Chapter 4, Problem 8STP

Summary Introduction

Introduction : 

The intertidal zone is the region that remains above water during low tide and underwater during high tide. The region is also known as seashore or foreshore and during low tide, the air is exposed to organisms. Intertidal zones houses varieties of habitats and species. Organisms living in these regions have adaptations that help them to survive in extremely harsh conditions of the environment.

Answer to Problem 8STP

Correct answer : 

The correct answer is option (c) ability to survive in moving water.

Explanation of Solution

Explanation/justification for the correct answer :

Option (c) ability to survive in moving water. Intertidal zones experience continuous flow of water or the tides from the nearby water source. The tides sometimes have low intensity and sometimes it can be of high intensity. Organisms living in these regions are easily carried away with the high-intensity tide or even in low tide. Therefore, their adaptation to survive in moving water is the most common adaption of these organisms. So, the correct answer is option (c).

Explanation for incorrect answer : 

Option (a) ability to live in total darkness. A region with total darkness is the one that does not receive sunlight. Intertidal zones are on the land surface and there is no probability of facing a condition when the organism living in these regions faces no sunlight or the region of extreme darkness. This is because even when carried away with water, these organisms remain near the surface of the water. Therefore, this is an incorrect option.

Option (b) ability to live in cold water. Organisms living in intertidal zones are adapted to survive in extreme conditions. In regions where the seawater is extremely cold to an extent of freezing point and the shore area experiences a good amount of sunlight, the organisms may have the adaptation quality to survive in cold water, but one cannot expect this adaptation to be common to all the intertidal zones. So, this is an incorrect answer.

Option (d) ability to survive without water for 24 hr. Organisms living in intertidal zones are adapted to survive in extreme conditions. In some conditions, these regions may experience extremely dry conditions but this adaptation is not common to all the intertidal zones that one can expect. Therefore, this is an incorrect option.