Plankton, Benthos and Nekton

Freshwater Ecosystems

Read the passage below and answer the questions that follow.

Aquatic ecosystems contain several types of organisms that are grouped by their location and by their adaptations. Three groups of aquatic organisms include plankton, nekton, and benthos. Plankton are the organisms that float near the surface of the water. Two types of plankton are microscopic plants called phytoplankton, and micro scopic animals called zooplankton. Phytoplankton produce most of the food for an aquatic ecosystem. Nekton are free-swimming organisms, such as fish, turtles, and whales. Benthos are bottom-dwelling organisms, such as mussels, worms, and barnacles. Many benthic organisms live attached to hard surfaces. Decomposers, organisms that break down dead organisms, are also a type of aquatic organism.

1. How are organisms in an aquatic ecosystem grouped?

• a. by size and shape

• b. by the food they eat

• c. by how they reproduce

• d. by location and adaptations

Aquatic ecosystems contain several types of organisms that are grouped by their location and by their adaptations. Three groups of aquatic organisms include plankton, nekton, and benthos. Plankton are the organisms that float near the surface of the water. Two types of plankton are microscopic plants called phytoplankton, and micro scopic animals called zooplankton. Phytoplankton produce most of the food for an aquatic ecosystem. Nekton are free-swimming organisms, such as fish, turtles, and whales. Benthos are bottom-dwelling organisms, such as mussels, worms, and barnacles. Many benthic organisms live attached to hard surfaces. Decomposers, organisms that break down dead organisms, are also a type of aquatic organism.

Where do many benthic organisms live?

• a. attached to hard surfaces

• b. in open water

• c. near the surface of the water

• d. attached to benthos

Aquatic ecosystems contain several types of organisms that are grouped by their location and by their adaptations. Three groups of aquatic organisms include plankton, nekton, and benthos. Plankton are the organisms that float near the surface of the water. Two types of plankton are microscopic plants called phytoplankton, and micro scopic animals called zooplankton. Phytoplankton produce most of the food for an aquatic ecosystem. Nekton are free-swimming organisms, such as fish, turtles, and whales. Benthos are bottom-dwelling organisms, such as mussels, worms, and barnacles. Many benthic organisms live attached to hard surfaces. Decomposers, organisms that break down dead organisms, are also a type of aquatic organism.

How many groups of aquatic organisms are discussed in this passage?

• a. 2

• b. 3

• c. 5

• d. 4

Aquatic ecosystems contain several types of organisms that are grouped by their location and by their adaptations. Three groups of aquatic organisms include plankton, nekton, and benthos. Plankton are the organisms that float near the surface of the water. Two types of plankton are microscopic plants called phytoplankton, and micro scopic animals called zooplankton. Phytoplankton produce most of the food for an aquatic ecosystem. Nekton are free-swimming organisms, such as fish, turtles, and whales. Benthos are bottom-dwelling organisms, such as mussels, worms, and barnacles. Many benthic organisms live attached to hard surfaces. Decomposers, organisms that break down dead organisms, are also a type of aquatic organism.

Which groups of aquatic organisms are discussed?

• a. phytoplankton and zooplankton

• b. plankton, nekton, and benthos

• c. plankton, nekton, benthos, and decomposers

• d. plankton, phytoplankton, zooplankton, nekton, and benthos

Tags

NGSS.MS-LS2-2

Aquatic ecosystems contain several types of organisms that are grouped by their location and by their adaptations. Three groups of aquatic organisms include plankton, nekton, and benthos. Plankton are the organisms that float near the surface of the water. Two types of plankton are microscopic plants called phytoplankton, and micro scopic animals called zooplankton. Phytoplankton produce most of the food for an aquatic ecosystem. Nekton are free-swimming organisms, such as fish, turtles, and whales. Benthos are bottom-dwelling organisms, such as mussels, worms, and barnacles. Many benthic organisms live attached to hard surfaces. Decomposers, organisms that break down dead organisms, are also a type of aquatic organism.

Most of the food for an aquatic ecosystem is produced by

• a. worms

• b. phytoplankton.

• c. zooplankton.

• d. fish.

Tags

NGSS.MS-LS1-6

Aquatic organisms that float near the surface of the water are called ?

• a. Nektons

• b. Planktons

• c. Benthos

• d. None of the above

Aquatic organisms that break down dead organisms are called ?

• a. Decomposers

• b. Producers

• c. Carnivores

• d. Omnivores

Tags

NGSS.MS-LS2-3

Microscopic plants are called

• a. Zooplankton

• b. Algae

• c. Plankton

• d. Decomposers

Microscopic animals are called

• a. Plankton

• b. Fungi

• Zooplankton

• d. Decomposers

Aquatic organisms that dwell at the bottom of the water

• a. True

• b. False