Answer:
Density is nearly 3 cabs per hectare
Explanation:
Given -
There are three three intertidal regions.
Area of each intertidal region is
hectares.
Number of crab in the intertidal regions are as follows -
Intertidal region I - 7
Intertidal region I - 2
Intertidal region I - 6
Sum of crabs in all three regions is equal to

Total area of all three intertidal regions is equal to
hectares
Now density per hectare is equal to total population of crab divided by total area of all the three intertidal regions
Density 
Density is nearly 3 cabs per hectare
Answer:phytoplanktons are photosynthestic organism. They have the ability to produce their own food.
Explanation: Because of there small size they could absorb nutrients in the water even at lower concentration and convert it to energy need for there growth.
Its is said that phytoplanktons are one of the largest producer of oxygen gas.
Answer:
Your answer would be A. GENES
Explanation:
Answer:
The Arctic tern is a medium-sized bird around 33–36 cm (13–14 in) from the tip of its beak to the tip of its tail. The wingspan is 76–85 cm (30–33 in). The weight is 86–127 g (3.0–4.5 oz.).
Explanation:
The water molecule slows down, meaning that it freezes because When water vapor in the atmosphere cools down, it will condense and change back into liquid water, forming clouds.