Question

which of the following is one of the great advantages of moving materials by active transport? the process has no energy cost. the process is not dependent on a concentration gradient. carrier proteins are not necessary. receptor sites are not necessary for the process to occur. i dont know yet

Explanation:

To solve this, we analyze each option based on active transport knowledge:

• Option 1: Active transport requires energy (e.g., ATP), so "no energy cost" is wrong.
• Option 2: Active transport moves substances against their concentration gradient, so it's not dependent on a concentration gradient (unlike passive transport). This is correct.
• Option 3: Active transport needs carrier proteins (e.g., pumps), so "carrier proteins not necessary" is wrong.
• Option 4: Some active transport (e.g., receptor - mediated endocytosis) uses receptor sites, and even primary/secondary active transport has mechanisms that rely on protein - mediated processes related to recognition, so this is wrong.

Answer:

The process is not dependent on a concentration gradient.