<span>An example of an epithelial tissue where gases are exchanged is alveolar epithelium, which can be found in the lungs. This tissue is simple epithelial tissue. This is to be expected because the cell layer needs to be thin enough for the gasses like carbon dioxide and oxygen to diffuse or pass through. Stratified epithelial tissue contains several cell layers that would impair the exchange of gasses.</span>
I believe this question is trying to get you to realize the difference between acquired traits(one you get through doing something during life) and heritable traits(ones from Mom/Dad). For example, I really wish I was 6 foot 4... but the height trait comes genetically from your parents since it is coded in my DNA how tall I will be, therefore this trait must be passed down genetically and somewhere down the evolutionary tree the humans in the region which my family comes from was better off being short. An example that comes from acquired traits could be muscularity... my parents are both not very muscular but throughout my lifetime I enjoy working out and have become much more muscular, no matter how much your parents or grandparents lift weights YOU won't change so that change must be acquired through aging during your lifetime. Now the amount of muscle your body can put on is a heritable thing but that is beside the point. Hope this helps :)
True they are in the heart as well as the rest of your body
Answer: By studying the fossil record we can tell how long life has existed on Earth, and how different plants and animals are related to each other. Often we can work out how and where they lived, and use this information to find out about ancient environments. Fossils can tell us a lot about the past.
Artificial selection, also selective breeding occurs when humans breed individuals that have specific characteristics that they want to manipulate.
