Living Environment Regents Practice Test

How can single-celled organisms maintain homeostasis despite lacking complex structures?

1. By undergoing photosynthesis

2. Through cellular cooperation

3. By absorbing nutrients from their environment

4. Through genetic mutations

The correct answer is: Through cellular cooperation

The ability of single-celled organisms to maintain homeostasis without complex structures primarily relies on their intrinsic capabilities to respond to environmental changes effectively. Cellular cooperation can occur in some microbial communities, where different types of cells communicate and coordinate their activities to adapt to external conditions. However, for most single-celled organisms, their ability to regulate their internal environment is largely due to their structural and functional features. These organisms possess cell membranes that regulate the movement of substances in and out of the cell, allowing them to control their internal temperature, pH, and nutrient concentrations. Through processes like osmosis and diffusion, they can exchange materials with their surroundings to achieve balance, ensuring their survival in varying conditions. The options of photosynthesis, nutrient absorption, and genetic mutations, while relevant to some organisms, do not directly address the general capacity of single-celled organisms to maintain homeostasis on their own. Photosynthesis specifically refers to energy production in certain organisms like plants and some bacteria, rather than the broader concept of homeostasis. Nutrient absorption is a function of metabolism and does not encompass the full range of required mechanisms for homeostasis. Genetic mutations may alter an organism’s traits but are not a direct process for maintaining stable internal conditions. Thus, the adaptability through cellular mechanisms