Answer: The enzyme increases the effectiveness of reactant collisions thereby increasing the number of reactant molecules that reach activation energy.
A reaction occur if the substrates needed collide with each other. Enzyme is like a mold that can hold the substrate so that it will be easier to collide. The effect of enzyme could be seen in the activation energy needed to do the reaction because enzyme lower it very much. This will help speed up the reaction so it create product faster.
This spider camouflages with its environment so it is less likely to be detected by predators.
Answer: The correct answer for the first question is- B) Mechanical.
Adaptation can be described as a process of change in an organism over time that facilitates its survival in the changing environmental conditions. It results due to mutation or genetic change in the individual that gives a benefit to the organism. It exhibits change in structure ( like succulent plants in desert), function, or behavior.
Mechanical is not a type of adaptation as it deals with movement of objects.
The correct answer for second question is- C) Variations.
Variation among organisms in a population results from change in the genetic material or their genetic sequences. Change at the genetic level is thus reflected in the phenotypes ( like different color of feathers in birds).
Thus, difference is in the feather color reflects variations.