Answer:
A. temperature of the reaction
B. amount of enzyme
E. pH of the reaction
Explanation:
Temperature should be kept constant because enzymes operate at different activity rates depending on the temperature. The same goes for the pH as well with different enzymes having different optimal pH levels.
The amount of enzyme should be kept constant as well because different concentrations of enzymes can determine how fast the reaction will occur.
Essentially anything that could affect enzyme activity apart from substrate concentration should be kept constant.
<span>Two main characteristics that distinguish autotrophs from heterotrophs are:
A~ Autotrophs produce their own food by either chemosynthesis or photosynthesis. Heterotrophs do not produce their own food. Heterotrophs obtain their food by consuming autotrophs or heterotrophs.
B~ Autotrophs are at the primary level in a food chain and Heterotrophs are at the secondary level or tertiary level in a food chain.</span>
A scientist who studies the interactions or interrelationships between organisms and their physical environment is an Ecologist.