If animals don't adapt to it they can die.
The red tides are caused because of the algal blooms, which discolor the ocean's water. These tides are red because of the presence of the pigments known as phycobilin. The blue phycocynin and red phycoerythrin contributes to the red color of these tides. The chlorophyll a contained in most of these algae are seen only when the algal blooms although at other times they are still present but deep in the ocean where they cannot be seen.
The green tides will be produced when the green algae, chlorophyta, blooms. These algae obtain energy from the sun for photosynthesis.
Though most of these are correct, I personally think that 'g' is the best answer.
Cross over is the first way genes are shuffled to give rise to genetic diversity. Cross over takes place in sexual reproduction. The normal way that cross over occurs is chromosomes line up side by side and break off pieces of themselves, then trade those pieces with each other.
If they break the pieces at the same locus in the sequence of base pairs, the result is an exchange of genes called genetic recombination and it ensures that the daughter cells produced have a different genetic makeup from the parent cell and thus diversity occurs.
