3.5.4 Test 3. The diagram below shows how proteins are assembled by ribosomes. A substance called tRNA delivers molecules, and a substance called mRNA provides the ribosome with the sequence in which the molecules would be connected in order to build each protein. Based on your knowledge of protein synthesis, what type of molecule is labeled "X" in the diagram?

An ecologist studied the same species of deer during the summer and the winter. she noticed that during the summer, when there was plenty of food, the deer were energetic and playful. however, during winter when food was scarce, the deer moved more slowly and did not run unless they needed to escape a predator. which scientific fact is best supported by her observations?

Which of the following is the earliest era of earth's geologic time scale? cenozoic mesozoic precambrian paleozoic

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.