Explain each of these familiar phenomena in terms of what you learned in this chapter: a. pimples, b. dandruff, c. greasy hair and 'shiny nose,' d. stretch marks from gaining weight, e. freckles.

Video transcript

Hello everyone and welcome to today's video. So which of the following are examples of local accumulation of Melanie as answer choice A we have freckles, B, pimples, C pigmented and D both A and C. Well, let's go over each of these answer choices beginning by answer choice B, we have pimples while these pimples are not going to be a result of a local accumulation of these pigment melanin and why? Well, these pimples are usually going to come as a result of other factors such as the accumulation of external substances or just changes in hormones due to puberty and things as such. And therefore we're going to cancel them out. Then we have eight which is freckles. Well, these freckles are going to be these small brown spots that develop uncertain. So sun exposed areas of the skin. Now these freckles are going to develop because remember that Melaine is used to protect ourselves against you the radiation. So in these areas that we were exposed to just sun rays to U V radiation, we may develop freckles due to overproduction of melanin. Therefore, this is a correct answer choice and we're not going to cancel it out. Then we have see which states pigmented. Now these are going to be what we call. And these are another example of local accumulation of melanin. These are going to be clusters of melanocytes which are going to be the molecules or choose the cells are going to be producing melanin. And these are going to be coming up again as a result of just an excessive production of melanin. This is why we have moles resulting in dark spots or bumps in the skin also known as moles. Now, this is also coming or is an example of the local accumulation of melanin and therefore, we cannot cancel it out since we were not able to cancel out either A or C, the correct answer is going to be D both A and C. I really hope this video helped you and I hope to see you on the next one.