sunlight and chlorophyll are needed.
3. In old stems, gaseous exchange takes place through the stomata.
4. Photosynthesis occurs only in chlorophyll-containing plants.
5. Respiration which requires oxygen is known as anaerobic respiration.
6. Aerobic respiration takes place in the absence of oxygen.

zoology respiratory system do plants breathe? plant respiration respiration-plants

  1. True

  2. False

Show answer
Correct Option: A
Explanation:
Correct statements
1. Photosynthesis and respiration take place all the time in plants.
2. For respiration, sunlight and chlorophyll are needed.
3. In stem and plants, gaseous exchange take place through the stomata.
4. Photosynthesis occurs only in chlorophyll containing plants.
5. Respiration which requires oxygen is known as Aerobic respiration.
6. Anarobic respiration takes place in the absence of oxygen.