Selective pressure Knowledge-Based Download PDF

Questions

1. 1.

   Under which circumstance will a persistent selective pressure fail to produce an evolutionary change in a population over successive generations?

   • A) The selective agent driving differential mortality is abiotic rather than biotic.
   • B) The phenotypic variation affecting survival has no underlying heritable genetic basis.
   • C) The intensity of the selective pressure remains completely constant over time.
   • D) The population is sufficiently large to minimize the impact of random genetic drift.
2. 2.

   Which of the following describes how an environmental selective pressure interacts with genetic variation in a population?

   • A) It stimulates individuals to generate targeted beneficial mutations in response to environmental demands.
   • B) It eliminates all phenotypic differences to maintain uniform survival across the entire population.
   • C) It actively converts non-adaptive alleles into advantageous forms during an organism's lifetime.
   • D) It sorts existing phenotypic diversity by favoring the differential survival and reproduction of certain variants.
3. 3.

   A persistent drop in average winter temperatures over several decades acts as a selective pressure on a mammal population with variable fur density. What is the direct evolutionary outcome of this selective pressure on the population?

   • A) The colder temperature induces targeted mutations that produce thicker fur in developing embryos.
   • B) Individual mammals develop thicker fur in response to the cold and transmit this acquired trait to their offspring.
   • C) Individuals with phenotypes conferring denser fur experience greater reproductive success, increasing the frequency of those alleles over time.
   • D) The environmental stress eliminates all genetic variation in the population within a single generation.
4. 4.

   Which of the following scenarios represents a biotic selective pressure influencing the evolution of a population?

   • A) An increase in predatory bird abundance that favors camouflage coloration in moths
   • B) A decrease in annual rainfall that favors plants with deeper root systems
   • C) A rise in average ocean temperature that favors heat-tolerant coral symbionts
   • D) An elevated level of soil salinity that limits seed germination to salt-tolerant grasses
5. 5.

   Which of the following statements best describes the role of a selective pressure in natural selection?

   • A) It actively induces purposeful genetic mutations in individuals striving to adapt to changing conditions.
   • B) It ensures that all individuals within a population achieve identical reproductive fitness over successive generations.
   • C) It completely eliminates genetic variation by causing all non-advantageous alleles to disappear immediately in a single generation.
   • D) It exerts an environmental force that results in differential survival and reproduction among individuals based on their heritable traits.