Question: I have a new situation: An island in the Pacific ocean has a strange an compact ecosystem. There are only 4 species of living organism on it. There are plants, Insects, birds, cats. Because of this there is a very specific food chain on this island. Any new species added to it has cause the population of all other species to decrease. This is because when a new species is added it causes the others to not have enough food as they all feed on each other. The insects eat the plants, the birds eat the insects and the cats eat the birds. When a species of wolf that eats the cats was added the plants began to die off because the wolves outlived the cats so the plants could not get the energy in time to regrow before the insects would eat them. Because of this the insects would die, then the birds then the cats. because the energy source for each species was being consumed faster than it could be produced. But I can use this background: Energy is passed up a food chain or web from lower to higher trophic levels. However, only about 10 percent of the energy at one level is passed up the next level. This is represented by the ecological pyramid in Figure below . The other 90 percent of energy at each trophic level is used for metabolic processes or given off to the environment as heat. This loss of energy explains why there are rarely more than four trophic levels in a food chain or web. There isn't enough energy left to support additional levels. It also explains why ecosystems need a constant input of energy. What is an answer for this question: which part of the food chain will be hurt first if a new species is added that eats insects, the bird population or the plants?
Answer: birds

Question: I have a new situation: The underwater fishing teams picked their spots early. Team Bob went at the mouth of the river, where the freshwater met the salty seawater in the hope that more turbidity from the river and more nutrients will attract more fish. Team Dan went south where they knew there was less of a thermocline, so they could catch fish without taking risks. But I can use this background: Thermoclines, or sudden changes in temperature. Where the air temperature is higher than the water temperature, shallow water may be warmed by the air and the sunlight but deeper water remains cold resulting in a lowering of temperature as the diver descends. This temperature change may be concentrated over a small vertical interval, when it is called a thermocline.[3][4] Where cold, fresh water enters a warmer sea the fresh water may float over the denser saline water, so the temperature rises as the diver descends.[3] In lakes exposed to geothermal activity, the temperature of the deeper water may be warmer than the surface water. This will usually lead to convection currents.[3] What is an answer for this question: Which team had more chances to catch fish?
Answer: Bob

Question: I have a new situation: Keith is a zoologist. He studies large predators. Last year, he was studying different species of lions. First, he visited the Gir forest in India. There he found the Asiatic Lions. Unfortunately, only few Asiatic Lions are left in the wild, and they have to mate with their close relatives. He then visited the Serengeti reserve in Tanzania. There he found that the African Lions were not forced to mate with close relatives due to their large number. But I can use this background: During sexual reproduction, mating with a close relative (inbreeding) often leads to inbreeding depression. Inbreeding depression is considered to be largely due to expression of deleterious recessive mutations. The effects of inbreeding have been studied in many vertebrate species. What is an answer for this question: Would Serengeti reserve see less or more inbreeding depression than Gir forest?
Answer:
less