What adaptation is common among organisms living in the intertidal zone?
A Ability to endure periods of dryness and exposure to air.
B Dependence on chemosynthesis for food.
C Ability to regulate internal temperature.
D Ability to survive at extreme depths.
The correct answer and explanation is:
The correct answer is A: Ability to endure periods of dryness and exposure to air.
The intertidal zone, located between the high and low tide marks, experiences drastic changes in environmental conditions. During low tide, organisms are exposed to air and sun, which can cause dehydration and temperature fluctuations. During high tide, they are submerged in seawater, which provides moisture and stable conditions. Consequently, organisms that live in this zone have developed several key adaptations to survive these harsh fluctuations.
One critical adaptation is the ability to endure periods of dryness when exposed to air. Many intertidal organisms have specialized features that help them retain moisture during dry spells. For example, some have thick, waxy coatings that prevent water loss. Others, such as barnacles, close their shells tightly when exposed to air to minimize evaporation. Certain species of mussels and limpets secrete mucous to form a protective barrier around their bodies, which helps reduce water loss.
Moreover, intertidal organisms have adapted to withstand the mechanical stress caused by the crashing waves and the constant ebb and flow of tides. Mussels, barnacles, and seaweeds anchor themselves securely to rocks using strong adhesive substances to avoid being swept away. These organisms have also evolved to tolerate changes in salinity, as seawater salinity can fluctuate in the intertidal zone due to factors like rain, evaporation, or freshwater runoff.
In addition, some species can regulate their body temperature by moving between the warmer, exposed areas and cooler, submerged zones. This allows them to avoid overheating during high temperatures and freezing conditions during low tides.
The other options are not typical adaptations for intertidal zone organisms. Chemosynthesis (B) is more common in deep-sea environments, while temperature regulation (C) is more relevant for organisms in more stable environments. Extreme depths (D) are not relevant to the intertidal zone, as it is a shallow, coastal area.