Which of the following would be produced by meiosis?

red blood cell
cells of the stem in plants
sperm cell
epithelial cell

What are two reasons for why a species might disappear from the fossil record?

Over the past 60 years, many amphibian species have experienced significant population declines and some species have become extinct. scientists suspected that local human activities such as the destruction of wetlands, regional pollution, and deforestation were the main reasons for these losses. however, research over the past 20 years reveals significant amphibian population declines in protected areas of the world, such as nature preserves and parks. these global declines suggest widespread problems including increased ultraviolet radiation, acid rain, and disease. in switzerland, for example, 14 of the 20 native amphibian species are threatened with extinction. chytridiomycosis is a fungal disease first identified in 1998 as a cause of massive amphibian deaths. in some severely impacted populations, a few individuals have survived, perhaps because of some natural resistance. if these resistant individuals continue to survive and prosper, new resistant populations might emerge. this would be an example of the founder effect artificial selection genetic drift natural selection sexual selection

One important development during the 3rd trimester that will insulate the infant against changes in temperature is a. the deposition of fat under the skin b. the closing of the septum between c. the atria of the heart d. the beginnings of lung functioning e. the beginnings of light and sound sensing