The cells called perform photosynthesis and cellular respiration.
1. they are the most abundant type of cell in a typical plant body.
2. the cells called die as they mature, forming a rigid skeleton that support a growing plant.
3. are long, thin water-conducting cells with tapered ends.
4. are short, wide water-conducting cells.
5. food-conducting cells called are arranged end-to-end in phloem tissue.

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

Which of the following produces carbon dioxide? a. plants b. animals c. decomposers d. all of the above

After a group of researchers conducts a new experiment that has never been conducted before, what is the best way for other scientists to make sure that the data is real