PSB 4504 Final Study Guide (103 Questions with Correct Answers)

PSB 4504 Final Study Guide (103 Questions with Correct Answers) Developmental plasticity: - CORRECT ANSWER When phenotypic plasticity is seen in embryonic or larval stages of animals or plants. Reaction norms: - CORRECT ANSWER The potential to generate an almost infinite number of small variations in phenotype in response to environmental cues. Examples include muscle hypertrophy in people and the wood frog tadpoles' response to predators. Polyphenism: - CORRECT ANSWER Refers to discontinuous (either/or) phenotypes elicited by the environment. An example includes turtles that will develop into males or females based on the temperature of the environment. Density-induced polyphenism: - CORRECT ANSWER seen in the desert locust, they can be green, solitary, and with short wings, or have long wings, bright colors, and be gregarious. If they are crowded they will molt into the gregarious type. Seasonal change polyphenism: - CORRECT ANSWER seen in some butterfly species have different phenotypes depending on when they develop in the pupa. Some are in the pupa by summer and some by spring. Since darker pigment absorbs sunlight better, spring butterflies are darker. Photoperiod polyphenism: - CORRECT ANSWER Mammals that live in environments covered in snow also change color. In summer they are brown or gray, and in winter they are white. Direct transcriptional regulation: - CORRECT ANSWER modifying DNA regions Neuroendocrine system: - CORRECT ANSWER hormonal changes that may change the expression of genes Direct induction: - CORRECT ANSWER direct interaction with the cell to alter gene expression Promoters: - CORRECT ANSWER indicates where RNA polymerase begins transcription. Not accessible until enhancers bind transcription factors that affect nucleosomes. RNA polymerase: - CORRECT ANSWER unwinds DNA double helix and begins the synthesis of nuclear RNA