Natural selection is best described as the survival of:

Evolution by natural selection says that change occurs in:

Evolution by natural selection cannot occur without the introduction of new traits through:

Traits that help an organism survive in its environment are called:

Which of the following is the body's system for protection and maintaining homeostasis?

Foreign substances that pose a threat to the body are called:

Which of the following may be a harmful antigen?

Bacteria are types of ________ cells.

When harmful foreign substances enter the body, the immune system responds by producing _______ to fight the invaders.

What type of cells are responsible for producing the antibodies that fight away infections?

When the body produces antibodies to fight dangerous antigens, this is what type of immunity?

Antibodies may be passed from a mother to her newborn through her breastmilk, building up the immune system of the baby. This type of immunity is called:

Vaccinations may be used to immunize against certain diseases. What type of immunity does this exhibit?

Medicines that are engineered to destroy bacteria are called:

Medicines that are engineered to destroy viruses, such as the influenza virus, are called:

What type of antigens are shown in this image?

A population of bacteria is treated with an antibiotic; however, a few remaining bacteria survive. How did this antibiotic resistance occur?

Chemicals that are sprayed onto crops to kill insects or other organisms that would destroy the crop may be called:

A farmer sprays his fields with a pesticide to remove insects and worms that have been eating away at the crop. Some of the pests survive and continue to plague the crop. What caused this?