Question: In the U.S., the majority of electricity is produced by burning coal or other fossil fuels. This causes air pollution that harms the health of living things. The air pollution also causes acid rain and contributes to global warming. In addition, fossil fuels are nonrenewable resources, so if we keep using them, they will eventually run out. The main advantage of nuclear energy is that it doesn’t release air pollution or cause the other environmental problems associated with the burning of fossil fuels. On the other other hand, radioactive elements are nonrenewable like fossil fuels and could eventually be used up.  Thorn county used fossil fuels for their energy needs, while Plant county used nuclear power. They both polluted the environment in different ways.  Which county released less air pollution?
Answer: Plant

Question: Scientists think that the earliest flowers attracted insects and other animals, which spread pollen from flower to flower. This greatly increased the efficiency of fertilization over wind-spread pollen, which might or might not actually land on another flower. To take better advantage of this “animal labor,” plants evolved traits such as brightly colored petals to attract pollinators. In exchange for pollination, flowers gave the pollinators nectar.  Last week, John visited the national park near his city. He saw many flowers. His guide explained him that there are two categories of flowers, category A and category B. Category A flowers spread pollen via wind, and category B flowers spread pollen via animals.  Would category B flower have more or less colorful petals than category A flower?
Answer: more

Question: As a cell grows, its volume increases more quickly than its surface area. If a cell was to get very large, the small surface area would not allow enough nutrients to enter the cell quickly enough for the cell’s needs. This idea is explained in Figure below . However, large cells have a way of dealing with some size challenges. Big cells, such as some white blood cells, often grow more nuclei so that they can supply enough proteins and RNA for the cell’s requirements. Large, metabolically active cells often have lots of cell protrusions, resulting in many folds throughout the membrane. These folds increase the surface area available for transport of materials into or out of the cell. Such cell types are found lining your small intestine, where they absorb nutrients from your food through protrusions called microvilli .  There are two cells inside a Petri dish in a laboratory, cell X and cell Z. These cells are from the same organism, but have different characteristics. For example, cell Z is smaller than cell X. Furthermore, scientists studying the two cells have recorded that cell X is more metabolically active than cell Z.  Which cell will have more folds throughout the membrane?
Answer:
cell X