Correct answer: A). The enzyme influences the speed of change from substrate to product
The enzymes are the biological catalyst that speed up the rate of chemical reactions by decreasing the activation energy of the reaction pathway.
They increase the speed of change of substrate to the product and it remains unchanged in the reaction. Hence, it can be used again and again.
Enzymes are highly specific in nature, only a specific substrate binds to the enzyme's active site. Hence, a particular enzyme is required to catalyze a reaction.
I recall that Professor Kwang had observed amoebas that had cannibalized bacteria cells. The bacteria were slaughtering the amoebas, but somehow some survived. This particular group of amoebas contained bacteria that thrived inside it. Hence the name, endosymbiosis. However, this lucky group and it's offspring could not survive without bacteria.
d. Sea Cucumber
Sea cucumbers are filter feeder. Sea cucumbers often find places that have strong currents to find food.
C. Two atoms come together to form a molecule.
The answer to your question would be letter D