Question

Macro-consumer organisms in pond water:
A. Minute floating plants
B. Insect larva and fish
C. Microorganisms
D. Plankton

Answer 1

Hint: Pond represents a self-sustainable freshwater ecosystem. The main features of the pond ecosystem are the presence of abundant vegetation, a large number of microorganisms, plants and animals with shallow and standing water. Pond ecosystem is made up of biotic components such as producers, consumers and decomposers. The consumers in the pond ecosystem vary from zooplanktons to big fishes.

Complete answer:
Option A) minute floating plants: Minute floating plants float on the surface of the pond and get their nutrients from the water. These aquatic plants help to oxygenate the pond water. They absorb the excess nutrients in the pond water and prevent algal bloom. However, they are not the biggest consumer present in the pond
Option A is incorrect.
Option B) insect larva and fish: Insect larvae such as mosquito larvae, dragonfly larvae, may fly larvae etc are called primary consumers and they feed on phytoplankton. The fishes in the pond are usually smaller in size and are called secondary consumers. They feed on primary consumers. This option is correct because fish is a macro consumer in the given options.
Option B is correct
Option C) Microorganisms: Some of the microorganisms in the pond include arthropods, bacteria, protozoa, hydras and algae. They help decompose organic matter in the pond. They are food for other primary and secondary consumers. They are not the macro consumers in the pond.
Option C is incorrect
Option D) Planktons: Planktons are of two types- phytoplankton and zooplankton. Phytoplankton is a producer which makes its own food through photosynthesis. Zooplankton in pond ecosystems such as Paramecium, Daphnia, Cyclops depends on phytoplankton for their food. Since this option has a producer, it is not correct.
Option D is incorrect

Hence, Option B) Insect larva and fish is the correct answer.

Note:
Pond Ecosystems are of great significance. They provide habitat to many living species and support biodiversity. All components of the food chain can be seen in ponds. They act as a reservoir which helps to drain fields during rain. Ponds recycle the nutrients present in it. They also provide drinking water to animals.