CourseCourseConceptConceptDocumentDocument

AP Biology 8.1 B Explain How the Behavioral Responses of Organisms Affect Their Overall Fitness and May Contribute to the Success Questions

Practise AP Biology 8.1.B questions by connecting communication and behavioral responses with survival, reproductive success and population fitness.

Syllabus
Effective Fall 2025
Course
AP Biology

Exam points

  • explain how visual, audible, tactile, electrical or chemical signals change the behavior of other organisms
  • connect innate, learned and cooperative behaviors with survival, reproductive success and individual fitness
  • use behavioral data to infer signaling effects, selection pressures and consequences for population success

AP Biology 8.1 B Explain How the Behavioral Responses of Organisms Affect Their Overall Fitness and May Contribute to the Success Questions question 1

[Maximum number: 1]

Many insects rely on pheromones (chemical signals) that are released by the females to find mating partners. Scientists hypothesize that, in a certain type of moth, the behavior of male moths in response to pheromones is regulated by the extracellular signaling molecule 20E.

To investigate whether the binding of 20E to its receptor, DopEcR, affects behavior in moths, scientists injected male moths with saline (control solution) or with small interfering RNA molecules (siRNAs) that inhibit the expression of the gene encoding DopEcR. The scientists then exposed the moths to the pheromone and determined the percent of total time observed that the moths engaged in general activity, defined as movement in any direction. The scientists also determined the percent of the general activity time that the moths spent in oriented activity, defined as movement toward an area of high pheromone concentration (Table 1).

Table 1. Average General and Oriented Activity in Male Moths Injected With Saline or siRNA Molecules

Table 1. Average General and Oriented Activity in Male Moths Injected With Saline or siRNA Molecules

DopEcR is a G protein-coupled receptor. When 20E binds to DopEcR, GTP displaces the GDP bound to the G protein, and a signaling pathway is activated. The scientists hypothesize that this leads to the transcription of genes associated with the oriented activity observed in the male moths (Figure 1).

Figure 1. A simplified model of a signaling pathway activated by the binding of 20E to its receptor, DopEcR

Figure 1. A simplified model of a signaling pathway activated by the binding of 20E to its receptor, DopEcR

D.

Use evidence from the information provided to support the scientists' claim.

All question bank results loaded