What happens to a cell in the S phase?

A. The nuclear envelope develops around each set of chromosomes.

B. DNA replicates to form two copies of chromosomes.

C. Sister chromatids separate out from the chromosomes.

The walls of lymphatic capillaries are composed of endothelium. Fluid flows in one direction in lymphatic capillaries. Lymphatic capillaries are dead-end tubes. Lymphatic capillaries are highly permeable.

Why is a hypothesis important to a scientific investigation? A) Without a hypothesis, there is no way to tell if you did an experiment correctly B) Without a hypothesis, there is no way to tell if you have done enough research about the problem.

1. Can bacteria or viruses be seen with the naked eye?

What organelle controls a cell's activities?

Suppose that an arginine residue in the active site of an enzyme was mutated to alanine. As expected, the alanine mutant was inactive, suggesting that the arginine residue was critical to the catalytic mechanism.

Suppose you want to set up an experiment to test the hypothesis that electromagnetic fields cause CCD, and you have 6 hives to work with. Which of these is the best experimental setup? A. 6 hives exposed to high levels of EMF B.

Which transports digested lipids and bile across digestive fluids to the surface of mucosal cells? a. LDL'sb. micellesc. HDL'sd. chylomicrons

Which biomes contain a limnetic zone surrounded by a littoral zone? A. rivers and streams B. estuaries C. coral reefs D. ponds and lakes E. oceans

QUICK! In a developing embryo, what process allows cells of the mesoderm to give rise to muscle, bone, and heart tissues? Select one: a. cell differentiation b. cell depolarization c. cellular respiration d. cellular replication

According to the fluid mosaic model of the cell membrane, a. there are fats floating in the protein layer. b. carbohydrates function as membrane channels. c. nonpolar ends of phospholipids are exposed to water inside and outside the cell. d.