Here we have a pretty straightforward example problem asking, which of the following statements about erythrocytes is false? And we've got these 4 potential answer options down below. Option A says they use mitochondria to make their own ATP. B says they are smaller than the average body cell. C says their shape is flexible, and D says they don't have a nucleus. Now, of course, recall from our last lesson video that erythrocytes, or red blood cells, lack a nucleus and many organelles, including mitochondria. And so erythrocytes don't have mitochondria, and to say that they use mitochondria to make their own ATP is simply a false statement. Again, because they don't have mitochondria, and so they have to use other means to make their own ATP.

And so what this means is that answer option A is the false statement that we are looking for. So we can indicate that A here is the correct answer to this problem, and these other statements that we see down below are all true statements. It's true that erythrocytes are smaller than the average body cell. In fact, they're about 3 times smaller than the average body cell, which is pretty significant. It's also true that their shape is flexible. They have a biconcave shape that increases their flexibility. They lack a nucleus and many organelles, which also adds to their flexibility since that helps them be able to bend and fold easier. They also have proteins such as spectrin, which increases their flexibility and helps them maintain their shape even after they have to fold and bend through tiny blood vessels and capillaries, and when they get back into a larger space, they can spring back into their original shape because of those proteins.

Also, erythrocytes don't have a nucleus, and so they are considered anucleate. So again, option A is the correct answer to this problem. Now it is interesting to think, what if erythrocytes did have mitochondria? Well, recall from previous videos that mitochondria use or consume oxygen to make ATP. And erythrocytes play a huge role in delivering oxygen to tissues. And so if erythrocytes did have mitochondria, they would be consuming some of the oxygen that they were supposed to be delivering to the tissues, and so that would be similar to a pizza delivery guy taking a bite out of one of the slices before they deliver it to you. It's simply not going to work, and so thankfully, our erythrocytes have evolved to dispose of their mitochondria. And so again, this concludes this problem. Option A is the correct answer, and I will see you all in our next video.