6. Which one is false about a cell membrane?
(A) a rigid structure；
(B) a bilayered structure；
(C) composed of phospholipid molecules；
(D) a fluid structure.

2. In our diets, glucose is often covalently bonded with others in the polymer form of __ (A) a polysaccharide；(B) a fatty acid chain；(C) a triglyceride；(D) a simple sugar.

3. In living cells, a process by which cells break polymers down into monomers by breaking covalent bonds is called? (A) hydrolysis；(B) dehydration synthesis；(C) reproduction；(D) All of the choices are correct.

4. Which statement regarding the DNA and RNA is false? (A) DNA has a main function of storing our genetic code, while RNA is used in units to build specific proteins in a cell；(B) DNA is a long two-sided molecule while RNA is a shorter single-sided molecule；(C) DNA is a molecule that stores and regulates our genetics, while RNA is used for cellular energy storage and release for biological functions；(D)DNA and RNA share all nucleotides, except that RNA has Uracil instead of Thymine.

5. The original three tenets of the cell theory are__? (A) all organisms have DNA, all organisms are made of cells, and all cells produce proteins；(B) all organisms are made of one or more cells, the cell is the fundamental unit of life, and all cells come from preexisting cells；(C) all organisms are made of one or more cells, all cells contain DNA, and all cells come from preexisting cells；(D) all organisms have DNA, DNA is the fundamental unit of life, and all cells come from preexisting cells.

7. Which statement about the eukaryotic cell is correct? (A) does not have membrane-bounded organelles；(B) has a cell wall with peptidoglycan；(C) is usually smaller than a prokaryotic cell；(D) has membrane-bounded organelles.

8. Penicillin suppresses bacterial infections by__? (A) stimulating a person's immune system；(B) interfering with the construction of the cell wall；(C) by causing the DNA of a bacterium to mutate；(D) damaging the cell membrane.

9. Which one is the function of the nucleolus? (A) protein synthesis；(B) transport of material into and out of the nucleus；(C) assembly of mRNA；(D) assembly of components of ribosomes.

10. Which of the following organelles are also cellular digestion centers? (A) lysosomes and Golgi apparatus；(B) peroxisomes and ribosomes；(C) lysosomes and peroxisomes；(D) chloroplasts and ribosomes.

11. Which statement about the cytoskeleton is NOT correct? (A) a system of tracks used for intracellular transport；(B) composed of microtubules, microfilaments, and intermediate filaments；(C) a structure that aids in the process of cell division；(D) found in the cytoplasm of prokaryotic cells.

12. Oxidation means__? (A) the loss of electrons from a molecule；(B) the loss of oxygen by a cell； (C) the gain of electrons by a molecule；(D) the gain of oxygen by a cell.