Lester Bio Quiz Part 1

Which of the following organelles are enclosed by a double membrane?

A. only central vacuoles

B. nuclei and lysosomes

C. nuclei and chloroplasts

D. only nuclei

C. nuclei and chloroplasts

Plasmodesmata in plant cells are most similar in function to which of the following structures in animal cells?

A. peroxisomes

B. gap junctions

C. desmosomes

D. tight junctions

E. extracellular matrix

B. gap junctions

Plastids are only found in which of the following types of cells or organisms?

A. plant cells

B. archaea

C. bacteria

D. animal cells

A. plant cells

Ions can travel directly from the cytoplasm of one animal cell to the cytoplasm of an adjacent cell through

A. gap junctions.

B. plasmodesmata.

C. tight junctions.

D. desmosomes.

E. intermediate filaments.

A. gap junctions.

Following activation of a receptor, which sequence below represents the correct order in which components will be involved in a signaling pathway that utilizes the second messenger cAMP?

A. G protein → cAMP → adenyl cyclase → protein kinase

B. protein kinase → G protein → adenyl cyclase → cAMP

C. cAMP → adenyl cyclase → protein kinase → G protein

D. G protein → adenyl cyclase → cAMP → protein kinase

E. adenyl cyclase → cAMP → G protein → protein kinase

D. G protein → adenyl cyclase → cAMP → protein kinase

The temperature at which an alligator's egg is incubated will determine the sex of the offspring. The dependent and the independent variables in this experiment are ____

A. number of offspring and temperature in the incubator respectively

B. temperature and sex of the baby alligator respectively

C. size of the incubator and size of the baby alligator respectively

D. sex of the baby alligator and temperature respectively

D. Sex of the baby alligator and temperature respectively

Which of the following are qualities of any good scientific hypothesis?

I. It is testable.

II. It is falsifiable.

Ill. It produces quantitative data.

IV. It produces results that can be replicated.

A. I and II

B. III and IV

C. III only

D. I only

A. I and II

Which of these provides evidence of the common ancestry of all life?

A. near universality of the genetic code

B. structure of the nucleus

C. structure of chloroplasts

D. structure of cilia

A. near universality of the genetic code

The process by which the information in a gene directs the synthesis of a protein is

called

A. replication

B. post translation modification

C. gene expression

D. cloning

C. Gene expression

Why is a scientific topic best discussed by people of varying points of view, from

different subdisciplines, and representing diverse cultures?

A. Robust and critical discussion between diverse groups improves scientific

thinking

B. This is a way of ensuring that everyone gets the same results.

C. People need to exchange their ideas with other disciplines and cultures because

everyone has a right to an opinion in science.

D. Scientists can coordinate with others to conduct experiments in similar ways.

A. Robust and critical discussion between diverse groups improves scientific

thinking,

You are suffering from Streptococcus throat infection. You share the following with the bacteria that is responsible for your condition.

A. You both belong to the same domain.

B. You both have genetic material in your nucleus.

C. You both are made up of cells.

D. You and Streptococcus have nothing in common.

C. You both are made up of cells.

Which of the following types of cells utilize deoxyribonucleic acid (DNA) as their genetic material but do not have their DNA encased within a nuclear envelope?

A. fungi

B. animal

C. plant

D. archaean

D. Archaean

How does a scientific theory differ from a scientific hypothesis?

A. Hypotheses are usually an explanation for a more general phenomenon; theories

typically address more specific issues.

B. Theories are proposed to test scientific hypotheses.

C. Theories are usually an explanation for a more general phenomenon; hypotheses

typically address more specific issues.

D. Confirmed theories become scientific laws; hypotheses become theories.

C. Theories are usually an explanation for a more general phenomenon; hypotheses

typically address more specific issues.

The application of scientific knowledge for some specific purpose is known as

A. pure science

B. technology

C. inductive science

D. deductive science

B. technology

Which bond or interaction would be difficult to disrupt when compounds are put into water?

A. covalent bonds between carbon atoms

B. ionic and hydrogen bonds

C. ionic bonds

D. hydrogen bonds

A. covalent bonds between carbon atoms

Oxygen has an atomic number of 8 and, most commonly, a mass number of 16. Thus, what is the atomic mass of an oxygen atom?

A. approximately 16 grams

B. approximately 8 grams

C. approximately 16 daltons

D. approximately 8 daltons

C. approximately 16 daltons

If an atom has a charge of +1, which of the following must be true?

A. It has the same number of protons as electrons

B. It has two more protons than neutrons.

C. It has one more proton than it does electrons

D. It has one more electron than it does protons.

C. It has one more proton than it does electrons

Nitrogen (N) normally forms three covalent bonds with a valence of five. However, ammonium has four covalent bonds, each to a different hydrogen (H) atom (H has a valence of one). What do you predict to be the charge on ammonium?

A. -2

B. -1

C. +1

D. +2

C. +1

About 25 of the 92 natural elements are known to be essential to life. Which 4 of these 25 elements make up approximately 96% of living matter?

A. carbon, oxygen, phosphorus, hydrogen

B. oxygen, hydrogen, calcium, nitrogen

C. carbon, hydrogen, nitrogen, oxygen

D. carbon, sodium, hydrogen, nitrogen

C. carbon, hydrogen, nitrogen, oxygen

A covalent bond is likely to be polar when ________.

A. the two atoms sharing electrons are of the same elements

B. carbon is one of the two atoms sharing electrons

C. one of the atoms sharing electrons is more electronegative than the other atom

D. the two atoms sharing electrons are equally electronegative

C. one of the atoms sharing electrons is more electronegative than the other atom

What is the difference between covalent bonds and ionic bonds?

Question 7 options:

A. Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the sharing of protons between charged atoms.

B. Covalent bonds involve the sharing of pairs of electrons between atoms; ionic bonds involve the sharing of single electrons between atoms

C. Covalent bonds involve the transfer of electrons between charged atoms; ionic bonds involve the sharing of electrons between atoms.

D. Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the electrical attraction between charged atoms.

D. Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the electrical attraction between charged atoms.

Which of the following is broken when water evaporates?

A. nonpolar covalent bonds

B. polar covalent bonds

C. hydrogen bonds

D. ionic bonds

C. hydrogen bonds

What is the maximum number of covalent bonds that an oxygen atom with atomic number 8 can make with hydrogen?

A. 1

B. 6

C. 4

D. 2

D. 2

The atomic number of nitrogen is 7. Nitrogen-15 has a greater mass number than nitrogen-14 because the atomic nucleus of nitrogen-15 contains ________.

A. 7 neutrons

B. 15 protons

C. 8 neutrons

8. Protons

C. 8 neutrons

Lactase is an enzyme composed of a single polypeptide that hydrolyzes the disaccharide lactose to produce monosaccharides. The optimal pH for lactase activity is 6. Transfer of lactase to pH 5 results in a substantial decrease in enzyme activity, likely due to the disruption of

A. the primary and secondary structures of the enzyme.

B. only the primary structure of the enzyme.

C. the secondary and tertiary structures of the enzyme.

D. the secondary, tertiary, and quaternary structures of the enzyme.

C. the secondary and tertiary structures of the enzyme.

Which of the following functional groups confers the properties of an acid on amino acids?

A. amino

B. phosphate

C. carboxyl

D. hydroxyl

E. carbonyl

C. carboxyl

Why are hydrocarbons insoluble in water?

A. They are hydrophilic.

B. The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages.

C. They exhibit considerable molecular complexity and diversity.

D. The majority of their bonds are polar covalent carbon-to-hydrogen linkages.

B. The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages.

If 14C-labeled uracil is added to the growth medium of cells, what macromolecules will be labeled?

A. proteins

B. RNA

C. both DNA and RNA

D. DNA

E. polysaccharides

B. RNA

Testosterone and estradiol are male and female sex hormones, respectively, in many vertebrates. How do these molecules differ from each other?

A. Testosterone and estradiol are cis-trans isomers but have the same molecular formula.

B. Testosterone and estradiol have different functional groups attached to the same carbon skeleton.

C. Testosterone and estradiol are structural isomers but have the same molecular formula.

D. Testosterone and estradiol are enantiomers of the same organic molecule.

B. Testosterone and estradiol have different functional groups attached to the same carbon skeleton.

The difference between the sugar in DNA and the sugar in RNA is that the sugar in DNA

A. is in the α configuration, and the sugar in RNA is in the β configuration.

B. contains one less oxygen atom than the sugar in RNA.

C. is a five-carbon sugar, and the sugar in RNA is a six-carbon sugar.

D. is a six-carbon sugar, and the sugar in RNA is a five-carbon sugar.

B. contains one less oxygen atom than the sugar in RNA.

How many molecules of water are needed to completely hydrolyze a polysaccharide that is 10 monomers long?

A. 12

B. 10

C. 9

D. 11

C. 9

Collagen is a protein made of three identical polypeptides composed primarily of α helix structure. The α helix is an example of a

A. secondary structure stabilized by covalent bonds.

B. tertiary structure stabilized by covalent bonds.

C. tertiary structure stabilized by hydrogen bonds.

D. secondary structure stabilized by hydrogen bonds.

E. secondary structure stabilized by ionic bonds

D. secondary structure stabilized by hydrogen bonds.

Which of the following statements is true regarding cellulose?

A. It is a polymer of glucose joined by α glycosidic linkages.

B. t is a primary structural component of plant cell walls.

C. It is digestible by bacteria in the human gut.

D. It is a polymer composed of enantiomers of glucose.

E. It is a storage polysaccharide for energy in plant cells.

B. It is a primary structural component of plant cell walls.

If a DNA sample were composed of 20% guanine, what would be the percentage of cytosine?

A. 30

B. 60

C. 40

D. 20

D. 20

A researcher disrupts cells and separates subcellular components using centrifugation. Which of the following correctly lists the order in which cellular components will pellet when disrupted cell mixtures are centrifuged at increasingly higher speeds?

A. ribosomes, nuclei, mitochondria

B. nucleus, ribosomes, chloroplasts

C. chloroplasts, ribosomes, pieces of membrane

D. nucleus, mitochondria, ribosomes

D. nucleus, mitochondria, ribosomes

What is the primary reason that a modern transmission electron microscope (TEM) can resolve biological structures as small as 2 nm, whereas 200 nm is the limit of resolution for a light microscope?

A. TEM is used to visualize very thin sections of cells.

B. Contrast is enhanced by staining with atoms of heavy metal.

C. Diffraction of light by a light microscope distorts the image.

D. Electron beams have much shorter wavelengths than visible light.

D. Electron beams have much shorter wavelengths than visible light.

A mutation that inactivates an enzyme involved in the modification of sugars associated with glycoproteins is most likely to affect the function of which of the following cellular structures?

A. transport vesicles produced by the rough ER

B. smooth ER

C.transport vesicles produced by the trans face of the Golgi apparatus

D. cisternae of the Golgi apparatus

D. cisternae of the Golgi apparatus

Which of the following molecules or structures may be found in eukaryotic cells but not in bacteria?

A. endoplasmic reticulum

B. ribosomes

C. flagella

D. DNA

E. plasma membrane

A. endoplasmic reticulum

The liver is involved in the detoxification of many poisons and drugs. Which of the following structures is primarily involved in this process and therefore abundant in liver cells?

A. nuclear envelope

B. Golgi apparatus

C. rough ER

D. lysosomes

E. smooth ER

E. smooth ER

Which organelle occupies much of the volume of a plant cell?

A. nucleus

B. mitochondrion

C. Golgi apparatus

D. peroxisome

E. central vacuole

E. central vacuole

Which of the following statements concerning cells of bacteria and archaea is correct?

A. Chromosomes in both archaea and bacteria contain DNA.

B. Mitochondria are present in some bacteria and all archaea.

C. Archaea contain a membrane-bound nucleus; bacteria do not.

D. Archaea contain small membrane-enclosed organelles; bacteria do not.

A. Chromosomes in both archaea and bacteria contain DNA.

Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules?

A. lipids

B. glycogen

C. proteins

D. nucleic acids

E. cellulose

C. proteins

Proteins that will be exported from the cell are synthesized by which of the following cellular components?

A. free cytoplasmic ribosomes

B. smooth ER

C. Golgi vesicles

D. lysosomes

E. rough ER

E. rough ER

Which of the following structures plays a major role in making skin tissue water tight?

A. tight junctions

B. plasmodesmata

C. integrins

D. desmosomes

E. gap junctions

A. tight junctions

Proteins that will be exported from the cell are synthesized by which of the following cellular components?

A. free cytoplasmic ribosomes

B. smooth ER

C. Golgi vesicles

D. lysosomes

E. rough ER

E. rough ER

A researcher disrupts cells and separates subcellular components using centrifugation. Which of the following correctly lists the order in which cellular components will pellet when disrupted cell mixtures are centrifuged at increasingly higher speeds?

A. ribosomes, nuclei, mitochondria

B. nucleus, ribosomes, chloroplasts

C. chloroplasts, ribosomes, pieces of membrane

D. nucleus, mitochondria, ribosomes

D. nucleus, mitochondria, ribosomes

Which of the following molecules or structures may be found in eukaryotic cells but not in bacteria?

A. endoplasmic reticulum

B. ribosomes

C. flagella

D. DNA

E. plasma membrane

A. endoplasmic reticulum

Which of the following molecules is required to build cilia or flagella?

A. tubulin

B. keratin

C. myosin

D. actin

A. tubulin

Extracellular matrix proteins are produced by ribosomes in which part of a eukaryotic cell?

A. lysosomes

B. Golgi apparatus

C. cytoplasm

D. rough ER

E. nuclear envelope

D. rough ER

The liver is involved in detoxification of many poisons and drugs. Which of the following structures is primarily involved in this process and therefore abundant in liver cells?

A. nuclear envelope

B. Golgi apparatus

C. rough ER

D. lysosomes

E. smooth ER

E. smooth ER

A protein that spans the phospholipid bilayer one or more times is

A. a transmembrane protein.

B. a peripheral protein.

C. a glycoprotein.

D. an extracellular matrix protein.

A. a transmembrane protein.

The fluid mosaic model of membrane structure suggests that membranes

A. are composed of protein molecules embedded in a fluid bilayer of phospholipids.

B. are composed of a fluid phospholipid bilayer sandwiched between two layers of hydrophilic proteins.

C. are composed of a single fluid layer of phospholipids and proteins.

D. are composed of a fluid bilayer of fatty acids with proteins associated on the outer and inner surfaces.

A. are composed of protein molecules embedded in a fluid bilayer of phospholipids.

The electrochemical gradient across a membrane would generally be increased by which of the following membrane proteins?

A. a sodium ion channel

B. a sucrose-proton cotransporter

C. a hydrogen ion pump

D. a calcium ion channel

C. a hydrogen ion pump

Based on the fluid mosaic model of cell membranes, which of the following statements about membrane phospholipids is true?A. They frequently leave the bilayer and dissolve in the surrounding solution.

B. They frequently flip-flop from one side of the membrane to the other.

C. They occur in an uninterrupted bilayer, with membrane proteins restricted to the surface of the membrane.

D. They can move laterally along the plane of the membrane.

D. They can move laterally along the plane of the membrane.

What kinds of molecules pass through a cell membrane most easily?

A. large hydrophobic

B. small hydrophobic

C. small ionic

D. large and hydrophilic

E. large polar

B. small hydrophobic

Submerging a red blood cell in distilled water will result in

A. lysis of the cell.

B. plasmolysis of the cell.

C. the cell becoming turgid.

D. the cell becoming flacid.

A. lysis of the cell.

The primary function of G proteins in signal transduction is

A. binding extracellular signal molecules to activate the pathway.

B. converting ATP to cATP to amplify the signal.

C. transmitting the signal from an activated receptor to the next protein in the pathway.

D. phosphorylating relay molecules in the pathway.

C. transmitting the signal from an activated receptor to the next protein in the pathway.

Which of the following statements about diffusion is correct?

A. It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration.

B. It is an active process in which molecules move from a region of lower concentration to one of higher concentration.

C. It is a passive process in which molecules move from a region of lower concentration to a region of higher concentration.

D. It requires an expenditure of energy by the cell.

EIt is very rapid over long distances.

A. It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration.

The primary function of kinases in signal transduction is to

A. activate protein kinases or other relay molecules in a series.

B. inactivate second messengers such as cAMP.

C. inactivate relay molecule to turn off signal transduction.

D. regulate gene expression by serving as a transcription factor.

A. activate protein kinases or other relay molecules in a series.

Which of the following is true of natural selection?

A. It requires genetic variation, results in descent with modification, and involves differential reproductive success

B. It requires genetic variation

C. Results in descent with modification

D. Involves differential reproductive success

A. It requires genetic variation, results in descent with modification, and involves differential reproductive success