Which structure is the site of nutrient and gas exchange between the mother and a growing fetus? A. placenta B. umbilical cord C. fallopian tube D. uterus

Which choice describes a community? The desert A hole in which snakes lives A forest of birds, insects, and squirrels A desert of sand, rocks, hawks and snakes

Why is it good for aquatic organisms that live in cold climates that ice floats?

Amylase catalyzes the breakdown of carbohydrates and is present in saliva. Pepsin is an enzyme that breaks down proteins in the stomach. When amylase reaches the stomach it no longer functions. Why?

Which of the following planetary objects has the most affect on Earth's tides? moon sun Mars Venus

Describe the life cycle of a virus.

What process do the arrows for oxygen going in and water coming out represent in the Figure 9-2 diagram of the mitochondria?

Sponges are made up off

The maxinmum numbers of individuals of a particular species that a partiticlar environment can support is its

What is the layer of the atmosphere 20 km above Earth's surface

An experiment was conducted to determine which type of fruit attracts the most fruit flies. Equal sized pieces of apple, pear, and banana were placed in separate containers at different areas around the school.