Clonal selection is the division of _____ that have been stimulated by binding to an antigen, which results in the production of cloned _____.

What acid is responsible for stomach acidity?

The atrioventricular valves are indicated by which numbers?    

In humans, most nutrient molecules are absorbed by the _____.  

How is the stomach lining protected from the strongly acidic pH of its contents?

What type of epithelium would you expect to find covering a surface subject to physical forces?

From the pulmonary veins, blood flows to the _____.

_____ muscle moves the bones.

Vertebrate immune cells, which are phagocytic, include ________.  I) neutrophils II) macrophages III) dendritic cells IV) natural killer cells

The matrix of blood tissue, where water, salts, and dissolved proteins are found, is _____.