Keith is an environmental scientist. He was studying the loss of ozone layer and its effect on different species. His data showed that in the beginning or twentieth century there were hardly any loss of ozone layer. He categorized that time period as time A. Further inquiry revealed that things didn't go well at the end of twentieth century - when there were severe loss of ozone layer. He categorized that time as time B. Which perion would more likely see ocean food webs disrupted, time A or time B? Hint: Unfortunately, the layer of good ozone is being destroyed by air pollution. The chief culprits are chlorine and bromine gases. They are released in aerosol sprays, coolants, and other products. Loss of ozone has created an ozone hole over Antarctica. Ozone depletion results in higher levels of UV radiation reaching Earth. In humans, this increases skin cancers and eye cataracts. It also disturbs the nitrogen cycle, kills plankton, and disrupts ocean food webs. The total loss of the ozone layer would be devastating to most life. Its rate of loss has slowed with restrictions on pollutants, but it is still at risk.
Ans: time B

Pete liked the human physiology so he started reading about the digestive system, especially about the jejunum. His colleague Fox, studied more about the stomach. Which student read more about the second part of the small intestine? Hint: The jejunum is the second part of the small intestine, where most nutrients are absorbed into the blood. As shown in Figure below , the mucous membrane lining the jejunum is covered with millions of microscopic, fingerlike projections called villi (singular, villus). Villi contain many capillaries, and nutrients pass from the villi into the bloodstream through the capillaries. Because there are so many villi, they greatly increase the surface area for absorption. In fact, they make the inner surface of the small intestine as large as a tennis court!
Ans: Pete

Hydrologists studied two samples of rain water. Jim studied an acid rain sample from a nearby city, and Dan studied a sample of water from another town. Which hydrologist learned less about the causes of acid rain formation? Hint: One result of air pollution is acid rain. Acid rain is precipitation with a low (acidic) pH. This rain can be very destructive to wildlife. When acid rain falls in forests, freshwater habitats, or soils, it can kill insects and aquatic life. It causes this damage because of its very low pH. Sulfur oxides and nitrogen oxides in the air both cause acid rain to form ( Figure below ). Sulfur oxides are chemicals that are released from coal-fired power plants. Nitrogen oxides are released from motor vehicle exhaust.
Ans: Dan

Two colleagues studied at the same university. Nick studied the brains of birds, while Joe studied the brains of mammals. Which colleague studied more about the mental abilities of an animal? Hint: The brains of all mammals have a unique layer of nerve cells covering the cerebrum. This layer is called the neocortex (the pink region of the brains in Figure above ). The neocortex plays an important role in many complex brain functions. In some mammals, such as rats, the neocortex is relatively smooth. In other mammals, especially humans, the neocortex has many folds. The folds increase the surface area of the neocortex. The larger this area is, the greater the mental abilities of an animal.
Ans: Joe