Marsupials, such as kangaroos and koala bears, are mammals. humans are mammals, too. however, there are differences between marsupials and humans. for instance, the average baby human is born after spending 38-40 weeks inside of its mother, but baby marsupials are born after only 4-5 weeks. what feature does a marsupial possess that allows babies to be born earlier? a. an egg sac b. a pouch c. fur d. a uterus

At which location in earth’s interior does the top density continue to increase as thickness decreases?

In what part of the body does the most muscle activity happen?

Female luna moths (actias luna) attract males by emitting chemical signals that spread through the air. a male hundreds of meters away can detect these molecules and fly toward their source. the sensory organs responsible for this behavior are the comblike antennae visible in the photograph shown here. each filament of an antenna is equipped with thousands of receptor cells that detect the sex attractant. based on what you learned in this chapter, propose a hypothesis to account for the ability of the male moth to detect a specific molecule in the presence of many other molecules in the air. what predictions does your hypothesis make? design an experiment to test one of these predictions.