Of what economic importance are earthworms?

A snail shell is quite different from the familiar bony skeleton of a mammal. In what ways does a shell function as a skeleton?

a. What features of squid and octopuses are adaptations for predation? b. Do all of the tentacles of a squid have suckers? c. What are some functions of suckers? d. Find the mouth at the base of the tentacles. What is the shape and consistency of the jaws? You may need to make an incision to expose the mouth and jaws. e. Why are sensory organs more prominent in cephalopods than in other classes of mollusks? f. Consider objective 1 listed at the beginning of this exercise. In what ways are image-forming eyes significant to fundamental processes for cephalopods?

Mollusks exhibit a variety of feeding methods. List at least four and discuss adaptations and examples for each type.

a. How does the foot of a bivalve differ from that of snails or chitons? b. How could predators attack an animal closed "tight as a clam"? c. Is immobility a problem for filter feeders such as oysters? Why or why not?

a. What is the texture of the mantle of Anodonta? b. Are siphons in Anodonta as obvious as they are in figure 38.8? c. Consider objective 1 listed at the beginning of this exercise. In what ways would a shell contribute to the survival and reproductive success of mollusks in their environment?

Identify the two events described in the study. Do the results indicate that the events are independent or dependent? Explain your reasoning. A study found that there is no relationship between being around cell phones and developing cancer.

Draw two normal curves that have the same mean but different standard deviations. Describe the similarities and differences.

Draw two normal curves that have different means but the same standard deviation. Describe the similarities and differences.

Homework: Homework 4 (H4)
Use the probability distribution to complete parts (a) and (b) below The number of school related extracurricular activities per student Activities: 0, 1, 2, 3, 4, 5, 6, 7 Probability: 0.059, 0.122, 0.162, 0.179, 0.216, 0.126, 0.084, 0.052 (a) Find the mean, variance and standard deviation of the probability distribution.

What structures are found in plant cells that are not found in animals cells?

Explain the relationship between variance and standard deviation. Can either of these measures be negative? Explain.

Determine whether the statement is true or false. If it is false, rewrite it as a true statement. When each data class has the same frequency, the distribution is symmetric.

A misleading graph is a statistical graph that is not drawn appropriately. This type of graph can misrepresent data and lead to false conclusions. (a) explain why the graph is misleading, and (b) redraw the graph so that it is not misleading

U.S. Crude Oil Imports by 1st quarter Country of Origin 2008