Matric Notes Biology Class 9th Ch 7 Bioenergetics Extra Short & Long Questions
Short Questions
Lactic acid fermentation | Alcoholic fermentation |
Lactic acid fermentation refers to a metabolic process by which glucose is converted into lactic acid and cellular energy. | Alcoholic fermentation refers to a metabolic process by which glucose is converted into ethanol and carbon dioxide. |
Occurs in bacteria, yeast and muscle cell. | Occurs in yeast and other microorganisms. |
Used in the production of yogurt and cheese. | Used in the production of bread, beer, wine, and vinegar. |
Long Questions
The mechanism of photosynthesis involves two steps:
- Light Reaction
- Dark Reaction
iii) Effect of Temperature:
Optimum temperature is necessary for a normal process of photosynthesis. An increase and decrease in temperature negatively affect the rate of photosynthesis. Generally, a temperature, ranging between 20°C and 30°C is most suitable for photosynthesis. When the temperature exceeds 30°C, the rate of photosynthesis lowers down. Similarly, at low temperatures, the rate declines, and at freezing temperature, it stops completely. However, plants growing in dry and hot localities and in cold regions have developed adaptations for high and low temperatures.
Q.3) Why is aerobic respiration considered to be more efficient than anaerobic respiration?
Answer: Aerobic respiration is more efficient than anaerobic because it completely breaks down the food molecules and results in the release of all the energy stored in the bonds of a glucose molecule, while anaerobic respiration involves the incomplete breakdown of glucose molecule resulting in the release of less energy. Net gain of energy in the aerobic process is 36 ATP, while only 2 ATP molecules are produced from one glucose molecule in the anaerobic process. Thus, aerobic respiration is far more efficient than anaerobic.