Why do women have periods? TedTalk Video Check 1. Each time ovulation does not result in a healthy pregnancy, what happens inside the uterus? Be descriptive.

9. Define chromatin.

20. Sketch and label a centrosome with two centrioles.

16. Monroe uses a microscope to observe specimens in science class. The microscope enlarges objects to 100 times their actual size. Find the size of each specimen as seen in the microscope.

In animal cells, the assembly of spindle microtubules starts at the centrosome. What is another name for the centrosome?

1. What is a macromolecule? Identify the four types of biological macromolecules. 2. Describe the function of carbohydrates in your body.