Respiration
Each subtopic includes About section, revision page link, 10 preview questions, and practice CTAs.
Aerobic respiration
SubtopicAerobic respiration under Respiration for Grade 12 IGCSE.
Preview questions (no answers)
- 1.
Which of these chemical formulas represents a liquid product of aerobic respiration?
A.B.C.D. - 2.
What role does the heart play in supporting aerobic respiration in the legs of a marathon runner?
A.It produces the glucose needed
B.It pumps oxygenated blood and glucose to the leg muscles
C.It stores the carbon dioxide produced
D.It converts lactic acid into oxygen
- 3.
Which of these is an example of 'active transport' that requires energy from respiration?
A.Oxygen diffusing into the blood
B.Moving ions against a concentration gradient
C.Carbon dioxide leaving the lungs
D.Water moving into a cell by osmosis
- 4.
Which of the following substances provides the atoms for the carbon dioxide produced in respiration?
A.Oxygen gas
B.Water molecules
C.Glucose molecules
D.Nitrogen gas
- 5.
Which of the following is a direct use of the heat energy released during aerobic respiration in birds?
A.Feather growth
B.Maintaining a constant body temperature
C.Flight muscle contraction
D.Digestion of seeds
- 6.
In the balanced chemical equation , what does the represent?
A.Sucrose
B.Glucose
C.Fructose
D.Starch
- 7.
Which of the following statements about aerobic respiration in plants is TRUE?
A.Plants only respire at night
B.Plants respire all the time, but photosynthesis may mask it in the day
C.Plants do not produce carbon dioxide during respiration
D.Plants use oxygen for photosynthesis and carbon dioxide for respiration
- 8.
Which of the following best describes the role of enzymes in the mitochondrial matrix during aerobic respiration?
A.They decrease the total energy released from the glucose molecule.
B.They catalyze the decarboxylation and oxidation of organic intermediates.
C.They provide the heat necessary to keep the cell at a constant temperature.
D.They act as structural supports for the mitochondrial DNA.
- 9.
In the electron transport chain, what is the fate of the low-energy electrons after they have passed through all the protein complexes?
A.They are ejected from the cell as beta radiation.
B.They are used to reduce back to .
C.They combine with protons and oxygen to form water.
D.They are used to pump out of the matrix.
- 10.
Which of the following molecules contains the most potential energy available for the cell to extract during aerobic respiration?
A.Pyruvate
B.Acetyl-CoA
C.Glucose
D.Water
Download the worksheet for Respiration - Aerobic respiration to practice offline. It includes additional chapter-level practice questions.
Anaerobic respiration
SubtopicAnaerobic respiration under Respiration for Grade 12 IGCSE.
Preview questions (no answers)
- 1.
What is the chemical formula for glucose, the starting point for both types of respiration?
A.B.C.D. - 2.
Why does a person continue to pant after they have finished a fast run?
A.To cool down their lungs
B.To provide oxygen to convert lactic acid to carbon dioxide and water
C.To increase the amount of glucose in their blood
D.To reduce the amount of water in their body
- 3.
Which of these is NOT a product of anaerobic respiration in humans?
A.Lactic acid
B.ATP
C.Heat
D.Ethanol
- 4.
Which type of respiration provides the fastest way to regenerate ATP in a cell when oxygen is limited?
A.Aerobic respiration
B.Anaerobic respiration
C.Photosynthesis
D.Active transport
- 5.
Which statement best summarizes the relationship between glucose and lactic acid in human muscles?
A.One glucose molecule () is broken down into two lactic acid molecules ().
B.Two glucose molecules are required to make one lactic acid molecule.
C.Glucose is converted to lactic acid only when the temperature is below .
D.Lactic acid is the substrate that is broken down to produce glucose anaerobically.
- 6.
In terms of carbon balance, how many molecules of are produced from the anaerobic respiration of one molecule of glucose in yeast?
A.2
B.6
C.1
D.0
- 7.
If a sample of yeast is given a limited supply of glucose in anaerobic conditions, what will eventually limit its growth?
A.Depletion of glucose and accumulation of ethanol.
B.Excessive production of oxygen.
C.The lack of carbon dioxide in the surroundings.
D.The conversion of all ATP back into glucose.
- 8.
In the absence of the enzyme Lactate Dehydrogenase, a muscle cell undergoing intense contraction would immediately suffer from:
A.A surplus of
B.An inability to regenerate , stopping glycolysis
C.Excessive production of
D.Rapid accumulation of ethanol
- 9.
What is the physiological significance of the 'alactic' portion of the oxygen debt?
A.It represents the oxygen needed to oxidize 20% of the lactate
B.It is the oxygen required to restore the resting levels of and creatine phosphate
C.It is the oxygen used to convert glucose into glycogen
D.It accounts for the increased heart rate post-exercise
- 10.
During anaerobic respiration in yeast, how many bonds are broken per molecule of glucose to reach the final product ethanol?
A.2
B.3
C.4
D.5
Download the worksheet for Respiration - Anaerobic respiration to practice offline. It includes additional chapter-level practice questions.