Understanding Biotic and Aquatic Communities from the Passage

The question asks for the meaning of 'aquatic community' based on the provided passage. To answer this, we need to carefully read the passage and identify where the term 'aquatic community' is mentioned and how it is described or defined within the text.

Defining Biotic Community in the Passage

The passage begins by defining a 'biotic community'. It states:

The grouping or assemblage of plants, animals and microbes we observe when we study a natural forest, a grassland, a pond, a coral reef or some other undisturbed area, is referred to as the area's biota or biotic community.

It further clarifies the components of a biotic community:

• Plant portion: All vegetation, from large trees to microscopic algae.
• Animal portion: Everything from large mammals to tiny insects and mites.
• Microbes: Microscopic bacteria, fungi, and protozoans.

Thus, a biotic community is essentially all the living things in a particular area.

Identifying 'Aquatic Community' in the Passage

Let's look for the term 'aquatic community' in the passage. The passage discusses how abiotic factors influence the kind of biotic community found in an area. It gives examples like deserts (lack of moisture) and forests (plenty of moisture and suitable temperature). It then states:

The presence of water is the major factor that sustains aquatic communities.

This sentence directly links the term 'aquatic communities' to the presence of water. Since a 'biotic community' is defined as the assemblage of living things, an 'aquatic community' sustained by water must refer to the living things found in water.

Evaluating the Options

Now, let's examine each option in light of the passage's definition and the context of 'aquatic communities'.

Option 1: Biotic community inhabiting the land

The passage contrasts land communities (like forests or deserts) which are influenced by moisture levels on land, with aquatic communities which are sustained by water. A biotic community inhabiting land is a terrestrial community, not an aquatic one. Therefore, this option is incorrect.

Option 2: Biotic community found in water

The passage explicitly states that "The presence of water is the major factor that sustains aquatic communities." This implies that aquatic communities are the biotic communities that exist where there is water. This option aligns perfectly with the information provided in the passage. Therefore, this option is correct.

Option 3: Biotic community found in the air

The passage discusses communities in forests, grasslands, ponds, and coral reefs, which are associated with land or water. It does not discuss biotic communities found primarily in the air. While some organisms in a community might inhabit the air temporarily (like birds), the core definition based on the passage relates to a specific area or habitat type (land or water). This option is not supported by the passage and is incorrect.

Option 4: Assemblage of rain and moisture

Rain and moisture are examples of abiotic factors mentioned in the passage that influence biotic communities. However, an 'assemblage of rain and moisture' itself is not a biotic community; it is a collection of non-living elements (abiotic factors). The term 'aquatic community' refers to the living organisms sustained by water, not the water itself. Therefore, this option is incorrect.

Conclusion: The Meaning of Aquatic Community

Based on the direct statement in the passage, "The presence of water is the major factor that sustains aquatic communities," and the definition of a biotic community as an assemblage of living organisms, an 'aquatic community' is the biotic community that is found in water or sustained by water.

Revision Table: Key Ecological Terms from the Passage

Additional Information: Ecosystem Concepts Explained

The passage introduces fundamental ecological concepts. Here's a bit more detail:

• Ecosystem: An ecosystem includes both the biotic community (all the living things) and the abiotic factors (non-living components like water, soil, air, sunlight) in a specific area, interacting together.
• Abiotic Factors: These are the physical and chemical components of an ecosystem that affect the living organisms. Examples include temperature, light, water, nutrients, salinity, pH, and soil composition. These factors determine what kinds of organisms can survive and thrive in a particular environment.
• Biotic Factors: These are the living or once-living components of an ecosystem. They include all the plants, animals, fungi, and microorganisms. Biotic factors interact with each other (e.g., predation, competition, symbiosis) and are also affected by the abiotic factors.
• Habitat: The specific place or environment where an organism or a population of organisms lives. For example, a fish's habitat is a pond (aquatic environment), while a deer's habitat is a forest (terrestrial environment).
• Community Types: Communities are often classified by their dominant features or location, such as terrestrial communities (land-based like forests, grasslands, deserts) and aquatic communities (water-based like ponds, lakes, rivers, oceans, coral reefs).

Understanding these basic concepts helps in interpreting descriptions of natural environments and the interactions within them.