The answer is A. Have you ever heard the saying, opposites attract? That comes from magnetism. Like poles repel each other while opposites attract.
It doesn't matter where you are. "Tides" happen twice (hi - lo - hi - lo) in about 24 hours and 50 minutes. Anywhere.
If it doesn't do two complete cycles in 24 hours 50 minutes, then it's not tide.
The frequency of a genotype is how often it occurs. This can be obtained by:
number of occurrences / total population
= 160 / 1000
= 0.16 or 16%
