Multiple choice

1. An element that speeds up chemical reactions is called a/an

A. enzyme. 

B. calorie. 

C. substrate.

D. solvent.

2. A substance that’s attracted to water molecules is called

A. hydrophobic. 

B. cohesive.  

C. hydrophilic.

D. adhesive.

3. Short, hairlike projections called _______ enable the motion of some eukaryotic cells.

A. cilia 

B. actinites 

C. centrioles

D. microtubules

4. Biology is the study of

A. animals. 

B. the physical world. 

C. plants.

D. life.