Phytoplankton would most likely be found a. in the abyssal zone b. in the pelagic zone c. in the photic zone d. in the benthic zone

The correct answer for the blank is C. In the photic zone.

Photic zone is the superficial zone of the water body where sunlight penetrates and allows photosynthesis. Phytoplanktons are the microscopic plants found in the photic zone of aquatic bodies and considered as the primary producers in the food chain. It is also called the epipelagic zone ( uppermost layer of pelagic).

As light penetrates the photic zone, phytoplankton can easily synthesize food by performing photosynthesis.      

Pelagic, benthic, and abyssal are zones of the ocean in their increasing depth order.  

Thus, the correct answer is C. In the photic zone.

a tetrad is the foursome during meiosis made by two homologous chromosomes that have each already replicated into a pair of sister chromatids.

substitution is the answer in this case