Answer:
Option (D)
Explanation:
In terms of chemistry, a catalyst is usually defined as the substance that is commonly used in a reaction in order to increase the rate of reaction, without getting consumed. It helps in the reduction of activation energy.
In the given case, the lever or a person can be considered as a catalyst because both of these will increase the efficiency (or rate) in removing the rock from the top of the perch. Thus, the lever or the human will remain the same after the removal of rock as a catalyst can be recovered after the reaction.
Therefore, the correct answer is option (D).
Answer:
The correct answer is option c. "The gametes must be kept wet to avoid desiccation".
Explanation:
External fertilization is an adaption were species reproduce sexually, but there is no direct contact between the female and the male species, because the egg is fertilized outside the female's body. This adaptation occurs more often in aquatic animals because the gametes must be kept wet to avoid desiccation and allow fertilization, which occurs much more easily on aquatic environments.
Extinction is the term used when all members of a species dies and is never seen again
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