Multiple Choice

0.4 PointsIn scanning electron microscopy, an electron beam passes through a very thin slice of a specimen and then falls onto a photographic plate or a fluorescent screen.

1. True
2. False

0.4 PointsConsider the aquatic insects pictured in the accompanying figure. Which characteristic of water molecules directly contributes to their remarkable “water walking” success?

1. adhesive forces
2. nonpolar covalent bonds
3. ionic bonds
4. capillary action
5. hydrogen bonds

0.4 PointsThe force necessary to cause microtubules of cilia and flagella to slide alongside one another is provided through the action of ____ proteins, which derive the energy to perform their work directly from ____ molecules.

1. kinesin; ADP
2. kinesin; glucose
3. dynein; ATP
4. dynein; ADP
5. tubulin; ATP

0.4 PointsProteins that are destined to become associated with the inner surface of the plasma membrane are:

1. transported to the plasma membrane within a secretory vesicle.
2. made on free ribosomes in the cytoplasm.
3. made on ribosomes located on the rough endoplasmic reticulum.
4. manufactured in the same way as protein hormones.
5. manufactured in the same way as proteins destined to become external peripheral proteins.

0.4 PointsA transmembrane protein differs from other membrane proteins because it:

1. is covalently linked to the outer surface of the plasma membrane.
2. is completely embedded within the membrane.
3. is a glycoprotein with carbohydrates attached.
4. is attached to the inside of the membrane by an ionic bond.
5. completely extends through the membrane.

0.4 PointsA hypothesis can best be described as a(n):

1. data point
2. tentative explanation
3. observation
4. stepwise problem-solving approach
5. conclusion

0.4 PointsThe primary purpose of homeostasis is to:

1. convert an organism to live in a harmful environment
2. maintain a constant internal environment
3. accept responses to stimuli
4. provide unlimited growth within an organism
5. allow unrestricted movement of an organism

0.4 PointsIn a water molecule, because oxygen is more electronegative than hydrogen, the shared electrons are more commonly found around the ____ nucleus than the ____ nucleus.

1. oxygen; hydrogen
2. oxygen; nitrogen
3. nitrogen; oxygen
4. hydrogen; other hydrogen
5. hydrogen; oxygen

0.4 PointsThe smooth ER is the primary site for the synthesis of phospholipids and cholesterol needed to make ____.

1. ribosomes
2. hormones
3. DNA
4. ATP
5. cell membranes

0.4 PointsDuring phagocytosis, what may fuse with the vacuole to further degrade the ingested material?

1. receptor
2. phosphate
3. lysosome
4. ligand
5. desmosome

0.4 PointsSuppose a particular protein is produced in excess of the cell’s needs. What kind of mechanism will intervene to stop production?

1. anabolic
2. metabolic
3. homeostatic
4. growth
5. respiratory

0.4 PointsEnzymes called proteases in the ER lumen catalyze folding of proteins into proper conformations.__________________

1. True
2. False

0.4 PointsThe largest and most complex assembly of proteins in most eukaryotic cells are the:

1. ribosomes
2. flagella
3. chromosomes
4. nuclear pores
5. smooth ER

0.4 PointsOsmotic pressure of a solution is the amount of pressure exerted on the side of the selectively permeable containing a higher concentration of solute to prevent diffusion of solute.__________________

1. True
2. False

0.4 PointsFigure 5-2

Consider the cellular process illustrated in the accompanying figure. What substance would most likely be used to transport?

1. hormones
2. bacteria
3. potassium ions
4. glucose
5. carbon dioxide

0.4 PointsIsotopes differ from each other with respect to the number of:

1. both protons and electrons.
2. protons only.
3. both neutrons and protons.
4. electrons only.
5. neutrons only.

0.4 PointsSimilar families of organisms are next grouped together in the same:

1. phylum
2. order
3. class
4. genus
5. kingdom

0.4 PointsIon channels are found in the plasma membranes of neurons and muscle cells.__________________

1. True
2. False

0.4 PointsHow is paracrine signaling different from other types of signaling?

1. The signaling molecules are transferred by electrical signals.
2. The signaling molecules are displayed on the cell surface.
3. The signaling molecules release neurotransmitters.
4. The signaling molecule are hormones.
5. The signaling molecule diffused through interstitial fluid, acting on nearby cells.

0.4 PointsIn a lipid bilayer, __________ fatty acid tails face each other within the bilayer and form a region that excludes water.

1. hypertonic
2. hyperosmotic
3. hydrophobic
4. hypotonic
5. hydrophilic

0.4 PointsHow does the scanning electron microscope differ from the transmission electron microscope?

1. The SEM gives a three dimensional image of the object being studied.
2. The SEM utilizes a beam of light that passes through the specimen.
3. The SEM can view the internal structure of a cell.
4. The SEM relies on the detection of electrons from the beam after contact with the specimens.
5. The SEM can view a live specimen.

0.4 PointsIf you observe a cell that contains organelles, then that cell is most likely a(n) prokaryote. __________________

1. True
2. False

0.4 PointsSimilar orders are placed in the same class.__________________

1. True
2. False

0.4 PointsAdenylyl cyclase catalyzes the reaction in which:

1. GTP is converted to GDP.
2. PIP2 is split.
3. a protein is phosphorylated.
4. calcium ions bind calmodulin.
5. ATP is converted to cAMP.

0.4 PointsMatch the term with its description.PromptsSubmitted Answers

1. Question 9Sticking together of like moleculesChoose a match
2. Question 9Directly responsible for the ability of certain insects to walk on waterChoose a match
3. Question 9Tendency of water to move in narrow tubesChoose a match
4. Question 9Sticking together of unlike moleculesChoose a match

0.4 PointsAn organism that reproduces asexually produces genetically variable offspring.__________________

1. True
2. False

0.4 PointsPeripheral proteins are linked to either surface of the plasma membrane by:

1. associating with glycoproteins on the inner membrane surface.
2. covalent disulfide bonds.
3. bonding to integral proteins through noncovalent interactions.
4. associating with fatty acids through hydrophobic interactions.
5. embedding in one side of the membrane and, thus, not extending through to the other side.

0.4 PointsIf the concentration of solutes in a cell is less than the concentration of solutes in the surrounding fluid, then the extracellular fluid is said to be:

1. amphipathic.
2. hypertonic.
3. stable.
4. hypotonic.
5. isotonic.

0.4 PointsIn the sodium-potassium pump, sodium ion release causes two K+ ions to be released into the cell.__________________

1. True
2. False

0.4 PointsIntermediate filaments are most closely associated with which of the following?

1. myosin
2. keratins
3. pseudopodia
4. microvilli
5. actin

0.4 PointsIf a toxin, such as a bacterial toxin, destroys ribosomes, what cellular activity will be affected first?

1. movement
2. DNA synthesis
3. protein synthesis
4. energy storage
5. active transport

0.4 PointsHow do the phospholipids in vegetable oil differ from those of animal fat?

1. The fatty acid tails solidify at room temperature.
2. The fatty acid tails are a chain of saturated fats.
3. The fatty acid tails interact via van der Waals forces.
4. The fatty acid tails lack double bonds.
5. The fatty acid tails bend.

0.4 PointsA chlorine atom has 17 protons and 18 neutrons. What is its atomic mass?

1. 1 amu
2. 306 amu
3. 18 amu
4. 17 amu
5. 35 amu

0.4 PointsLDL cholesterol is taken into the cell by receptor-mediated endocytosis.__________________

1. True
2. False

0.4 PointsAn example of a(n) anion is K+.__________________

1. True
2. False

0.4 PointsOxidation occurs when an atom gains one or more electrons.__________________

1. True
2. False

0.4 PointsThe smooth ER is the primary site for the synthesis of proteins and cholesterol needed to make membranes.__________________

1. True
2. False

0.4 PointsSince sodium-potassium pumps transport sodium ions out of a cell and potassium ions into a cell, what type of carrier proteins are they?

1. uniporters
2. symporters
3. antiporters
4. ABC transporter
5. ion pumps

0.4 PointsProteins made on ribosomes may be further modified within which organelle?

1. Golgi complex.
2. peroxisomes.
3. mitochondria.
4. lysosomes.
5. nucleus.

0.4 PointsThe outer membrane of the nuclear envelope is continuous with the membrane of the ____ and is usually covered with attached ribosomes.

1. chromatin
2. nucleolus
3. endoplasmic reticulum
4. plasma membrane
5. cell wall

0.4 PointsSodium-potassium pumps maintain a(n) electrochemical gradient.__________________

1. True
2. False

0.4 PointsThe valence shell of hydrogen or helium is unstable when it contains two electrons.

1. True
2. False

0.4 PointsA glycoprotein destined for secretion from the cell would move through the Golgi complex which sequence?

1. trans face to medial region to cis face
2. trans face to cis face to medial region
3. medial face to trans face to cis face
4. cis face to trans face to medial region
5. cis face to medial region to trans face

0.4 PointsHow do gap junctions differ from desmosomes?

1. A gap junction requires the use of ATP to open and close its channels.
2. A gap junction provides communication between cells.
3. A gap junction can control the passage of materials between cells.
4. A gap junction bridges the space between cells.
5. A gap junction is a much larger space between cells.

0.4 PointsMatch the type of bond or interaction with its description.PromptsSubmitted Answers

1. Question 8Strong attractive force resulting from the transfer of electrons between atomsChoose a match
2. Question 8Strong attractive force resulting from the sharing of electrons between atomsChoose a match
3. Question 8Very weak attractive force joining nonpolar moleculesChoose a match
4. Question 8Holds adjacent water molecules togetherChoose a match

0.4 PointsOne of the conclusions drawn from Darwin’s theory of evolution is that:

1. genetic information can pass from organism to organism by means of DNA
2. existing organisms can adapt to environmental changes
3. living organisms contain substances produced by cells
4. organisms living today descended with modifications from previously existing forms
5. living organisms are composed of basic units called cells

0.4 PointsDuring an infection, white blood cells travel to the infected site and phagocytize the pathogens. After phagocytosis, primary lysosomes fuse with the phagocytic vesicle to form a larger vesicle called a secondary lysosome. The purpose for this process is to:

1. wrap the pathogen in additional membrane, rendering them harmless.
2. introduce antibodies to the phagocytic vesicles.
3. mix the pathogens with strong hydrolytic enzymes and destroy them.
4. coat the bacteria in lipids derived from the Golgi complex, which cover and smother them.
5. degrade the bacteria and export it from the cell.

0.4 PointsThe covalent bond between a hydrogen atom and the oxygen atom in water is formed when:

1. hydrogen gains an electron from oxygen.
2. hydrogen gains an electron from oxygen.
3. hydrogen and oxygen both lose electrons from their outer shells.
4. hydrogen and oxygen share an electron pair.
5. hydrogen and oxygen both gain electrons in their outer shells.

0.4 PointsAn atom having a filled valence shell is stable and unreactive.__________________

1. True
2. False

0.4 PointsInformation in living organisms is transmitted by which mechanism(s)?

1. genes, hormones, and neurotransmitters
2. genes and hormones
3. genes only
4. neurotransmitters only
5. hormones only