The answer is a the first one.
Summarize how the overharvesting of a single species, such as a baleen whale, can affect an entire ecosystem. Overharvesting the baleen whale would affect the entire ecosystem by changing the relationships among the organisms in the food web.
Answer:
Only options a reflects the instances with valid experiment or conclusion.
Quality of any experiment depends upon two things reliability and validity. Reliability is measure of regeneration of results every time an experiment is performed under specific conditions.
Validity is measure of accuracy of results of an experiment. It can be check by two ways: internal validity (checks the design of the experiment) and external validity (checks if the conclusion is the real explanation of the phenomenon).
Now, in marine biologist experiment, he concluded the results only after one breeding season. This makes his results unreliable as it might have happened by chance.
Similarly, in cola experiment the taste was only checked by one candidate i.e. Karl. He might have problem in his taste buds. In addition, the temperature of cola can also affects its taste which is not taken care of in the experiment. Hence, it is not the valid experiment.
Similarly. Jeanette could use more plants for her experiment and Robert just followed only one instruction. He didn't perform any experiment.
Answer:
Predation.
Explanation:
Limiting factor refer to resources or environmental condition that limit the growth or distribution of organisms in the ecosystem. This make the organism not to occupy their original niche. Predation is a limiting factor. Predation refer to ability of an organism to prey on another organism or capture it. Predation is a density dependent factor whose effect on population determined the total size of the population. Fox chasing pika is an example of predation.