Question

Which among the following organisms will be able to survive the deepest level of the ocean?

• A. Nektons
• B. Red algae
• C. Neustons
• D. Planktons

Answer 1

The correct option is B Red algae

In order to trap maximum amount of sunlight, most of the algae are present on the surface or near the surface of any water-body, but red algae are present in the depth of water as well, because of the presence of excess amounts of the pigment phycoerythrin, which has the capacity to absorb blue and green light and which gives red colour to the red algae.

According to the visible light spectrum, red has the highest wavelength and least energy to penetrate deep into the water unlike the blue and green light.

Being shorter in wavelength, energy of the blue-green spectrum penetrates easily deep into water. Due to the presence of abundant amounts of pigment phycoerythrin in red algae, they absorb blue-green light deep inside the ocean and hence are found in the sea where no other photosynthetic forms generally grow.

Nektons include animals like fish, whales, and turtles etc. that actively swim throughout the water column independent of the water current.

Neustons are assemblages of organisms associated with the surface film of lakes, oceans etc.

Planktons are small microscopic organisms like zooplanktons and phytoplanktons that drift or float on the surface of water along with tides and water currents.

Basically planktons, nektons and neustons are organisms/ animals that live or swim above the benthic zone of the ocean.