Problem: I can use this background: Protozoa generally feed by engulfing and digesting other organisms. As consumers, they have various roles in food chains and webs. Some are predators. They prey upon other single-celled organisms, such as bacteria. In fact, protozoa predators keep many bacterial populations under control. Other protozoa are herbivores. They graze on algae. Still others are decomposers. They consume dead organic matter. There are also parasitic protozoa that live in or on living hosts. For example, the protozoan that causes malaria lives inside a human host. Protozoa are also important food sources for many larger organisms, including insects and worms. Now, I have a new situation: George is investigating some algae that has recently started growing in his pond. He wants to find something ti prevent it from overtaking the pond as it makes it very hard to see under the water. After a bit of research he finds a protozoa that can help him. Answer this question please: Given the protozoa can successfully reduce the algae in the pond, is it a herbivore or a carnivore?

A: herbivore

Problem: I can use this background: The intentional cultivation of arthropods and other small animals for human food, referred to as minilivestock, is now emerging in animal husbandry as an ecologically sound concept. However, the greatest contribution of arthropods to human food supply is by pollination. Three-fourths of the world's flowering plants and about 35% of the world's food crops depend on animal pollinators to reproduce and increase crop yields. More than 3,500 species of native bees pollinate crops. Some scientists estimate that one out of every three bites of food we eat exists because of animal pollinators, including birds and bats and arthropods like bees, butterflies and moths, and beetles and other insects. Now, I have a new situation: Two villages had many inhabitants practicing horticulture. People from Valley village grew flowers and used arthropods and other insects for pollination and crop protection. Granite village used arthropods and snails, they cultivated them for food. Answer this question please: Which village used more butterflies and moths for pollination?

A: Valley

Problem: I can use this background: While the Grants were on the Galapagos, a drought occurred. As a result, fewer seeds were available for finches to eat. Birds with smaller beaks could crack open and eat only the smaller seeds. Birds with bigger beaks could crack and eat seeds of all sizes. As a result, many of the small-beaked birds died in the drought. Birds with bigger beaks survived and reproduced (see Figure below ). Within 2 years, the average beak size in the finch population increased. Evolution by natural selection had occurred. Now, I have a new situation: Two neighboring islands inhabited by thousands of birds each were hit by extreme weather. While Port island experienced wet weather over the past 3 summers, Bank island experienced severe drought, therefore the food supply on the island diminished. Answer this question please: Which island had more birds with bigger beaks survive?

A: Bank

Problem: I can use this background: Another major cause of extinction is global warming , which is also known as global climate change. During the past century, the Earth's average temperature has risen by almost 1C (about 1.3F). You may not think that is significant, but to organisms that live in the wild and are constantly adapting to their environments, any climate change can be hazardous. Recall that burning fossil fuels releases gasses into the atmosphere that warm the Earth. Our increased use of fossil fuels, such as coal and oil, is changing the Earth's climate. Any long-term change in the climate can destroy the habitat of a species. Even a brief change in climate may be too stressful for an organism to survive. For example, if the seas increase in temperature, even briefly, it may be too warm for certain types of fish to reproduce. Now, I have a new situation: Douglas is an inventor who creates a miniature engine in his backyard that he uses to power his house. In order to fuel his engine, he has to burn a large amount of fossil fuels every day. His neighbor, Elijah, on the other hand powers his house through wind turbines, and in the process doesn't burn any fossil fuels at all. Answer this question please: Who will contribute less to climate change?

A:
Elijah