A Level Biology Practice Exam

What defines tissue in biological terms?

1. a collection of cells that work together to perform a variety of functions

2. a grouping of differentiated cells with specialized functions

3. the basic unit of life capable of independent existence

4. a random collection of cells in a multicellular organism

The correct answer is: a grouping of differentiated cells with specialized functions

The correct choice highlights that tissue is a grouping of differentiated cells that are organized in a way that allows them to perform specialized functions. In biological contexts, tissues consist of similar cells that work in concert to fulfill particular roles such as providing structure, enabling communication, facilitating movement, or supporting other biological processes. Tissues are classified into four main types in animals: epithelial, connective, muscle, and nervous, each with distinct structures and functions that arise from the specialization of their constituent cells. This specialization is crucial for the organism's overall functionality and homeostasis, demonstrating the collaborative efforts of these cells. In contrast, other responses do not accurately represent the definition of biological tissue. For instance, while a collection of cells is indeed part of the tissue structure, it is the differentiation and functional roles of those cells that truly define tissue. The basic unit of life refers to cells themselves, not the groups they form. Lastly, a random collection of cells does not capture the organized and functional nature that defines what a tissue is.