Bio 14 Lab Report

In the BIO 14 Lab, the organismal system used for the last of three labs this semester is the Mimosa pudica plant. In these three weeks the stimulus-response of these plants will used to conduct experiments on the phenotypic plasticity of Mimosa pudica. Phenotypic plasticity is the ability of an organism to change its phenotypic traits in response to changes in the environment. And while very beneficial in some ways such as by allowing organisms to adapt to a changing environment quickly, it also has its costs. The greatest cost probably comes in the energy the organism needs to expend in order to produce the changed trait. For example, in the phototropic effect in plants, the plant bends toward the sunlight to allow for more of its leaves to get direct
Two important aspect that these plants would need to consider is the availability of water as well as the exposure to sunlight. In addition to phototropism, already discussed, plants have multiple ways that they can change their stimulus-response due to dehydration. Plants with only limited access to water may experience changes such as growing leaves with smaller surface area (less area for photosynthesis, but also less area for water loss), dropping of the larger lower leaves, and may also experience direct root growth into deeper soil for an increased water supply. Information about knowing where their predators would also be important as it would tell the plants that they need to execute a strong stimulus response that limits the potential danger. Thus heavy touches (heavy pressure) and other strong stimuli that indicate that predators are near would be reacted to by the plants. However, smaller constant stimuli, such as some mildly strong wind gusts and/or rain (depending on the plant’s native habitat), would probably be ignored as the plant may have also habituated to these frequent