Which effect does the sun's energy have on a comet? A. It causes the comet to form a bright tail.
B. It causes the core of the comet to melt.
C. It causes the comet to turn toward earth.
D. It causes the comet to break apart.

Study the diagram of a cell. which structure is found only in plant cells and functions in the process of photosynthesis? w x y z

What is the goal of cellular respiration

Embryonic stem cells are cells derived from an embryo. these cells can be used to create new tissues for patients suffering from certain illnesses and disorders. which statement best summarizes why the use of embryonic stem cells could be seen as unethical? a. some people consider embryos to possess rights equal to those of fully developed human beings. b. extracting stem cells from embryos is a very energy-intensive process, which consumes resources that could be used elsewhere. c. embryos are difficult to obtain, so the monetary cost of using them for research outweighs their benefit. d. the process of extracting stem cells from embryos generates biohazardous waste that cannot be safely disposed of.