the following characteristics are possessed by ALL living things except:a) evolutionary adaptationsb) an inherited information base of DNAc) responding to the environmentd) energy processinge) photosynthesis
e) photosynthesis
organisms interact with their environments, exchanging matter and energy. For example, plant chloroplasts convert the energy of sunlight intoa) carbon dioxide and waterb) the potential energy of chemical bondsc) kinetic energyd) oxygene) the energy of motion
b) the potential energy of chemical bonds
which of the following sequences represents the hierarchy of biological organization from the least to the most complex level?a) organelle, tissue, biosphere, ecosystem, population, organismb) organism, community, biosphere, molecule, tissue, organc) cell, community, population, organ system, molecule, organelled) molecule, cell, organ system, population, ecosystem, biospheree) ecosystem, cell, population, tissue, organism, organ system
d) molecule, cell, organ system, population, ecosystem, biosphere
choose the answer that best describes the sequence of the scientific method.a) experiment, observation, hypothesis, conclusionb) observation, hypothesis, experiment, conclusionc) hypothesis, experiment, observation, conclusiond) observation, hypothesis, experiment, absolute facte) guess, hypothesis, experiment, conclusion
b) observation, hypothesis, experiment, conclusion
the liver releases glucose into the bloodstream if you dont eat for a long time. this represents an example of a characteristic possessed by all living things. which is it?a) being able to reproduceb) possessing an inherited information basec) homeostasisd) assimulation of energye) none of the above
c) homeostasis
which one or more of the following believed in abiogenesis (spontaneous generation)?a) aristotleb) jean babtiste van helmontc) francisco redid) b & c onlye) a and b only
e) a and b only
the questions that can be answered by science are:a) limited by what can be investigated using the scientific methodb) limited only by imaginationc) without limitd) limited by religious doctrinee) limited by what is found in the living world
a) limited by what can be investigated using the scientific method
when pasteur tested the hypothesis of spontaneous generation, he compared the ability of a sterilized growth medium (meat broth) to produce a population of bacteria in two different types of flasks. one had a simple neck open to the outside, and the other had a "goose neck" bend that also was open to the environment. pasteur expected that bacteria would appear in the flask with the standard neck. in this experiment, the goose neck flask served as:a) a controlb) a hypothesisc) an observationd) a statistice) a variable
e) a variable
each element is unique and different from other elements because of the number of protons in the nuclei of its atoms. which of the following indicates the number of protons in an atom's nucleus?a) atomic numberb) mass weightc) mass numberd) atomic masse) atomic weight
a) atomic number
an atom whose atomic number is 11 has how many electrons in its outermost energy level?a) oneb) tenc) elevend) twoe) eight
a) one
calcium has an atomic number of 20 and an atomic mass of 40. therefore, a calcium atom must havea) 20 protonsb) 40 neutronsc) 40 electronsd) a and b onlye) a, b, and c
a) 20 protons
the atomic number of neon is 10. therefore, which of the following is correct about an atom of neon?a) it has 8 electrons in its outer electron shellb) it is inertc) it has ten neutrons in its nucleusd) a and b onlye) a, b, and c are correct
a and b only
different atomic forms of an element contain the same number of protons but a different number of neutrons. what are these different atomic forms called?a) ionsb) isomersc) radioactive atomsd) neutronic atomse) isotopes
e) isotopes
in some vintage science fiction movies, space travelers find themselves on a planet orbiting a distant star in which there are curious forms of life based on silicon instead of carbon. Although the story clearly is sci-fi, there is an aura of plausibility in the choice of silicon, an atom with 14 protons, in place of carbon as this alien life-form's central atom. the reason is that silicon: a) has four electrons in its outermost shellb) is an isotope of carbonc) is lighter than carbond) has one or more proton than carbon so is very similar to ite) is heavier than carbon
a) has four electrons in its outermost shell
what is the difference between covalent bonds and ionic bonds?a) covalent bonds involve the transfer of electrons between atoms, and ionic bonds involve the sharing of neutrons between atomsb) covalent bonds involve the sharing of neutrons between atoms, and ionic bonds involve the sharing of electrons between atomsc) covalent bonds involve the sharing of electrons between atoms, and ionic bonds involve the electrical attraction between atomsd) covalent bonds involve the sharing of protons between atoms, and ionic bonds involve the sharing of neutrons between atomse) covalent bonds involve the sharing of protons between atoms, and ionic bonds involve the sharing of electrons between atoms
c) covalent bonds involve the sharing of electrons between atoms, and ionic bonds involve the electrical attraction between atoms
a molecule that does not have a net electrical charge at one end of the molecule as opposed to the other end isa) an isotopeb) nonpolarc) a solventd) polare) a reactant
b) nonpolar
the slight negative charge at one end of one water molecule is attracted to the slight positive charge of another water molecule. what is this attraction called?a) a covalent bondb) a hydrogen bondc) an ionic bondd) a hydrophilic bondc) a hydrophobic bond
b) a hydrogen bond
which type of bond must be broken for water to vaporize?a) polar covalent bondsb) hydrogen bondsc) covalent bondsd) ionic bondse) nonpolar covalent bonds
b) hydrogen bonds
you mix sugar in water and stir until it's completely dissolved. in this system, the water is the ____, the sugar is the ____, and the end result is a ____.a) solvent;solute;solutionb) solute;solution;solventc) solvent;solution;soluted) solute;solvent;solutione)solution;solvent;solute
a)solvent;solute;solution
in what ways are hydrogen bonds and ionic bonds similar?a) both are based on attraction between atoms that carry differences in electrical chargeb) both involve an even sharing of electrons between atomsc) both are based on attraction between two atoms where each carries a positive charged) both are based on attraction between two atoms where each carries a negative chargee) both are based on repulsion between atoms that carry differences in electrical charge
a) both are based on attraction between atoms that carry differences in electrical charge
when an acid mixes with pure watera) there is no change in pHb) the solution becomes coolerc) the number of hydroxide ions increased) the pH rises above 7e) the number of hydrogen ions increase
e) the number of hydrogen ions increase
what is it about carbon-12, carbon-13, an carbon-14 that makes them all carbon?a) they are all elementsb) they all have the number of protons that is characteristic of carbonc) they all have the number of protons plus neutrons that is characteristic of carbond) they all have the number of neutrons that is characteristic of carbone) they all are radioactive
b) they all have the number of protons that is characteristic of carbon
what is the difference between an ionic and covalent bond?a) ionic bonding involves the inner electron shells; covalent bonding involves the valence electron shellb) in an ionic bond, one tom accepts electrons from the other; in a covalent bond, a pair of atoms share electrons.c) in an ionic bond, one atom has more electronegativity than the other; in a covalent bond, the atoms have the same electronegativity. d) ionic bonds form between atoms of different elements; covalent bonds form between atoms of the same element.
b) in an ionic bond, one atom accepts electrons from the other; in a covalent bond, a pair of atoms share electrons
which of the following solutions has the greatest concentration of hydroxide ions [OH-]?a) lyeb) human bloodc) baking sodad) gastric juicee) water
a) lye
molecules of water stick to each other because:a) water molecules are nonpolar, and nonpolar molecules stick togetherb) covalent bonds form between the hydrogen atom of one molecule and the oxygen atom of another moleculec) hydrogen bonds form between the hydrogen atom of one molecule and the oxygen atom of another moleculed) hydrogen bonds form between the hydrogen atom of one molecule and a hydrogen atom of another molecule.
c) hydrogen bonds form between the hydrogen atom of one molecule and the oxygen atom of another molecule
what kind of molecules tend to be repelled by water?a) hydrophillicb) electrically charged c) hydrophobicd) acidic
a) hydrophillic
the high specific heat and surface tension of water are a result of:a) hydrogen bonding between water moleculesb) the size of water moleculesc) ionic bondsd) covalent bonds between water moleculese) covalent bonds within the water molecules
e) covalent bonds within the water molecules
which of the following statements is true regarding the carbon atoms present in all organic molecules?a) they were incorporated into organic molecules by plantsb) they were processed into sugars through photosynthesisc) they are ultimately derived from carbon dioxided) a and c onlye) a, b, and c
a) they were incorporated into organic molecules by plants
which of the above is a hydroxyl functional group?a) -OH
a) -OH
a molecule with the chemical formula C6H1206 is probably aa) lipidb) carbohydratec) monosaccharided) b and c onlye) a, b, and c
d) b and c only
a functional group added to a hydrocarbon usually makes the hydrocarbon:a) an isomerb) hydrophobicc) radioactived) nonpolare) polar
e) polar
glycogen is a polysaccharide used for energy storage by which organism?a) bacteriab) fungic) animalsd) plants
c) animals
how many different amino acids are found in protein?a) 30b) 40c) 20d) 10e) none of the above
c) 20
which of the following is the least healthy of the lipids?a) phospholipidsb) trans fatsc) saturated fatsd) omega-3 fatty acidse) polyunsaturated fats
b) trans fats
which of the following is a monosaccharide?a) chitinb) galactosec) starchd) cellulosee) glycogen
b) galactose
which of the following contains both a carboxyl group and an amino group?a) lipidsb) nucleotidesc) carbohydratesd) amino acids
d) amino acids
alpha helices and beta pleated sheets are examples of the _________ of proteinsa) primary structureb) secondary structurec) quaternary structured) tertiary structure
b) secondary structure
which of the following is an anabolic steroid?a) estrogenb) testosteronec) glycolipidsd) omega-3 fatty acids
b) testosterone
which of the following has the most calories per gram?a) proteinsb) carbohydratesc) mineralsd) cell walls of plantse) fat
e) fat
what are the monomers of a neutral fat (triglyceride)?a) sugarsb) glycerol and fatty acidsc) nucleotidesd) amino acidse) carboxyl acids
b) glycerol and fatty acids
you love to eat potato chips, but you realize they contain fats that can negatively effect your health because they can:a) cause you to have more HDL than LDLb) cause you to have more LDL than HDLc) cause you to have no LDLd) cause you to have no HDL
b) cause you to have more LDL than HDL
all of the following are proteins excepta) human growth hormoneb) plant cell wallsc) enzymesd) myosin and actine) fibrinogen
b) plant cell walls
if you could label the hydrophobic portion of the plasma membrane with a red dye, where would you find a red color:a) on the interior portion of the plasma membrane bilayer, associated with the fatty acid tailsb) on either side of the bilayer, associated with the polar head groupsc) dotted across the membrane wherever a transport protein was locatedd) on the glycocalyx, out side the membrane
a) on the interior portion of the plasma membrane bilayer, associated with the fatty acid tails
which of the following is not a function of the plasma membrane proteins?a) structural supportb) communicationc) protein synthesisd) recognitione) transport
c) protein synthesis
how does glucose gain entrance to a cell?a) an electrical signal is passed through the blood, opening glucose channels within the membrane of cellsb) glucose pokes a hole in the cell's membrane, creating a channel through which it can movec) insulin molecules bind to glucose receptors, causing cellular responses to take up glucosed) the glucose molecules diffuse through the membrane
c) insulin molecules bind to glucose receptors, causing cellular responses to take up glucose
which of the following statements about the phospholipids that make up the plasma membrane is true?a) the phosphate group is polar and therefore hydrophobic, meaning it loves to associate with waterb) the phosphate group is polar and therefore hydrophilic, meaning it loves to associate with waterc) the phosphate group is nonpolar and therefore hydrophobic, meaning it hates to associate with waterd) the phosphate group is polar and therefore hyrdrophilic, meaning it hates to associate with watere) the phosphate group is polar and therefore hydrophobic, meaning it hates to associate with water
b) the phosphate group is polar and therefore hydrophilic, meaning it loves to associate with water
free water is not water bound to solute. when a human cell is placed into water, it swells. this is said to be due to osmosis. what's happening to make the cell swell?a) water is being pulled into the cell by the cell's solutes.b) water is diffusing across the plasma membrane from a region of lower solute concentration to a region of higher solute concentrationc) solutes are being drawn into the cell across the plasma membraned) the cell synthesizes new biological macromolecules as a protective response against a watery environment e) water is diffusing across the plasma membrane from a region of low (outside the cell) to high (inside the cell) "free" water concentration
b) water is diffusing across the plasma membrane from a region of lower solute concentration to a region of higher solute concentration
it seems that bacteria and molds should grow well in jam. it's extremely high in sugar, a substance many cells can use for energy, and contains enough other nutrients to support cell growth. yet jam can be left unrefrigerated for a very long time without contamination by microorganisms. how can this be?a) the high sugar concentration causes bacterial and mold cells to swell and ruptureb) the high sugar concentration causes bacterial and mold cells to shrink and diec) bacteria and molds cannot get into the jam because its high concentration of sugar makes it so stickyd) the high sugar concentration damages cell membranese) bacteria and molds cannot grow on fruit products
b) the high sugar concentration causes bacterial and mold cells to swell and rupture
white blood cells engulf bacteria through which of the following process?a) receptor-mediated exocytosisb) phagocytosisc) osmosisd) pinocytosise) both a and b
b) phagocytosis
during osmosis, water always moves from aa) hypotonic environment to a hypertonic environmentb) low free-water solution toward a high free-water solutionc) solution with more salt to a solution with less saltd) hypertonic environment to a hypotonic environment
a) hypotonic environment to a hypertonic environment
which of the following statements concerning prokaryotic and eukaryotic cells is not correct?a) eukaryotic cells contain a membrane-bound nucleusb) prokaryotic cells lack a membrane-bound nucleusc) DNA, or deoxyribonucleic acid, is present in both prokarytoic cells and eukaryotic cellsd) DNA is present in the nucleus of eukaryotic cellse) prokaryotic cells contain small membrane-enclosed organelles
e) prokaryotic cells contain small membrane-enclosed organelles
which scientist(s) did experiments that were consistent with the concept of biogenesis?a) francisco redib) aristotlec) jean baptiste van helmontd) b and c onlye) a, b, and c
a) francisco redi
when pasteur....STANDARD necka) a statisticb) an observationc) a hypothesisd) a variablee) a control
e) a control
what is the half life of carbon 14?a) 5730 yearsb) 20,850 yearsc) 10,730 yearsd) 30,630 years
a) 5730 years
which of the following results from a transfer of electron(s) between atoms?a) hydrogen bondb) nonpolar covalent bondc) polar covalent bondd) hydrophobic interactione) ionic bond
e) ionic bond
sodium chloride (NaCl) crystals (table salt) form as a result of:a) the lack of chemical attractionb) chemical unreactivityc) the attraction of oppositely charged particles for each otherd) covalent bonding
c) the attraction of oppositely charged particles for each other
when you put sugar into your morning coffee or tea, the sugar is the _____, and the tea or coffee is the ______.a) solvent, soluteb) solute, solventc) solvent, solutiond) solution, solutee) solute, solution
b) solute, solvent
as an acid mixes in water:a) the solution will cool downb) the pH remains at 7c) the number of hydroxide ions will increased) the number of hydrogen ions will increase
d) the number of hydrogen ions will increase
a given solution contains 0.0001 (10-4) moles of hydrogen ions [H+] per liter. (pH 4). which of the following best describes this solution?a) basic: H+ acceptorb) basic: H+ donorc) acidic: H+ donord) neutrale) acidic: H+ acceptor
c) acidic: H+ donor
which of the following solutions has the greatest combination of hydrogen ions [H+]?a) baking sodab) gastric juicec) waterd) household bleache) human blood
b) gastric juice
you have two beakers. one contains a solution of HCL at pH=1.0. the other contains a solution of NaOH at pH=13. into a third beaker, you slowly and cautiously pour 20mL of the HCL and 20mL of the NaOH. after complete stirring, the pH of the mixture will bea) 9.0b) 7.0c) 12.0d) 2.0e) 5.0
b) 7.0
which of the following statements best describes the carbon atoms present in all organic molecules?a) they are ultimately derived from carbon dioxideb) they were processed into sugars through photosynthesisc) they were incorporated into organic molecules by plantsd) only A and C are correcte) A, B, and C are correct
e) A, B, and C are correct
what do polysaccharides, such as cellulose; nucleic acids, such as DNA; and proteins, such as keratin, have in common?a) they are all nonpolarb) they are all lipidsc) they are all carbohydratesd) they are all built of chemically linked monomerse) they are all amino acids
d) they are all built of chemically linked monomers
all of the following are polysaccharides (complex carbs) excepta) celluloseb) glycogenc) chitind) starche) galactose
e) galactose
which of the following are composed of only carbon, hydrogen, and oxygen?a) phospholipidsb) glucosec) amino acidsd) DNA
b) glucose
the structure depicted above shows the a) structure of celluloseb) a helix secondary structure of a polypeptidec) b pleated sheet secondary structure of a polypeptided) double helical structure of a DNA moleculee) linkage of the a glucose monomers of starch
b) a helix secondary structure of a polypeptide
which of the following is a complex carbohydrate that cannot be digested?a) high fructose corn syrupb) cellulosec) starchesd) disaccharides
b) cellulose
nucleotides are the building blocks for:a) lipidsb) DNA and RNAc) disaccharidesd) proteinse) steroids
b) DNA and RNA
scurvy is caused by a deficiency of:a) potassiumb) ironc) iodined) ascorbic acid
d) ascorbic acid
which vitamin serves as a transcription factor in protein synthesis and is produced by skin exposed to sunlight?a) Db) Ec) thiamin (B1)d) folic acid (B9)
a) D
the measure of how blood glucose levels are affected by a given amount of carbohydrate is:a) glycemic loadb) insulin indexc) sugar inputd) monosaccharide ratio
a) glycemic load
in what way are the essential amino acids different from nonessential amino acids?a) nonessential amino acids are not necessary for any proteins we makeb) essential amino acids cannot be made and must be obtained from foodc) essential amino acids are the ones exclusively used to make enzymesd) nonessential amino acids are not absorbed by the digestive tract
b) essential amino acids cannot be made and must be obtained from food
you isolate a cell with the following characteristics (1) no nucleus, (2) a cell wall, and (3) 2 um in size. this is probably aa) plant cellb) bacterial cell or a plant cellc) bacteriumd) plant cell or an animal celle) animal cell
c) bacterium
insulin is a protein made in large amounts in cells of the pancreas. these cells secrete insulin into the blood, where it controls the uptake of sugar by body cells. How is insulin transported from the ER to the surface of the cell?a) insulin is carried in small sacs of membrane (vesicles) that move from the endoplasmic reticulum to the golgi apparatus and then to the plasma membrane.b) insulin moves through plasmodesmata to the surface of the cellc) insulin is sent through the cavities (lumen) of the endoplasmic reticulum that attach directly to the plasma membraned) insulin moves along tracks of cytoskeleton proteinse) insulin is carried by lysosomes that empty their contents outside the cell
a) insulin is carried in small sacs of membrane (vesicles) that move from the endoplasmic reticulum to the golgi apparatus and then to the plasma membrane.
what is the evidence that mitochondria are descended from ancient prokaryotic cells?a) sequencing of mitochondrial DNA indicates they are degenerate eukaryotic cellsb) the organelle inside prokaryotic cells are the same as in eukaryotic cellsc) mitochondria have their own ribosomes and their own DNA both of a bacterial typed) all of the above is evidence that mitochondria and chloroplasts had a common ancestor
c) mitochondria have their own ribosomes and their own DNA both of a bacterial type
which of the following would you find in a plant cell but not an animal cell?a) mitochondrionb) lysosomec) a central vacuoled) microtubule
c) a central vacuole
which of the following statements is/are truea) anton vanleeuwenhoek discovered the existence of bacteria and protists using a crude microscopeb) robert hooke coined the term cell after viewing a slice of cork under the microscopec) aristotle believed that prokaryotic cells were due to biogenesis using carbon as the building block of matterd) A and B onlye) A, B, and C
d) A and B only
which of the following does not belong?a) oxygenb) nitrogenc) heliumd) carbone) sulfur
c) helium
you have the following known facts: smoking causes accumulation of materials in the lungs thereby decreasing the lungs ability to absorb oxygen. long term smoking causes the accumulation of material in the lungs. decreases lung capacity increases the workload of the heart. which of the following hypotheses can you make from these observations?a) long-term smokers have poorer heart health than non-smokersb) new smokers are likely to develop cancer of the lungsc) stopping smoking eliminates heart problems usually within two yearsd)stopping smoking will eliminate breathing problemse) people who never smoke never develop lung problems
a) long-term smokers have poorer heart health than non-smokers
the role of a control in an experiment is to:a) provide a basis of comparison to an experimental groupb) prove that a hypothesis is correct and ensure repeatabliityc) ensure the experiment can be repeatedd) prove a hypothesis is correct
a) provide a basis of comparison to an experimental group
which of the atoms diagrammed above is nitrogen?a)
a)
what would be the atomic number of an element with 11 neutrons, and 22 electrons?a) unable to calculate with the limited amount of information givenb) 22c) 44d) 33e) 11
b) 22
which of the following results in an ionic bond?a) the sharing of a pair of electronsb) the attraction between two polar atomsc) the loss or gain of one or more electronsd) an isotope bonding with another isotopee) both b and c
c) the loss or gain of one or more electrons
atoms form bonds to:a) obtain an equal number of protons and electronsb) obtain an equal number of protons and neutronsc) fill their outer shells with neutronsd) fill their outer shells with protonse) fill their outer shells with electrons
e) fill their outer shells with electrons
compared to 31p, the radioactive isotope 32p hasa) one more electronb) a different chargec) a different atomic numberd) one more neutrone) one more proton
d) one more neutron
butane and isobutane are isomers. this means they have the same:a) chemical formula but a different arrangement of atomsb) chemical formula but can only exist as ring structuresc) arrangement of atoms but a different chemical formulad) number of carbon atoms but different numbers of hydrogen atoms
a) chemical formula but a different arrangement of atoms
which of the following statements are true?a) the radioactive isotope carbon-14 decays into nitrogenb) the half-life of c-14 is 5730 yearsc) the "iceman" oetzi lived sometime between 5111 and 5381 years agod) A and B onlye) A, B, and C
e) A, B, and C
all of the following are true of water except:a) it is less dense as a solid than as a liquidb) neighboring molecules are held together by hydrogen bondsc) it can dissolve molecules that have an electrical charge.d) it is a polarized molecule where the oxygen is slightly positive and the hydrogens are slightly negative
d) it is a polarized molecule where the oxygen is slightly positive and the hydrogens are slightly negative
based on your knowledge of the polarity of water, the solute molecule is most likelya) neutral in chargeb) hydrophobicc) positively chargedd) negatively chargede) nonpolar
d) negatively charged
which of the following are hydrophobic?a) fatsb) sugarsc) amino acidsd) steroidse) both A and D
e) both A and D
hydroxyl groups are commonly found in:a) carbohydrates b) amino acidsc) fatty acidsd) DNA
a) carbohydrates
which of the following functional groups is acidic?a) phosphate b) aminoc) carboxyld) hydroxyl
c) carboxyl
carbohydrates such as glucose are characterized by which of the followinga) the presence of an amino acid and a carboxyl groupb) the presence of carbon and hydrogen in a ratio of 1:2c) the presence of carbon, hydrogen, and oxygen in a ratio of 1:2:1d) the presence of glycerol and fatty acids in a ratio of 2:1
c) the presence of carbon, hydrogen, and oxygen in a ratio of 1:2:1
all of the following are monosaccharides except:a) sucroseb) glucosec) fructosed) galactose
a) sucrose
chitin is a polysaccharide found in the cell walls ofa) all eukaryotesb) animalsc) plantsd) bacteriae) fungi
e) fungi
which of the following would be most likely to dissolve in olive oil?a) a hydrophilic moleculeb) a polar moleculec) vinegard) a non polar moleculee) an alcohol
d) a non polar molecule
what do fatty acids and testosterone have in common?a) they are both lipidsb) they are both steroidsc) they are both hormonesd) they are both proteins
a) they are both lipids
calories are a measure of the:a) amount of minerals and vitamins a food containsb) amount of energy the food containsc) weight of the foodd) nutritional value of food
b) amount of energy the food contains
why are the saturated fats considered a less healthy nutrient?a) saturated fats raise LDL levels, which contributes to heart diseaseb) because saturated fats are from animal sources, they can produce allergic reactionsc) saturated fats cannot be used for energy as the other fats cand) saturated fats raise HDL levels, which contributes to heart disease
a) satured fats raise LDL levels, which contributes to heart disease
in a traditional food pyramid, which type of food would be closest to the base?a) fish and poultryb) dairy productsc) whole grain foodsd) fruitse) vegetables
c) whole grain foods
all of the following statements are true except:a) saturated fats have multiple double bonds in the carbon chains of their fatty acidsb) the human liver stores some excess glucose as the polysaccharide glycogenc) oleomargerine contains more trans fats than does butterd) LDL cholesterol is one of several factors that contribute to atherosclerosise) high fructose corn syrup does not exist in nature
a) saturated fats have multiple double bonds in the carbon chains of their fatty acids
in the double-helix structure of nucleic acids, cytosine hydrogen bonds toa) guanineb) thyminec) adenined) deoxyribosee) ribose
a) guanine
all of the following are part of a prokaryotic cell except:a) ribosomesb) a cell wallc) an endoplasmic reticulumd) a cell membranee) DNA
c) an endoplasmic reticulum
who was the first person to refer to a single unit within a living organism as a "cell"?a) louis pasteurb) anton van leeuwenhoekc) robert hooked) gregor mendele) none of the above
c) robert hooke
which of the following is not one of the five principal components of a eukaryotic cell?a) cytosolb) cytoskeletonc) cell walld) nucleuse) plasma membrane
c) cell wall
which of the following is a function of the nucleolus?a) to allow mRNA to leave the nucleusb) to act as the site of DNA synthesisc) to snythesize messenger RNAd) to combine ribosomal RNA with proteins to form almost-complete ribosomese) to attach polysaccharides to protein molecules
d) to combine ribosomal RNA with proteins to form almost-complete ribosomes
which organelles are believed to have originated from free-standing bacteria ingested by ancient eukaryotic cells?a) mitochondria and chloroplastsb) mitochondria and golgi complexc) chloroplasts and lysosomesd) chloroplasts and ribosomese) lysosomes and ribosomes
a) mitochondria and chloroplasts
plasmodesmata and gap junctions are similar in that they:a) are both involved in protein synthesisb) allow cells to communicate with eachotherc) provide structural support to cellsd) form a protective lining around cells
b) allow cells to communicate with each other
which of the following is a compartment that often takes up much of the volume of a plant cell?a) golgi apparatusb) chloroplastc) lysosomed) mitochondrione) vacuole
e) vacuole
which of the following types of molecules are the major structural components of the cell membrane?a) glycoproteins and cholesterolb) phospholipids and proteinsc) nucleic acids and proteinsd) phospholipids and cellulose
b) phospholipids and proteins
what are aquaporins?a) channel proteins that allow water molecules to move very rapidly across a plasma membrane by active transportb) channel proteins that allow water molecules to move very rapidly across a plasma membrane by facilitated diffusionc) polar hydrophobic membrane proteins that act as receptors for water molecules
b) channel proteins that allow water molecules to move very rapidly across a plasma membrane by facilitated diffusion