Answer:
<u>Science</u> is the careful study of the structure and behaviour of the physical world, especially by watching, measuring, and doing experiments, and the development of theories to describe the results of these activities. (according to Cambridge dictionary)
Answer:
Chemical reaction
Explanation:
Chemical changes happens when a substance combines with another to form a new substance (or unexpected color, temperature or smell), called chemical synthesis or, alternatively, chemical decomposition into two or more different substances
Answer:
a. The original spraying has caused a permanent mutation, giving the insects genetic resistance to the spray.
Explanation:
This is a practical evidences of mutation and variation, as mechanisms of evolution.
The insecticide is the selective pressure. As a results of continuous spray, the parents of the present mosquitoes must have acquired certain characteristics or traits by gene mutation which makes them resistant to the selective pressure (insecticides), and therefore survive the spray in the past.
Therefore when these resistant parents mated, with high reproductive success (leading to large gene pool of these traits,); variation in the genetic composition increases as the resistant gene is passed from generations to generations in the population. Therefore, the population of present day mosquito with genetic resistance to insecticides increases.They are therefore naturally selected, and able to survive as the present day mosquitoes with high resistance to insecticides.
