Sample Questions for Hour Exam 1

1. A hydrogen atom has one electron. How many covalent bonds can hydrogen form?

A) one covalent bondB) two covalent bondsC) four covalent bondsD) no covalent bonds

2. Table salt is formed when

A) chlorine gives an electron to sodium.B) a hydrogen bond forms between sodium and chlorine.C) sodium and chlorine share electrons to form a bond.D) sodium donates its single outer electron to chlorine.

3. Which of the following statements regarding the oxygen atom of a water molecule is true?

A) Oxygen is more positively charged than the hydrogen atoms.B) Oxygen attracts electrons less strongly than the hydrogen atoms.C) Oxygen is more electronegative than the hydrogen atoms.D) Oxygen is attracted to the negatively charged atoms of other molecules.

4.The hydrogen atoms of a water molecule are bonded to the oxygen atom by ________ bonds, whereas neighboring water molecules are held together by ________ bonds.

A) hydrogen . . . polar covalentB) polar covalent . . . hydrogenC) ionic . . . covalentD) polar covalent . . . ionic

5. Compared to a solution of pH 3, a solution of pH 5 is

A) 100 times more acidic.B) 10 times more acidic.C) 10 times more basic.D) 100 times more basic.

6. Sucrose is formed

A) from two glucose molecules.B) from two monosaccharides through dehydration synthesis.C) when ionic bonds link two monosaccharides.D) when glucose and lactose are combined.

7. Which of the following contains a carboxyl and an amino group?

A) amino acidsB) fatsC) sugarsD) vinegar

8. Fatty acids with double bonds between some of their carbons are said to be

A) unsaturated.B) saturated.C) completely hydrogenated.D) monoglycerides.

9. How are genes used by cells to build proteins?

A) The genes in DNA direct the synthesis of an RNA molecule, which is used to build a protein.B) The genes in RNA direct the synthesis of a DNA molecule, which is used to build a protein.C) DNA is transcribed into an amino acid sequence.D) The genes in RNA direct the synthesis of proteins directly.

10. One millimeter = ________ micrometers.

A) 0.10B) 10C) 100D) 1000

11. Resolution is the

A) ability of an optical instrument to show two close objects as separate.B) size of an image.C) ability of an optical instrument to magnify an image.D) distance between the lenses of a microscope.

12. Plasma membranes are permeable to

A) large hydrophilic molecules such as starch.B) small ions such as Na+.C) nonpolar molecules such as CO2.D) hydrophilic molecules such as glucose.

13. ________ cells lack a membrane-enclosed nucleus.

A) PlantB) ProkaryoticC) EukaryoticD) Fungal

14. Unlike animal cells, plant cells have ________ and ________. Unlike plant cells, animal cells have ________.

A) chloroplasts . . . cell walls . . . centriolesB) centrioles . . . chloroplasts . . . cell wallsC) chloroplasts . . . cell walls . . . a nucleusD) centrioles . . . cell walls . . . large central vacuoles

15. Which of the following statements regarding the endomembrane system is false?

A) The endomembrane system is involved in the synthesis, storage, and export of important molecules.B) The endomembrane system includes the rough and smooth endoplasmic reticulum.C) The endomembrane system includes the nuclear envelope.D) The endomembrane system is a system of interrelated membranes that are all physically connected.

16. Secretory proteins are

A) produced by ribosomes on the smooth endoplasmic reticulum.B) chemically modified in the nucleus.C) produced by the cell for internal use.D) released from the cell through the plasma membrane.

17. Which of the following statements regarding the Golgi apparatus is false?

A) The Golgi apparatus works closely with the endoplasmic reticulum.B) The Golgi apparatus serves as a molecular warehouse and finishing factory.C) The Golgi apparatus decreases in size when a cell increases its protein production.D) The Golgi apparatus modifies chemicals received from the endoplasmic reticulum.

18. Membrane phospholipids

A) have hydrophobic heads that face the center of the membrane and are shielded from water.B) have hydrophilic tails that face outward and are exposed to water.C) are able to drift about in the plasma membraneD) remain fluid because they are tightly packed against one another.

19. Most of the functions of a cell membrane, including transport and enzymatic function, are performed by

A) glycolipids.B) proteins.C) phospholipids.D) cholesterol.

20. Which of the following statements regarding membrane function is false?

A) The plasma membrane forms a selective barrier around the cell.B) The plasma membrane plays a role in signal transduction.C) The plasma membrane has receptors for chemical messages.D) The plasma membrane is the control center of the cell.