High School

Which of the following regarding the basic differences between aerobic pathways and anaerobic pathways is true?

1. The aerobic pathway requires oxygen and the anaerobic pathway does not require oxygen.
2. The aerobic pathway is common to yeasts, while the anaerobic pathway is common to animal muscle cells.
3. The aerobic pathway results in lactic acid or alcohol, while the anaerobic pathway results in CO2 and water.
4. The aerobic pathway is a catabolic pathway and the anaerobic pathway is an anabolic pathway.

Answer :

The question asks about the differences between aerobic and anaerobic pathways, which are processes related to cellular respiration in biology.

  1. The aerobic pathway requires oxygen and the anaerobic pathway does not require oxygen.

    • This statement is true. The aerobic pathway needs oxygen to proceed, while the anaerobic pathway occurs in the absence of oxygen. Aerobic respiration takes place in the mitochondria, using oxygen to completely break down glucose into carbon dioxide (CO2) and water (H2O), releasing energy. Anaerobic respiration or fermentation occurs in the cytoplasm, allowing cells to produce energy without oxygen.
  2. The aerobic pathway is common to yeasts, while the anaerobic pathway is common to animal muscle cells.

    • This statement is not entirely accurate. Aerobic respiration is common in many organisms, including yeasts and animal muscle cells when oxygen is present. However, when oxygen is lacking, yeast undergoes anaerobic respiration (fermentation) to produce alcohol, while animal muscle cells switch to anaerobic respiration, specifically lactic acid fermentation, to meet energy demands temporarily.
  3. The aerobic pathway results in lactic acid or alcohol, while the anaerobic pathway results in CO2 and water.

    • This statement is false. Aerobic respiration produces CO2 and water as byproducts. Anaerobic respiration in muscle cells results in lactic acid, and in yeast results in alcohol and CO2.
  4. The aerobic pathway is a catabolic pathway and the anaerobic pathway is an anabolic pathway.

    • This statement is incorrect. Both aerobic and anaerobic pathways are catabolic because they involve the breaking down of molecules (like glucose) to release energy.

Therefore, the correct choice is Option 1: 'The aerobic pathway requires oxygen and the anaerobic pathway does not require oxygen.' This option correctly highlights the key difference between these two types of respiration.