campbell BIOLOGY chapter 1 ,2 ,5
An element has 8 protons, 9 neutrons, and 8 electrons. Its atomic number and atomic mass, respectively, are _____. (eText Concept 2.2) 1. 16 and 8 2. 8 and 17 3. 8 and 16 4. 9 and 16 5. 9 and 17
8 and 17 No. Atomic number relates to the number of protons, not the number of neutrons.
A particular carbon isotope has an atomic number of 6 and an atomic mass of 14. The respective number of neutrons, protons, and electrons that this carbon isotope has is _____. (eText Concept 2.2) 1. 6, 6, and 8 2. 6, 8, and 6 3. 8, 6, and 8 4. 8, 6, and 6 5. 8, 6, and 4
8, 6, and 6
There are _____ naturally occurring elements. (eText Concept 2.1) 1. 4 2. 25 3. 92 4. 108 5. 238
92 No. But 4 elements (carbon, hydrogen, oxygen, and nitrogen) do make up 96% of living matter.
A theory is _____.
A well-supported concept that has broad explanatory power.
What do Alzheimer's, Parkinson's, and mad cow disease have in common?(eText Concept 5.4) * They all cause the misfolding of nucleic acids. * All are associated with the buildup of lipids in brain cells due to faulty lysosome activity. * All have been associated with the buildup of misfolded proteins in cells. * They all associated with plaque buildup in arteries (atherosclerosis). * All are caused by the buildup of misfolded proteins in cells.
All have been associated with the buildup of misfolded proteins in cells.
Which of the following is NOT an attribute of living things?
All living things require oxygen
Enzyme molecules require a specific shape to perform their catalytic function. Which of the following might alter the shape of an enzymatic protein? (eText Concept 5.4) * mixing in a chemical that removes hydrogen bonds * a change in salt concentrations or pH * heating the protein * denaturing the protein * All of the listed responses are correct.
All of the listed responses are correct. Correct. All of the listed responses would affect the shape and therefore the catalytic activity of the enzymatic protein.
Which of the following four statements, if any, is true regarding essential elements and living organisms? 1.Given their low concentrations in nature, the toxicity of some elements is generally not a factor in the evolution of biological communities. 2.The elements carbon, hydrogen, nitrogen, and oxygen make up 20-25% of living mass. 3.All organisms require 25 of the 92 naturally occurring elements to survive. 4.Although all forms of life require iron, other elements are required only by certain species. 5.All of the listed responses are correct.
Although all forms of life require iron, other elements are required only by certain species. (Certain species of plants have evolved adaptations to survive in soils concentrated with toxic elements, such as seen among the serpentine plant communities.)
Which of the following is true regarding complementary base pairing in DNA and RNA molecules? (eText Concept 5.5) * Complementary base pairing within single strands of DNA and RNA gives them particular three-dimensional structures that are necessary for their function. * Complementary base pairing promotes an antiparallel orientation in the structure of DNA and RNA molecules. * Although the base pairing between two strands of DNA in a DNA molecule can be thousands to millions of base pairs long, base pairing in an RNA molecule is limited to short stretches of nucleotides in the same molecule or between two RNA molecules. * Although a DNA molecule demonstrates complementary base pairing between two DNA polynucleotides to form a double helix, an RNA molecule can only base pair along stretches of nucleotides in the same RNA molecule, such as in transfer RNA molecules. * None of the listed responses is correct
Although the base pairing between two strands of DNA in a DNA molecule can be thousands to millions of base pairs long, base pairing in an RNA molecule is limited to short stretches of nucleotides in the same molecule or between two RNA molecules.
Which of the following domains is prokaryotic?
Archaea
Emergent properties of living systems are defined as properties that
Are due to the arrangement and interactions of parts as complexity increases
Which of the following molecules is a monosaccharide? (eText Concept 5.2) * C25H43O8 * C22H49O10N5 * C51H98O6 * C45H84O8PN * C6H12O6
C6H12O6 Correct. Monosaccharides have molecular formulas that are multiples of CH2O.
Which of the following is the fundamental unit of structure and function in living organisms?
Cell
High cholesterol levels are considered a major risk factor for heart disease. If it is so bad for humans, why does the body make cholesterol in the first place? (eText Concept 5.3) * Cholesterol aids in the formation of amino acids that are used to build proteins. * Cholesterol is an important energy storage molecule. * Cholesterol is an important constituent of nucleotides. * Cholesterol is not important for humans any more. It is a holdover from hunter-gatherer days when food was scarce. * Cholesterol is the basis for many important molecules such as sex hormones.
Cholesterol is the basis for many important molecules such as sex hormones. Correct. Cholesterol is the basis for many steroid molecules, including sex hormones.
Two garden plots were planted with corn. The soil was similar in each, and equal amounts of water were applied to each plot. One plot was fertilized, and the other was not. The experimenters measured the yield as bushels of corn from each plot. The plot that did not receive the fertilizer was the _____. ()
Control plot
A shortage of phosphorus in the soil would make it especially difficult for a plant to manufacture _____. (eText Concept 5.5) * proteins * DNA * sucrose * cellulose * fatty acids
DNA
What is the molecule that can account for both the unity and diversity of life?
DNA
Which of the following observations and inferences led Charles Darwin to his theory of natural selection as a mechanism for evolution?
Darwin synthesized his theory of natural selection from all of the above observations and inferences.
When a protein is denatured, why does it lose its functionality? (eText Concept 5.4) * Denaturation destroys the primary structure of the protein, and the protein breaks down to monomers. * Different amino acids are substituted into the sequence, so the protein's properties change. * Denaturation breaks the weak bonds, such as hydrogen bonds and van der Waals interactions, that hold the protein in its three-dimensional shape. Without the proper shape, the protein cannot function. * Denaturation breaks the covalent bonds that hold the protein in its three-dimensional shape. Without the proper shape, the protein cannot function. * The protein's pH changes, causing it to lose its functionality.
Denaturation breaks the weak bonds, such as hydrogen bonds and van der Waals interactions, that hold the protein in its three-dimensional shape. Without the proper shape, the protein cannot function.
With evolution as the core theme of biology, we can explain traits shared by organisms as evidence of _____ and traits that differ among organisms as evidence of ___.
Descent from a common ancestor Adaptation through natural selection
Evaluate the following statement: Concentrations of trace elements in an environment above what is required by organisms generally has no effect on those organisms. (eText Concept 2.1) 1.True. Most organisms have evolved adaptations that allow them to tolerate very high concentrations of trace elements in the environment. 2.False. Elevated concentrations of trace elements such as chromium and phosphorus can be toxic. 3.False. Increasing the concentration of trace elements above what is required generally has a beneficial effect on organisms. 4.False. Elevated concentrations of some trace elements such as cobalt and chromium can be toxic. 5.True. Only trace element limitation can lead to disease among organisms.
Elevated concentrations of some trace elements such as cobalt and chromium can be toxic. ( Elevated concentrations of some trace elements are harmful to many forms of life).
Evaluate the following statement: Oxygen is not a greenhouse gas; therefore, gases containing oxygen, such as ozone, nitrous oxide, and carbon dioxide, are not greenhouse gases either. (eText Concept 2.1) 1.True. It is impossible for a gas containing oxygen to be a greenhouse gas. 2. False. Compounds can have emergent properties that are very different from the elements that form them. 3. True. Because oxygen is not a greenhouse gas, it is unlikely to combine with anything at a higher level of organization to form a greenhouse gas. 4.False. Oxygen is a special case because of its reactivity and electronegativity. 5. True. Compounds display emergent properties that are very similar to the elements that form them.
False. Compounds can have emergent properties that are very different from the elements that form them. Correct. Emergent properties of compounds are more than simply the sum of their parts.
Eukaryotic organism that decompose dead organisms and absorb the nutrients are generally found in which kingdom?
Fungi
Which of the following statements is most clearly inductively derived? ()
If the animals observed required organic molecules as nutrients, then it can be concluded that all animals require organic molecules as nutrients.
Generally, animals cannot digest (hydrolyze) the glycosidic linkages between the glucose molecules in cellulose. How then do cows get enough nutrients from eating grass? (eText Concept 5.2) * Cows and other herbivores are exceptions and make some cellulose-digesting enzymes. * They have to eat a lot of it. * Microorganisms in their digestive tracts hydrolyze the cellulose to individual glucose units. * The flat teeth and strong stomach of herbivores break the cellulose fibers so that the cows get enough nutrition from the cell contents. * All of the listed responses are correct.
Microorganisms in their digestive tracts hydrolyze the cellulose to individual glucose units. Correct. Cows have digestive chambers populated by microorganisms that can produce certain hydrolytic enzymes that cows cannot. The enzymes hydrolyze (digest) the cellulose polymer into glucose monomers.
What is a distinguishing feature of most naturally occurring fats? (eText Concept 5.3) * Nearly all naturally occurring unsaturated fats have cis double bonds. * Most unsaturated fats have trans double bonds, causing a kink in the hydrocarbon chain wherever they occur. * All organisms share an equal ratio of saturated and unsaturated fatty acids. * They all share four fused rings as a carbon skeleton. * They are distinguished from other lipid forms by their chief role as components of cell membranes. End of Question 20
Nearly all naturally occurring unsaturated fats have cis double bonds. No. Unsaturated fats with trans double bonds are formed in the industrial process of hydrogenating unsaturated plant oils.
What is a key feature of omega-3 fatty acids that distinguishes them from other types of fatty acids? (eText Concept 5.3) * It is one of the only unsaturated fatty acids that is produced by humans. * Omega-3 fatty acids are distinguished by the presence of three trans double bonds in their hydrocarbon chain. * Omega-3 fatty acids are typically lacking in a vegetarian diet and must be provided by taking animal-derived supplements. * Like other saturated fatty acids, a diet rich in omega-3 fatty acids can promote plaque formation in the blood vessels. * None of the listed responses correctly describes a distinguishing key feature of omega-3 fatty acids
None of the listed responses correctly describes a distinguishing key feature of omega-3 fatty acids.
To what does the term "polypeptide" refer? (eText Concept 5.4) * organic molecules linked by dehydration reactions * carbohydrates with a hydrogen bond holding them together * amino acids linked by hydrolysis * organic monomers covalently bonded * None of the listed responses is correct.
None of the listed responses is correct
Which of the following is a true statement comparing phospholipids and triacylglycerols (fats and oils)? (eText Concept 5.3) * Both molecules contain a phosphate group. * Phospholipids are the primary storage form for fats in our bodies. * Triacylglycerols may be saturated or unsaturated, but all phospholipids are saturated. * Phospholipid molecules have a distinctly polar "head" and a distinctly nonpolar "tail," whereas triacylglycerols are predominantly nonpolar. * In nature, phospholipids occur in fused rings (sterol form), whereas triacylglycerols maintain a straight-chain form.
Phospholipid molecules have a distinctly polar "head" and a distinctly nonpolar "tail," whereas triacylglycerols are predominantly nonpolar. Correct. Triacylglycerols consist of three (nonpolar) fatty acid tails attached to a glycerol molecule. Phospholipids have two fatty acid tails and a hydrophilic head containing a negatively charged phosphate group.
Natural selection tends to act at which of the following levels?
Population
What is the appropriate term for an interacting group of individuals of a single type occupying a define area?
Population
Which kingdom within the domain Eukarya is composed of organisms that are generally unicellular?
Protista
Sequencing a protein to discover the sequence of amino acids that make it up is an example of _________. Understanding how that protein works with other proteins in a cell is an example of __________.
Reductionism Systems Biology
Nutritionally, saturated triacylglycerols are considered to be less healthful than unsaturated triacylglycerols. What is the difference between them? (eText Concept 5.3) * Saturated triacylglycerols have more double bonds than unsaturated triacylglycerols. * Saturated triacylglycerols have more hydrogen atoms than unsaturated triacylglycerols. * Saturated triacylglycerols are fats; unsaturated triacylglycerols are carbohydrates. * Saturated triacylglycerols are liquid at room temperature. * All of the listed responses are correct.
Saturated triacylglycerols have more hydrogen atoms than unsaturated triacylglycerols. Correct. Saturated triacylglycerols are saturated with hydrogen atoms
A company was testing a new drug it thought would help decrease the risk of transmission of viruses from mother to fetus. In an experiment to test the compound, an investigator gave 400 pregnant female rats a small dose of the experimental drug and inoculated each with a type of virus known to cause disease in rats. At the same time, 400 other pregnant rats were given only the virus. Of the rat pups born to the females that received both the virus and the drug, 203 showed no symptoms of the disease; 205 rat pups born to the virus-only females showed symptoms. From these data, we can best conclude _____. ()
That the drug seems to have little effect on the viral transmission at the dosage given.
Consider a hypothetical atom with an atomic number of 4 and a net electronic charge of +1. How many neutrons does this atom have? (eText Concept 2.2) 1. one 2. three 3. four 4. The answer cannot be determined from the information provided. 5. None of the listed responses is correct.
The answer cannot be determined from the information provided. No. One of the choices is correc
Which of the following describes a difference between DNA and RNA? (eText Concept 5.5) * RNA molecules consist of a single polynucleotide chain, whereas DNA molecules consist of two polynucleotide chains organized into a double helix. * One of their nitrogenous bases is different. * They contain different sugars. * The first and second listed responses are correct differences. * The first three listed responses all describe differences.
The first three listed responses all describe differences.
How is the information encoded in DNA actually used by organisms?
The information in DNA is transcribed to RNA and then translated into protein.
Amylase is an enzyme that breaks down starch. Why can't the same enzyme break down cellulose? (eText Concept 5.2) * The enzyme cannot attack cellulose because of its helical shape. * The monosaccharide monomers in cellulose are bonded together differently than in starch. * Cellulose molecules are much too large. * The bonds between the monosaccharide monomers in cellulose are much stronger. * Starch is made of glucose; cellulose is made of fructose.
The monosaccharide monomers in cellulose are bonded together differently than in starch. Correct. The glucose monomers in cellulose are bonded in a beta glycosidic linkage, whereas those in starch have an alpha glycosidic linkage. The enzyme amylase is specific for the alpha glycosidic linkage.
Which of the following is an attribute of living things?
They must be able to evolve and adapt
Radon is a radioactive gas that seeps into homes from the soil. It is thought to be a cause of lung cancer. A research team investigates this theory. They gather large amounts of data on basement radon concentrations and lung cancer rates and conclude that the more radon there is in a home, the more likely are people living in those homes to develop lung cancer. After the study is published, other researchers criticize it by asserting that the studied neighborhoods with higher radon concentrations also have a higher percentage of older people and a higher percentage of cigarette smokers than the low-radon neighborhoods. Both advanced age and cigarette smoking increase the risk of lung cancer. This criticism, if correct, shows that the radon study suffered from _____. ()
Uncontrolled variables
Should an experiment test only one variable at a time? Why or why not? ()
Yes, an experiment should only test one variable at a time. This ensures that the experimental outcome is clearly due to one identifiable factor.
If a small droplet of triacylglycerol molecules is suspended in water, the fat molecules form a "ball of spaghetti" with no particular orientation. But if a droplet of phospholipid molecules is put in water, all the molecules point outward, toward the water. Phospholipids are forced into this orientation because phospholipids have _____. (eText Concept 5.3) * two charged ends * three fatty acid molecules, all pointing in different directions * a charged end and a noncharged end * both a saturated fatty acid and an unsaturated fatty acid * two fatty acid molecules pointing in different directions
a charged end and a noncharged end Correct. The hydrocarbon tails of phospholipids are hydrophobic and are excluded from water. The negatively charged phosphate group and its attachments form a hydrophilic head that is attracted to water.
The peptide bond is _____. (eText Concept 5.4) * a covalent bond joining amino acids together to form a polypeptide * a hydrogen bond joining amino acids together to form a polypeptide * a covalent bond joining simple sugars together to form a polypeptide * a covalent bond joining nucleotides together to form a nucleic acid * a hydrogen bond joining nucleotides together to form a nucleic acid
a covalent bond joining amino acids together to form a polypeptide
A glucose molecule is to starch as _____. (eText Concept 5.5) * a nucleic acid is to a polypeptide * a protein is to an amino acid * a nucleotide is to a nucleic acid * a steroid is to a lipid * an amino acid is to a nucleic acid
a nucleotide is to a nucleic acid
Manufacturers make vegetable oils solid or semisolid at room temperature by _____. (eText Concept 5.3) * adding hydrogen atoms to the single bonds of the fatty acid hydrocarbon chains * adding hydrogen atoms to the double bonds in the fatty acid hydrocarbon chains * removing hydrogen atoms and forming additional double bonds in the fatty acid hydrocarbon chains * removing hydrogen atoms and forming additional single bonds in the fatty acid hydrocarbon chains * None of the listed responses is correct.
adding hydrogen atoms to the double bonds in the fatty acid hydrocarbon chains No. If hydrogen atoms were removed, additional double bonds would be formed.
Which of the following is outside the realm of scientific inquiry
addressing ethical dilemmas
On the basis of the principle of complementary base pairing, you would expect the percentage of _____ to be equal to the percentage of _____. (eText Concept 5.5) * adenine ... thymine * thymine ... guanine * thymine ... cytosine * adenine ... guanine
adenine ... thymine
Experimentation is only one part of the process of scientific inquiry, but it is very important step because it _____
allows rejection of a hypotheses
Protein molecules are polymers (chains) of _____. (eText Concept 5.4) * sucrose molecules * DNA molecules * amino acid molecules * purines and pyrimidines * fatty acid molecules
amino acid molecules Correct. Polymers of amino acids are called polypeptides. A protein consists of one or more polypeptides folded into specific conformations.
The most common form of calcium has 20 protons, 20 neutrons, and 20 electrons. Which of the following elements would be an isotope of calcium? (eText Concept 2.2) 1. an atom with 21 protons, 21 neutrons, and 21 electrons 2. an atom with 20 protons, 21 neutrons, and 20 electrons 3. an atom with 20 protons, 20 neutrons, and 18 electrons 4. an atom with 21 protons, 20 neutrons, and 21 electrons 5. All of the listed responses are correct.
an atom with 20 protons, 21 neutrons, and 20 electrons No. The number of protons must stay the same for the element to remain calcium.
Lipids differ from other large biological molecules in that they _____. (eText Concept 5.3) * do not contain nitrogen and phosphorus atoms * do not have specific shapes * are much larger * are not truly polymers * do not contain carbo
are not truly polymers
Isotopes of an element will always differ in _____. (eText Concept 2.2) 1. number of protons 2. atomic mass 3. atomic number 4. number of electrons 5. None of the listed responses is correct.
atomic mass
Which of the following components of a tossed salad will pass through the human digestive tract and be digested the least? (eText Concept 5.2) * cellulose (in the lettuce) * starch (in the croutons) * protein (in the bacon bits) * sugar (in the dressing) * oil (in the dressing)
cellulose (in the lettuce) Correct. Cellulose contains glycosidic linkages that cannot be broken by human digestive enzymes.
Which of the following is a polymer? (eText Concept 5.2) cellulose, a plant cell wall component fructose, a component of sucrose glucose, an energy-rich molecule triacylglycerol, or fat testosterone, a steroid hormone
cellulose, a plant cell wall component Correct. The polysaccharide cellulose is a major component of plant cell walls. It is a polymer composed of many glucose monomers joined together by glycosidic linkages.
Which type of protein shields a newly forming protein from cytoplasmic influences while it is folding into its functional form? (eText Concept 5.4) * fibrous proteins * enzymes * receptor proteins * antibodies * chaperonins
chaperonins Correct. Chaperonins shield proteins from "bad influences" (interactions with other molecules in the cytoplasm) while they are folding into their functional forms.
At a conference, the speaker's grand finale was sautéing mealworms (insect larvae) in butter and serving them to the audience. They were crunchy (like popcorn hulls) because their exoskeletons contain the polysaccharide _____. (eText Concept 5.2) * chitin * glycogen * cellulose * collagen * linoleic acid
chitin Correct. Chitin is the structural polysaccharide found in arthropod exoskeletons.
Which of the following is a trace element? (eText Concept 2.1) 1. oxygen 2. carbon 3. hydrogen 4. nitrogen 5. copper
copper Correct. Copper (Cu) is a trace element. Copper accounts for less than 0.01% of living matter
The type of bond that forms to join monomers (such as sugars and amino acids) into polymers (such as starch and proteins) is a(n) _____ bond. (eText Concept 5.1) * hydrogen * ionic * van der Waals * peptide * covalent
covalent
In an ecosystem, nutrients _______ and energy ______.
cycle flows through
What is the process by which monomers are linked together to form polymers? (eText Concept 5.1) * coiling * protein formation * hydrolysis * monomerization * dehydration or condensation reactions
dehydration or condensation reactions
Which of the following has negligible mass? (eText Concept 2.2) 1. neutron 2. electron 3. atom 4. proton 5. element
electron No. Think subatomic. Atoms of an element are composed of subatomic particles: protons, neutrons, and electrons.
Carbohydrates are used in our bodies mainly for _____. (eText Concept 5.2) * building genetic material * lipid storage * structural molecules, such as hair and fingernails * energy storage and release * membrane construction
energy storage and release Correct. Simple sugar molecules, stored in polysaccharides such as glycogen in animals and starch in plants, are a major energy source for cellular work
The number of protons in an uncharged atom _____. (eText Concept 2.2) 1. varies with the different isotopes 2. equals the number of electrons 3. equals the number of neutrons 4. equals the number of electrons in the outer orbital of the atom 5. determines its mass number
equals the number of electrons No. The number of neutrons can differ from the number of protons in a charged or uncharged atom. For example, the different isotopes of an element would have different numbers of neutrons, but each of the different isotopes would have the same number of protons and electrons.
Some lipids are formed when fatty acids are linked to glycerol. These subunits are linked together by _____. (eText Concept 5.3) * ester linkages * glycosidic linkages * peptide bonds * ionic bonds * phosphodiester linkages
ester linkages
Which of the following carbohydrate molecules has the lowest molecular weight? (eText Concept 5.2) * glucose * cellulose * sucrose * chitin * lactose
glucose
A polysaccharide that is used for storing energy in human muscle and liver cells is _____. (eText Concept 5.2) * chitin * glucose * starch * glycogen * cellulose
glycogen
the subunits (monomers) in cellulose are linked together by _____. (eText Concept 5.2) * glycosidic linkages * peptide bonds * ionic bonds * phosphodiester linkages * ester linkages
glycosidic linkages
The best method for determining whether bean plants require sodium is to _____.
grow bean plants with and without sodium
Potassium (atomic number 19, mass number 40) and sodium (atomic number 11, mass number 23) have similar chemical properties and reactive behavior. This is because uncharged atoms of potassium and sodium _____. (eText Concept 2.2) 1. have different atomic numbers and different numbers of electrons in their outermost electron shells 2. have different atomic numbers but the same number of electrons 3. have different mass numbers and each has one electron in its outermost electron shell 4. have the same atomic number and each has one electron in its outermost electron shell 5. have different atomic numbers, different mass numbers, and different numbers of electrons in their outermost electron shells
have different mass numbers and each has one electron in its outermost electron shell No. The atoms of different elements have atomic numbers that are unique to the different elements.
What are the four most abundant elements found in living systems? (eText Concept 2.1) 1. hydrogen, oxygen, nitrogen, and carbon 2. hydrogen, oxygen, nitrogen, and carbon dioxide 3. magnesium, calcium, iron, and zinc 4. nitrogen, carbon, sulfur, and oxygen 5. hydrogen, oxygen, calcium, and nitrogen
hydrogen, oxygen, nitrogen, and carbon No. Sulfur is not one of the four most abundant elements found in living systems.
Which is the term for compounds that do not mix with water? (eText Concept 5.3) * proteins * hydrophilic * hydrogen-bonded * phospholipids * hydrophobic
hydrophobic Correct. Hydrophobic compounds are those that are insoluble in water.
The fatty acid tails of a phospholipid are _____ because they _____. (eText Concept 5.3) * hydrophobic ... have no charges to which water molecules can adhere * hydrophobic ... dissolve easily in water * hydrophobic ... consist of units assembled by dehydration reactions * hydrophilic ... consist of units assembled by dehydration reactions * hydrophilic ... are easily hydrolyzed into their monomers
hydrophobic ... have no charges to which water molecules can adhere
At which point is a scientific investigator most likely to use deductive reasoning?
in establishing a test of hypothesis.
In experimental procedures, repetition of the procedures _____.
is necessary before concluding that a given set of results is correct.
The sex hormones estrogen, progesterone, and testosterone belong to which class of molecules? (eText Concept 5.3) * proteins * lipids * amino acids * nucleic acids * carbohydrates
lipids Correct. Steroids, such as estrogen, progesterone, and testosterone, are lipids based on their insolubility in water. The molecules are characterized by a carbon skeleton consisting of four fused rings of carbon atoms.
Which of the following subatomic particles has appreciable mass and lacks a charge? (eText Concept 2.2) 1. proton 2. electron 3. element 4. molecule 5. neutron
neutron No. A molecule is not a subatomic particle. A molecule is composed of two or more atoms joined together by covalent bond(s).
A nucleotide is made of which of the following chemical components? (eText Concept 5.5) * a series of nitrogenous bases, a nucleic acid backbone, and a hexose sugar * a nitrogenous base, an amino acid, and a pentose sugar * a nitrogenous base, an amino acid, and a phosphate group * a nitrogenous base, a fatty acid, and an amino acid * a nitrogenous base, a phosphate group, and a pentose sugar
nitrogenous base, a phosphate group, and a pentose sugar Correct. Each nucleotide consists of three parts: an organic molecule, called a nitrogenous base; a 5-carbon sugar, called a pentose; and a phosphate group that serves in the phosphodiester covalent bond that forms a bridge between adjacent nucleotides.
The chemical characteristics or reactivity of an element depend mostly on the _____. (eText Concept 2.2) 1. degree to which it has more or fewer electrons than protons 2. number of protons plus the number of neutrons 3. number of electron shells present in the atoms 4. mean energy level of its electrons 5. number of electrons in its outermost shell
number of electrons in its outermost shell No. However, electrons play the major role in determining the chemical characteristics of an atom.
Some groups of elements react chemically in similar ways. For example, the chemistry of sodium and the chemistry of lithium are similar. The chemistry of chlorine and the chemistry of iodine are also similar. These similarities in chemistry result when different elements have similar _____. (eText Concept 2.2) 1. numbers of outer-shell electrons 2. atomic size 3. energy quanta per electron 4. atomic numbers 5. total numbers of electrons
numbers of outer-shell electrons No. An atom of iodine (atomic mass 130) is much larger than an atom of chlorine (atomic mass 35).
Which of the following is the major energy storage compound of plant seeds? (eText Concept 5.3) * cellulose * glycogen * lipids * amylose * oils
oils
The lipids that form the main structural component of cell membranes are _____. (eText Concept 5.3) * carbohydrates * triacylglycerols * cholesterol * proteins * phospholipids
phospholipids Correct. Phospholipids have a hydrophilic head and two hydrophobic tails. This permits the phospholipids to be arranged in a bilayer, or double layer, which forms a boundary between the cell and its external environment.
Cellulose is a _____ made of many _____. (eText Concept 5.2) *polymer ... glucose molecules * carbohydrate ... fatty acids * lipid ... triacylglycerols * protein ... amino acids * polypeptide ... monomers
polymer ... glucose molecules Correct. Cellulose is a polysaccharide and therefore a polymer, constructed from many monosaccharide glucose monomers.
in a hydrolysis reaction, _____, and in this process water is _____. (eText Concept 5.1) * a monomer is broken up into its constituent polymers ... produced * monomers are assembled to produce a polymer ... produced * monomers are assembled to produce a polymer ... consumed * a polymer is broken up into its constituent monomers ... produced * a polymer is broken up into its constituent monomers ... consumed
polymer is broken up into its constituent monomers ... consumed In hydrolysis water is utilized as a reactant; water is not a product of a hydrolysis reaction.
Which of the following lists ranks these molecules in the correct order by size? (eText Concept 5.4) * water, sucrose, glucose, protein * protein, sucrose, glucose, water * protein, water, glucose, sucrose * water, protein, sucrose, glucose * glucose, water, sucrose, protei
protein, sucrose, glucose, water Correct. In this case, the ranking is from largest to smallest.
the alpha helix and beta pleated sheet represent which level of protein structure? (eText Concept 5.4) * secondary structure * pentiary structure * tertiary structure * primary structure * quaternary structure
secondary structure
A neutral atom of chlorine has an atomic number of 17. It has _____ electrons in its third shell. (eText Concept 2.2) 1. two 2. seven 3. eight 4. 10 5. 17
seven No. Remember that the third shell can only accommodate a maximum of eight electrons.
An uncharged atom of nitrogen (atomic number = 7) has _____. (eText Concept 2.2) 1. seven protons and seven neutrons 2. seven neutrons and seven electrons 3. seven neutrons 4. seven valence electrons 5. seven protons and seven electrons
seven protons and seven electrons Correct. The atomic number is the number of protons, and this equals the number of electrons in an electrically neutral (uncharged) atom.
How many electrons would be present in the valence shell of a sulfur atom (atomic number 16, mass number 32)? (eText Concept 2.2) 1. eight electrons 2. six electrons 3. four electrons 4. two electrons 5.one electron
six electrons No. Consider the total number of electrons and their distribution in the electron shells.
In what polysaccharide form do plants store glucose to be available later as an energy source? (eText Concept 5.2) * protein * starch * glycogen * cellulose * fatty acids
starch
The polysaccharide that you are most likely to have eaten recently is _____. (eText Concept 5.2) * glucose * starch * ribose * chitin * lactose
starch Correct. Starch is a storage polysaccharide found especially in certain plant tissues.
Carbohydrates can function in which of the following ways? (eText Concept 5.2) * structural support * energy storage * information storage * enzymatic catalysis * structural support and energy storage
structural support and energy storage
The overall three-dimensional shape of a single polypeptide is called the _____. (eText Concept 5.4) * secondary structure * primary structure * tertiary structure * double helix * quaternary structure
tertiary structure
In a 1-4 glycosidic linkage, _____. (eText Concept 5.2) * one monosaccharide is bound to four others * the number 1 carbon in one monosaccharide is bound to the number 4 carbon in another monosaccharide * there are four possible isomers of the structure * the number 1 carbon in one nucleotide is bound to the number 4 carbon in another nucleotide * one glycerol molecule is bound to four fatty acids
the number 1 carbon in one monosaccharide is bound to the number 4 carbon in another monosaccharide
the "primary structure" of a protein refers to _____. (eText Concept 5.4) * interactions among the side chains or R groups of the amino acids * the α helix or β pleated sheets * the sequence of amino acids * coiling due to hydrogen bonding between amino acids * the weak aggregation of two or more polypeptide chains into one functional macromolecule
the sequence of amino acids
The energy used by most organisms for metabolism and growth ultimately comes from _____.
the sun
One characteristic shared by sucrose, lactose, and maltose is that _____. (eText Concept 5.2) * they are all disaccharides * they are all indigestible by humans * they are all polysaccharides * they all contain fructose
they are all disaccharides Correct. A disaccharide consists of two monosaccharides joined together by a glycosidic linkage.
Radioactive isotopes are useful in scientific research because _____. (eText Concept 2.2) 1. they are difficult to detect in small amounts, but living cells cannot distinguish them from the corresponding stable isotopes 2. they decay spontaneously and give off energy and subatomic particles 3.they are not readily incorporated into biological reactions 4. they can be used as tracers to follow particular atoms and molecules through metabolic pathways 5.All of the listed responses are correct.
they can be used as tracers to follow particular atoms and molecules through metabolic pathways No. Although living cells cannot distinguish radioactive isotopes from stable isotopes, radioactive isotopes are easy to detect in small amounts.
Phosphorus-32 (radioactive) has _____ than phosphorus-35 (normal). (eText Concept 2.2) 1. three more neutrons 2. three fewer neutrons 3. three fewer protons 4. three more atoms 5. three more protons
three fewer neutrons No. The radioactive isotope has the lower atomic mass.
Which of the following are pyrimidines found in the nucleic acid DNA? (eText Concept 5.5) * thymine and cytosine * guanine and cytosine * thymine and adenine * uracil and guanine * adenine and guanine
thymine and cytosine
