Which of the following describes R-selected species?

R-selected species are characterized by their strategy of producing a large number of offspring in a relatively short period. This reproductive strategy is advantageous in unstable or unpredictable environments where the survival rate of offspring may be low. R-selected species typically have smaller body sizes and shorter lifespans, enabling them to mature quickly and reproduce early, thus maximizing their reproductive output.

The focus on producing many offspring means that these species allocate less energy and resources to parental care, in contrast to species that invest heavily in fewer offspring. Examples of R-selected species often include insects such as flies or plants like dandelions.

The description involving semelparity, or a one-time reproductive event in a lifetime, aligns with certain R-selected species but is not the defining feature compared to the emphasis on quantity and rapid succession of generations. The highlights of small body size, fast-paced life cycles, and high offspring numbers encapsulate the essence of the R-selection strategy.