C , because Each strand of DNA acts as a template for synthesis of a new, complementary strand. Replication produces two identical DNA double helices, each with one new and one old strand.
Photosynthesis is a process that uses the soliare to produce chemical energy (glucose). This means that the algae living in the water require a supply of solar light, and for that it would be necessary that the water is clear so that the solar rays can pass and reach the algae.
In the case where these corals and algae live in a cloudy or muddy water, the sun's rays do not pass very well, and therefore the photosynthesis of these algae is altered.
Three examples of marine genetically engineered organisms are:
1. AquAdvantage salmon is genetically engineered Atlantic salmon modified in order to achieve fast growth. A growth hormone-regulating gene of Pacific salmon is introduced in the genome of Atlantic salmon.
2. Grass carp was also modified by scientist in order to enhance its protection from contagious diseases. It has been modified with a transgene coding for lactoferrin (antibacterial function). So, the, survival rate of the modified Grass carp was doubled comparing to nonmodifeied fish.
3. Zebrafish is the most commonly used for modification because it has 1-cell embryo, with clear chorion so it is easy to be micro-injected with transgenic DNA.