Which two of the following are MAIN ideas of the article? 1. Carbon shifts from one area to others through the slow and fast carbon cycles. 2. When the ocean takes in more carbon than it releases, it becomes more acidic. 3. Rain breaks down rocks, which are eventually brought to the ocean. 4. Human behavior has led to increased carbon levels in the atmosphere.

What will happen to a population of predators if there is a sudden, temporary increase in the number of prey? a. the population of predators will be uniform with no change. b. the population of predators will increase first and then decrease slowly. c. the population of predators will increase continuously.

Which of the following cell structures is significantly different between gram- positive and gram-negative bacteria?

Monarch butterflies have brightly colored orange wings with black patterns on them, making them easily visible to birds that eat butterflies and moths, yet birds rarely eat the monarchs. likewise, the monarch caterpillars are brightly striped yellow and white and black, and they also are rarely eaten by birds, although some wasps will attack them and feed them to their young. what can be inferred from these observations? monarchs must threaten and attack birds, but not wasps. monarchs have a way of discouraging bird predation that does not involve hiding. monarchs’ wings are so colorful that most birds must find them difficult to eat. monarchs lay more eggs than other less conspicuous butterflies.