Questions: Natural selection produces change in - populations over a single breeding cycle, as advantageous traits affect the supply of environmental resources of different individuals. populations over multiple breeding cycles, as mutations affect the reproductive fitness of different individuals. individuals during their lifespan, as developmental chanoen affect the phenotypes of each member of a population. Individuals during their reproductive years, as hormonal imbalances affect the genotypes of each member of a population.

The answer is the second one: populations over multiple breeding cycles, as mutations affect the reproductive fitness of different individuals.

Explanation for each option:

1. Populations over a single breeding cycle, as advantageous traits affect the supply of environmental resources of different individuals.

   • This option is incorrect because natural selection typically requires multiple generations to produce significant changes in a population. A single breeding cycle is usually insufficient for noticeable evolutionary change.

2. Populations over multiple breeding cycles, as mutations affect the reproductive fitness of different individuals.

   • This option is correct. Natural selection acts on variations within a population, which can be caused by mutations. Over multiple breeding cycles, individuals with advantageous traits are more likely to survive and reproduce, passing those traits on to future generations, thereby changing the population over time.

3. Individuals during their lifespan, as developmental changes affect the phenotypes of each member of a population.

   • This option is incorrect because natural selection does not act on individuals during their lifespan in a way that changes their genetic makeup. It acts on the population level over generations, not on individual development.

4. Individuals during their reproductive years, as hormonal imbalances affect the genotypes of each member of a population.

   • This option is incorrect because hormonal imbalances do not change an individual's genotype. Natural selection involves changes in allele frequencies in a population over time, not changes in individual genotypes due to hormonal factors.

In summary, natural selection leads to changes in populations over multiple breeding cycles by affecting the reproductive success of individuals with different genetic traits.