So here we have an example problem that says, imagine you're a farmer and a surge in the Colorado potato beetle population has taken its toll on your potato crops. Using the information in the food chain below, how could you go about reducing the Colorado potato beetle population while keeping your potato crops healthy? And so notice that again down below we've got this food chain that starts on the far left with the potatoes that you're trying to grow and keep healthy as a farmer. Now these potatoes are being eaten by Colorado potato beetles, which, again, is creating the problem for your potatoes. Now the Colorado potato beetle is eaten by ground beetles, and ground beetles are eaten by northern cardinals.
Now keeping this in mind, option a says remove all the potato crops to exert bottom up control on the Colorado potato beetle population. But as a potato farmer, you don't want to remove all of your potato crops. You're trying to keep your potato crops healthy so that you can sell your potatoes. So removing all of the potato crops is not going to be the best option here. So let's eliminate answer option a.
Now, moving on, option b says, introduce Northern Cardinals to the farm to exert top down control. Now, notice the Northern Cardinals are here. Now, if we introduce northern cardinals, that means its population size will increase, which we can indicate with an up arrow. That means there will be more northern cardinals to eat the ground beetles. That means that the ground beetles will go down.
And if the ground beetles go down, that means that there's less ground beetles to eat the Colorado potato beetle. And that means the Colorado potato beetles will go up and they will continue to eat more and more of your potatoes and it will be a disaster. So answer option b is not going to be the correct answer either. Now notice answer option c says, introduce ground beetles to the farm to exert top down control. Now if we introduce ground beetles, its population size will go up.
Then it will eat more of the Colorado potato beetle, so its population size will go down, and there will be less Colorado potato beetles to eat your potatoes, and so you can grow healthy potato crops. So this means that answer option c is the correct answer to this example problem. So we can go ahead and indicate that's the case. Now just in case, notice option d says, remove ground beetles from the farm to exert top down control on the Colorado potato beetles. Now again, if you remove ground beetles, its population will go down.
There will be less of them to eat the Colorado potato beetle, so its population goes up, and then there will be more Colorado potato beetles to eat your potatoes. And, again, that's not what you want, so option d is not correct. So again, option c is the correct answer to this example, and I'll see you all in our next video.