Without treatment, why does African sleeping sickness invariably lead to death?

Without treatment, why does African sleeping sickness invariably lead to death? The trypanosomes that cause this disease are capable of expressing...

How does killing Anopheles mosquitoes affect the Plasmodium protists?

How does killing Anopheles mosquitoes affect the Plasmodium protists? Plasmodium parasites infect humans and cause malaria. However, they must complete...

Which parasitic protist evades the host immune system by altering its surface proteins with each generation?

Which parasitic protist evades the host immune system by altering its surface proteins with each generation?  a. Paramecium caudatum b. Trypanosoma...

An example of carbon fixation is _____________.

An example of carbon fixation is _____________. a. photosynthesis b. decomposition c. phagocytosis d. parasitism Answer: a. photosynthesi...

Why might a light-sensing eyespot be ineffective for an obligate saprobe? Suggest an alternative organ for a saprobic protist.

Why might a light-sensing eyespot be ineffective for an obligate saprobe? Suggest an alternative organ for a saprobic protist. By definition, an obligate...

The chlorophyte (green algae) genera Ulva and Caulerpa both have macroscopic leaf-like and stem-like structures, but only Ulva species are considered truly multicellular. Explain why.

The chlorophyte (green algae) genera Ulva and Caulerpa both have macroscopic leaf-like and stem-like structures, but only Ulva species are considered...

What genus of protists appears to contradict the statement that unicellularity restricts cell size?

What genus of protists appears to contradict the statement that unicellularity restricts cell size? a. Dictyostelium b. Ulva c. Plasmodium d. Caulerpa Answer: d....

What is the function of the raphe in diatoms?

What is the function of the raphe in diatoms? a. locomotion b. defense c. capturing food d. photosynthesis Answer: a. locomotio...

Conjugation between two Paramecia produces ________ total daughter cells.

Conjugation between two Paramecia produces ________ total daughter cells. a. 2 b. 4 c. 8 d. 16 Answer: c. ...

Which protist group exhibits mitochondrial remnants with reduced functionality?

Which protist group exhibits mitochondrial remnants with reduced functionality? a. slime molds b. diatoms c. parabasalids d. dinoflagellates Answer: c....

Which of the following statements about the Laminaria life cycle is false?

Which of the following statements about the Laminaria life cycle is false? a. 1n zoospores form in the sporangia. b. The sporophyte is the 2n plant. c....

Which of the following statements about Paramecium sexual reproduction is false?

Which of the following statements about Paramecium sexual reproduction is false? a. The macronuclei are derived from micronuclei. b. Both mitosis...

Alternation of generations describes which of the following?

Alternation of generations describes which of the following? a. The haploid form can be multicellular; the diploid form is unicellular. b. The haploid...

Which of these locomotor organs would likely be the shortest?

Which of these locomotor organs would likely be the shortest? a. a flagellum b. a cilium c. an extended pseudopod d. a pellicle Answer: b....

Protists with the capabilities to perform photosynthesis and to absorb nutrients from dead organisms are called ______________.

Protists with the capabilities to perform photosynthesis and to absorb nutrients from dead organisms are called ______________. a. photoautotrophs b....

Protists that have a pellicle are surrounded by ______________.

Protists that have a pellicle are surrounded by ______________. a. silica dioxide b. calcium carbonate c. carbohydrates d. proteins Answer: d....

Which of these protists is believed to have evolved following a secondary endosymbiosis?

Which of these protists is believed to have evolved following a secondary endosymbiosis? a. green algae b. cyanobacteria c. red algae d. chlorarachniophytes Answer: d....

Mitochondria most likely evolved by _____________.

Mitochondria most likely evolved by _____________. a. a photosynthetic cyanobacterium b. cytoskeletal elements c. endosymbiosis d. membrane proliferation Answer: c....

Which characteristic is shared by prokaryotes and eukaryotes?

Which characteristic is shared by prokaryotes and eukaryotes?  a. cytoskeleton b. nuclear envelope c. DNA-based genome d. mitochondria Answer: c....

What event is thought to have contributed to the evolution of eukaryotes?

What event is thought to have contributed to the evolution of eukaryotes?  a. global warming b. glaciation c. volcanic activity d. oxygenation...

What evidence is there that mitochondria were incorporated into the ancestral eukaryotic cell before chloroplasts?

What evidence is there that mitochondria were incorporated into the ancestral eukaryotic cell before chloroplasts? All eukaryotic cells have mitochondria,...

Bioremediation includes _____.

Bioremediation includes _____. a. the use of prokaryotes that can fix nitrogen b. the use of prokaryotes to clean up pollutants c. the use of prokaryotes...

Synthetic compounds found in an organism but not normally produced or expected to be present in that organism are called _____.

Synthetic compounds found in an organism but not normally produced or expected to be present in that organism are called _____. a. pesticides b....

Which of these occurs through symbiotic nitrogen fixation?

Which of these occurs through symbiotic nitrogen fixation? a. The plant benefits from using an endless source of nitrogen. b. The soil benefits from...

Researchers have discovered that washing spinach with water several times does not prevent foodborne diseases due to E. coli. How can you explain this fact?

Researchers have discovered that washing spinach with water several times does not prevent foodborne diseases due to E. coli. How can you explain this...

Explain the reason why the imprudent and excessive use of antibiotics has resulted in a major global problem.

Explain the reason why the imprudent and excessive use of antibiotics has resulted in a major global problem. Antibiotics kill bacteria that are sensitive...

Which of these statements is true?

Which of these statements is true? a. An antibiotic is any substance produced by a organism that is antagonistic to the growth of prokaryotes. b....

Which of the statements about biofilms is incorrect?

Which of the statements about biofilms is incorrect? a. Biofilms are considered responsible for diseases such as cystic fibrosis. b. Biofilms produce...

A disease that is constantly present in a population is called _____.

A disease that is constantly present in a population is called _____. a. pandemic b. epidemic c. endemic d. re-emerging Answer: c. endemi...

Think about the conditions (temperature, light, pressure, and organic and inorganic materials) that you may find in a deep-sea hydrothermal vent. What type of prokaryotes, in terms of their metabolic needs (autotrophs, phototrophs, chemotrophs, etc.), would you expect to find there?

Think about the conditions (temperature, light, pressure, and organic and inorganic materials) that you may find in a deep-sea hydrothermal vent. What...

Plants use carbon dioxide from the air and are therefore called _____.

Plants use carbon dioxide from the air and are therefore called _____. a. consumers b. producers c. decomposer d. carbon fixers Answer: b....

Ammonification is the process by which _____.

Ammonification is the process by which _____. a. ammonia is released during the decomposition of nitrogen-containing organic compounds b. ammonium...

Prokaryotes that obtain their energy from chemical compounds are called _____.

Prokaryotes that obtain their energy from chemical compounds are called _____. a. phototrophs b. auxotrophs c. chemotrophs d. lithotrophs Answer: c....

Which of the following elements is not a micronutrient?

Which of the following elements is not a micronutrient?  a. boron b. calcium c. chromium d. manganese Answer: b. calciu...

Which of the following statements about the nitrogen cycle is false?

Which of the following statements about the nitrogen cycle is false? a. Nitrogen fixing bacteria exist on the root nodules of legumes and in the...

Explain the statement that both types, bacteria and archaea, have the same basic structures, but built from different chemical components.

Explain the statement that both types, bacteria and archaea, have the same basic structures, but built from different chemical components. Both bacteria...

Mention three differences between bacteria and archaea.

Mention three differences between bacteria and archaea. A possible answer is: Bacteria contain peptidoglycan in the cell wall; archaea do not. The...

The lipopolysaccharide layer (LPS) is a characteristic of the wall of ________.

The lipopolysaccharide layer (LPS) is a characteristic of the wall of ________. a. archaean cells b. Gram-negative bacteria c. bacterial prokaryotic...

Pseudopeptidoglycan is a characteristic of the walls of ________.

Pseudopeptidoglycan is a characteristic of the walls of ________. a. eukaryotic cells b. bacterial prokaryotic cells c. archaean prokaryotic cells d....

Prokaryotes stain as Gram-positive or Gram-negative because of differences in the cell _______.

Prokaryotes stain as Gram-positive or Gram-negative because of differences in the cell _______. a. wall b. cytoplasm c. nucleus d. chromosome Answer: a....

Organisms most likely to be found in extreme environments are ________.

Organisms most likely to be found in extreme environments are ________. a. fungi b. bacteria c. viruses d. archaea Answer: b. bacteri...

The cell wall is ________.

The cell wall is ________. a. interior to the cell membrane b. exterior to the cell membrane c. a part of the cell membrane d. interior or exterior,...

Which of the following consist of prokaryotic cells?

Which of the following consist of prokaryotic cells? a. bacteria and fungi b. archaea and fungi c. protists and animals d. bacteria and archaea Answer: d....

The presence of a membrane-enclosed nucleus is a characteristic of ________.

The presence of a membrane-enclosed nucleus is a characteristic of ________. a. prokaryotic cells b. eukaryotic cells c. all cells d. viruses Answer: b....

Which of the following statements is true?

Which of the following statements is true? a. Gram-positive bacteria have a single cell wall anchored to the cell membrane by lipoteichoic acid. b....

Describe briefly how you would detect the presence of a non-culturable prokaryote in an environmental sample.

Describe briefly how you would detect the presence of a non-culturable prokaryote in an environmental sample. As the organisms are non-culturable,...

Why do scientists believe that the first organisms on Earth were extremophiles?

Why do scientists believe that the first organisms on Earth were extremophiles? Because the environmental conditions on Earth were extreme: high temperatures,...

Halophiles are organisms that require________.

Halophiles are organisms that require________. a. a salt concentration of at least 0.2 M b. high sugar concentration c. the addition of halogens d....

The first organisms that oxygenated the atmosphere were

The first organisms that oxygenated the atmosphere were a. cyanobacteria b. phototrophic organisms c. anaerobic organisms d. all of the above Answer: a....

Microbial mats __________.

Microbial mats __________. a. are the earliest forms of life on Earth b. obtained their energy and food from hydrothermal vents c. are multi-layered...

The first forms of life on Earth were thought to be_________.

The first forms of life on Earth were thought to be_________. a. single-celled plants b. prokaryotes c. insects d. large animals such as dinosaurs Answer: a....

Compared to free-floating bacteria, bacteria in biofilms often show increased resistance to antibiotics and detergents. Why do you think this might be the case?

Compared to free-floating bacteria, bacteria in biofilms often show increased resistance to antibiotics and detergents. Why do you think this might...

Influenza virus is packaged in a viral envelope that fuses with the plasma membrane. This way, the virus can exit the host cell without killing it. What advantage does the virus gain by keeping the host cell alive?

Influenza virus is packaged in a viral envelope that fuses with the plasma membrane. This way, the virus can exit the host cell without killing it....

How are viroids like viruses?

How are viroids like viruses? They both replicate in a cell, and they both contain nucleic acid...

Prions are responsible for variant Creutzfeldt- Jakob Disease, which has resulted in over 100 human deaths in Great Britain during the last 10 years. How do humans obtain this disease?

Prions are responsible for variant Creutzfeldt- Jakob Disease, which has resulted in over 100 human deaths in Great Britain during the last 10 years....

Why is immunization after being bitten by a rabid animal so effective and why aren't people vaccinated for rabies like dogs and cats are?

Why is immunization after being bitten by a rabid animal so effective and why aren't people vaccinated for rabies like dogs and cats are? Rabies vaccine...

Although plant viruses cannot infect humans, what are some of the ways in which they affect humans?

Although plant viruses cannot infect humans, what are some of the ways in which they affect humans? Plant viruses infect crops, causing crop damage...

One of the first and most important targets for drugs to fight infection with HIV (a retrovirus) is the reverse transcriptase enzyme. Why?

One of the first and most important targets for drugs to fight infection with HIV (a retrovirus) is the reverse transcriptase enzyme. Why? Reverse...

Why can't dogs catch the measles?

Why can't dogs catch the measles? The virus can't attach to dog cells, because dog cells do not express the receptors for the virus and/or there is...

The first electron micrograph of a virus (tobacco mosaic virus) was produced in 1939. Before that time, how did scientists know that viruses existed if they could not see them?

The first electron micrograph of a virus (tobacco mosaic virus) was produced in 1939. Before that time, how did scientists know that viruses existed...

Which statement is true of viroids?

Which statement is true of viroids? a. They are single-stranded RNA particles. b. They reproduce only outside of the cell. c. They produce proteins. d....

Which of the following is not associated with prions?

Which of the following is not associated with prions? a. replicating shapes b. mad cow disease c. DNA d. toxic proteins Answer: c. DN...

Which of the following is NOT used to treat active viral disease?

Which of the following is NOT used to treat active viral disease? a. vaccines b. antiviral drugs c. antibiotics d. phage therapy Answer: c....

A bacteriophage can infect ________.

A bacteriophage can infect ________. a. the lungs b. viruses c. prions d. bacteria Answer: d. bacteri...

Which is true of DNA viruses?

Which is true of DNA viruses? a. They use the host cell's machinery to produce new copies of their genome. b. They all have envelopes. c. They are...

Oncogenic virus cores can be_______.

Oncogenic virus cores can be_______. a. RNA b. DNA c. neither RNA nor DNA d. either RNA or DNA Answer: d. either RNA or DN...

Which transcriptase statement is true of reverse?

Which transcriptase statement is true of reverse? a. It is a nucleic acid. b. It infects cells. c. It transcribes RNA to make DNA. d. It is a lipid. Answer: c....

Which statement is true of viral replication?

Which statement is true of viral replication? a. In the process of apoptosis, the cell survives. b. During attachment, the virus attaches at specific...

Which statement is not true of viral replication?

Which statement is not true of viral replication?  a. lysogenic cycle kills the host cell. b.There are six basic steps in the viral replication...

Viruses_______.

Viruses_______. a. all have a round shape b. cannot have a long shape c. do not maintain any shape d. vary in shape Answer: d. vary in sha...

The viral ________ plays a role in attaching a virion to the host cell.

The viral ________ plays a role in attaching a virion to the host cell. a. core b. capsid c. envelope d. both b and c Answer: d. both b and...

Which statement is true?

Which statement is true? a. A virion contains DNA and RNA. b. Viruses are acellular. c. Viruses replicate outside of the cell. d. Most viruses are...

Which of the following statements is false?

Which of the following statements is false? a. In the lytic cycle, new phage are produced and released into the environment. b. In the lysogenic cycle,...

Which of the following statements about virus structure is true?

Which of the following statements about virus structure is true? a. All viruses are encased in a viral membrane. b. The capsomere is made up of small...

Enzymes are

Enzymes are A) carbohydrates. B) lipids. C) proteins. D) nucleic acids. Answer: C) protein...

Which of the following store and transmit hereditary information?

Which of the following store and transmit hereditary information? A) carbohydrates B) lipids C) proteins D) nucleic acids Answer: D) nucleic...

Which of the following is a diverse group of hydrophobic molecules?

Which of the following is a diverse group of hydrophobic molecules? A) carbohydrates B) lipids C) proteins D) nucleic acids Answer: B) lip...

The element nitrogen is present in all of the following except

The element nitrogen is present in all of the following except A) proteins. B) nucleic acids. C) amino acids. D) DNA. E) monosaccharides. Answer: E)...

Which of the following is an example of hydrolysis?

Which of the following is an example of hydrolysis? A) the reaction of two monosaccharides, forming a disaccharide with the release of water B) the...

A new organism is discovered in the forests of Costa Rica. Scientists there determine that the polypeptide sequence of hemoglobin from the new organism has 72 amino acid differences from humans, 65 differences from a gibbon, 49 differences from a rat, and 5 differences from a frog. These data suggest that the new organism

A new organism is discovered in the forests of Costa Rica. Scientists there determine that the polypeptide sequence of hemoglobin from the new organism...

What is the structural feature that allows DNA to replicate?

What is the structural feature that allows DNA to replicate? A) sugar-phosphate backbone B) complementary pairing of the nitrogenous bases C) disulfide...

If one strand of a DNA molecule has the sequence of bases 5ʹATTGCA3ʹ, the other complementary strand would have the sequence

If one strand of a DNA molecule has the sequence of bases 5ʹATTGCA3ʹ, the other complementary strand would have the sequence A) 5ʹTAACGT3ʹ. B) 3ʹTAACGT5ʹ. C)...

In the double helix structure of nucleic acids, cytosine hydrogen bonds to

In the double helix structure of nucleic acids, cytosine hydrogen bonds to A) deoxyribose. B) ribose. C) adenine. D) thymine. E) guanine. Answer: E)...

Which of the following statements best summarizes the structural differences between DNA and RNA?

Which of the following statements best summarizes the structural differences between DNA and RNA? A) RNA is a protein, whereas DNA is a nucleic acid. B)...

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

The difference between the sugar in DNA and the sugar in RNA is that the sugar in DNA A) is a six-carbon sugar and the sugar in RNA is a five-carbon...

A double-stranded DNA molecule contains a total of 120 purines and 120 pyrimidines. This DNA molecule could be composed of

A double-stranded DNA molecule contains a total of 120 purines and 120 pyrimidines. This DNA molecule could be composed of A) 120 adenine and 120...

If a DNA sample were composed of 10% thymine, what would be the percentage of guanine?

If a DNA sample were composed of 10% thymine, what would be the percentage of guanine? A) 10 B) 20 C) 40 D) 80 E) impossible to tell from the information...

Which of the following are nitrogenous bases of the purine type?

Which of the following are nitrogenous bases of the purine type? A) cytosine and guanine B) guanine and adenine C) adenine and thymine D) thymine...

Which of the following are nitrogenous bases of the pyrimidine type?

Which of the following are nitrogenous bases of the pyrimidine type? A) guanine and adenine B) cytosine and uracil C) thymine and guanine D) ribose...

Which of the following descriptions best fits the class of molecules known as nucleotides?

Which of the following descriptions best fits the class of molecules known as nucleotides? A) a nitrogenous base and a phosphate group B) a nitrogenous...

Which of the following best describes the flow of information in eukaryotic cells?

Which of the following best describes the flow of information in eukaryotic cells? A) DNA → RNA → proteins B) RNA → proteins → DNA C) proteins → DNA...

Of the following functions, the major purpose of RNA is to

Of the following functions, the major purpose of RNA is to A) transmit genetic information to offspring. B) function in the synthesis of protein. C)...

Which of the following statements about the 5ʹ end of a polynucleotide strand of DNA is correct?

Which of the following statements about the 5ʹ end of a polynucleotide strand of DNA is correct? A) The 5ʹ end has a hydroxyl group attached to the...

DNAase is an enzyme that catalyzes the hydrolysis of the covalent bonds that join nucleotides together. What would first happen to DNA molecules treated with DNAase?

DNAase is an enzyme that catalyzes the hydrolysis of the covalent bonds that join nucleotides together. What would first happen to DNA molecules treated...

What is the term used for a protein molecule that assists in the proper folding of other proteins?

What is the term used for a protein molecule that assists in the proper folding of other proteins? A) tertiary protein B) chaperonin C) enzyme protein D)...

The function of each protein is a consequence of its specific shape. What is the term used for a change in a proteinʹs three-dimensional shape or conformation due to disruption of hydrogen bonds, disulfide bridges, or ionic bonds?

The function of each protein is a consequence of its specific shape. What is the term used for a change in a proteinʹs three-dimensional shape or conformation...

Which of the following uses the amino acid sequences of polypeptides to predict a proteinʹs three-dimensional structure?

Which of the following uses the amino acid sequences of polypeptides to predict a proteinʹs three-dimensional structure? A) X-ray crystallography B)...

Roger Kornberg used this method for elucidating the structure of RNA polymerase.

Roger Kornberg used this method for elucidating the structure of RNA polymerase. A) X-ray crystallography B) bioinformatics C) analysis of amino acid...

What method did Frederick Sanger use to elucidate the structure of insulin?

What method did Frederick Sanger use to elucidate the structure of insulin? A) X-ray crystallography B) bioinformatics C) analysis of amino acid sequence...

Altering which of the following levels of structural organization could change the function of a protein?

Altering which of the following levels of structural organization could change the function of a protein? A) primary B) secondary C) tertiary D) quaternary E)...

What would be an unexpected consequence of changing one amino acid in a protein consisting of 325 amino acids?

What would be an unexpected consequence of changing one amino acid in a protein consisting of 325 amino acids? A) The primary structure of the protein...

Misfolding of polypeptides is a serious problem in cells. Which of the following diseases are associated with an accumulation of misfolded proteins?

Misfolding of polypeptides is a serious problem in cells. Which of the following diseases are associated with an accumulation of misfolded proteins? A)...

The R group or side chain of the amino acid serine is —CH2OH. The R group or side chain of the amino acid alanine is —CH3. Where would you expect to find these amino acids in a globular protein in aqueous solution?

The R group or side chain of the amino acid serine is —CH2OH. The R group or side chain of the amino acid alanine is —CH3. Where would you expect to...

At which level of protein structure are interactions between the side chains (R groups) most important?

At which level of protein structure are interactions between the side chains (R groups) most important? A) primary B) secondary C) tertiary D) quaternary E)...

A strong covalent bond between amino acids that functions in maintaining a polypeptideʹs specific three-dimensional shape is a (an)

A strong covalent bond between amino acids that functions in maintaining a polypeptideʹs specific three-dimensional shape is a (an) A) ionic bond. B)...

The tertiary structure of a protein is the

The tertiary structure of a protein is the A) bonding together of several polypeptide chains by weak bonds. B) order in which amino acids are joined...

The α helix and the β pleated sheet are both common polypeptide forms found in which level of protein structure?

The α helix and the β pleated sheet are both common polypeptide forms found in which level of protein structure? A) primary B) secondary C) tertiary D)...

Which type of interaction stabilizes the alpha (α) helix and the beta (β) pleated sheet structures of proteins?

Which type of interaction stabilizes the alpha (α) helix and the beta (β) pleated sheet structures of proteins? A) hydrophobic interactions B) nonpolar...

What maintains the secondary structure of a protein?

What maintains the secondary structure of a protein? A) peptide bonds B) hydrogen bonds C) disulfide bonds D) ionic bonds E) phosphodiester bonds Answer: B)...

Which bonds are created during the formation of the primary structure of a protein?

Which bonds are created during the formation of the primary structure of a protein? A) peptide bonds B) hydrogen bonds C) disulfide bonds D) phosphodiester...

How many different kinds of polypeptides, each composed of 12 amino acids, could be synthesized using the 20 common amino acids?

How many different kinds of polypeptides, each composed of 12 amino acids, could be synthesized using the 20 common amino acids? A) 4^12 B) 12^20 C)...

Upon chemical analysis, a particular polypeptide was found to contain 100 amino acids. How many peptide bonds are present in this protein?

Upon chemical analysis, a particular polypeptide was found to contain 100 amino acids. How many peptide bonds are present in this protein? A) 101 B)...

Dehydration reactions are used in forming which of the following compounds?

Dehydration reactions are used in forming which of the following compounds? A) triacylglycerides B) polysaccharides C) proteins D) A and C only E)...

Polysaccharides, lipids, and proteins are similar in that they

Polysaccharides, lipids, and proteins are similar in that they A) are synthesized from monomers by the process of hydrolysis. B) are synthesized from...

The bonding of two amino acid molecules to form a larger molecule requires which of the following?

The bonding of two amino acid molecules to form a larger molecule requires which of the following? A) removal of a water molecule B) addition of a...

There are 20 different amino acids. What makes one amino acid different from another?

There are 20 different amino acids. What makes one amino acid different from another? A) different carboxyl groups attached to an alpha (α) carbon B)...

The bonding of two amino acid molecules to form a larger molecule requires

The bonding of two amino acid molecules to form a larger molecule requires A) the release of a water molecule. B) the release of a carbon dioxide...

All of the following contain amino acids except

All of the following contain amino acids except A) hemoglobin. B) cholesterol. C) antibodies. D) enzymes. E) insulin. Answer: B) cholester...

Why are human sex hormones considered to be lipids?

Why are human sex hormones considered to be lipids? A) They are essential components of cell membranes. B) They are steroids, which are not soluble...

The hydrogenation of vegetable oil results in which of the following?

The hydrogenation of vegetable oil results in which of the following? A) saturated fats and unsaturated fats with trans double bonds B) an increased...

Large organic molecules are usually assembled by polymerization of a few kinds of simple subunits. Which of the following is an exception to this statement?

Large organic molecules are usually assembled by polymerization of a few kinds of simple subunits. Which of the following is an exception to this statement? A)...

Which of the following is true regarding saturated fatty acids?

Which of the following is true regarding saturated fatty acids? A) They are the predominant fatty acid in corn oil. B) They have double bonds between...

What is a triacylglycerol?

What is a triacylglycerol? A) a protein with tertiary structure B) a lipid made with three fatty acids and glycerol C) a lipid that makes up much...

Which of the following statements is false for the class of biological molecules known as lipids?

Which of the following statements is false for the class of biological molecules known as lipids? A) They are soluble in water. B) They are an important...

A molecule with the formula C18H36O2 is probably a

A molecule with the formula C18H36O2 is probably a A) carbohydrate. B) fatty acid. C) protein. D) nucleic acid. E) hydrocarbon. Answer: B)...

All of the following statements concerning saturated fats are true except

All of the following statements concerning saturated fats are true except A) They are more common in animals than in plants. B) They have multiple...

Humans can digest starch but not cellulose because

Humans can digest starch but not cellulose because A) the monomer of starch is glucose, while the monomer of cellulose is galactose. B) humans have...

Which of the following is true of cellulose?

Which of the following is true of cellulose? A) It is a polymer composed of sucrose monomers. B) It is a storage polysaccharide for energy in plant...

Which of the following is true of both starch and cellulose?

Which of the following is true of both starch and cellulose? A) They are both polymers of glucose. B) They are geometric isomers of each other. C)...

All of the following are polysaccharides except

All of the following are polysaccharides except A) glycogen B) starch C) chitin D) cellulose E) amylopectin Answer: A) glycoge...

Lactose, a sugar in milk, is composed of one glucose molecule joined by a glycosidic linkage to one galactose molecule. How is lactose classified?

Lactose, a sugar in milk, is composed of one glucose molecule joined by a glycosidic linkage to one galactose molecule. How is lactose classified? A)...

A molecule with the chemical formula C6H12O6 is probably a

A molecule with the chemical formula C6H12O6 is probably a A) carbohydrate. B) lipid. C) monosaccharide D) A and B only. E) A, B, and C. Answer: E)...

On food packages, to what does the term ʺinsoluble fiberʺ refer?

On food packages, to what does the term ʺinsoluble fiberʺ refer? A) cellulose B) polypeptides C) starch D) amylopectin E) chitin Answer: A)...

The enzyme amylase can break glycosidic linkages between glucose monomers only if the monomers are the α form. Which of the following could amylase break down?

The enzyme amylase can break glycosidic linkages between glucose monomers only if the monomers are the α form. Which of the following could amylase...

The molecular formula for glucose is C6H12O6. What would be the molecular formula for a molecule made by linking three glucose molecules together by dehydration reactions?

The molecular formula for glucose is C6H12O6. What would be the molecular formula for a molecule made by linking three glucose molecules together by...

Which of the following polymers contain nitrogen?

Which of the following polymers contain nitrogen? A) starch B) glycogen C) cellulose D) chitin E) amylopectin Answer: D) chiti...

Which of the following best summarizes the relationship between dehydration reactions and hydrolysis?

Which of the following best summarizes the relationship between dehydration reactions and hydrolysis? A) Dehydration reactions assemble polymers,...

How many molecules of water are needed to completely hydrolyze a polymer that is 11 monomers long?

How many molecules of water are needed to completely hydrolyze a polymer that is 11 monomers long? A) 12 B) 11 C) 10 D) 9 E) 8 Answer: C) ...

What is the chemical mechanism by which cells make polymers from monomers?

What is the chemical mechanism by which cells make polymers from monomers? A) phosphodiester linkages B) hydrolysis C) dehydration reactions D) ionic...

Which of the following is not a polymer?

Which of the following is not a polymer? A) glucose B) starch C) cellulose D) chitin E) DNA Answer: A) glucos...

For this pair of items, choose the option that best describes their relationship.

For this pair of items, choose the option that best describes their relationship. (A) The number of purines in the DNA strand 5ʹ-AAGAGGAGAAA-3ʹ (B)...

For this pair of items, choose the option that best describes their relationship.

For this pair of items, choose the option that best describes their relationship. (A) The probability that amino acids with nonpolar side chains are...

For this pair of items, choose the option that best describes their relationship.

For this pair of items, choose the option that best describes their relationship. (A) The number of cis double bonds in saturated fatty acids (B) The...

For this pair of items, choose the option that best describes their relationship.

For this pair of items, choose the option that best describes their relationship. (A) The probability of finding chitin in fungal cell walls (B) The...

For this pair of items, choose the option that best describes their relationship.

For this pair of items, choose the option that best describes their relationship. (A) The number of alpha glucose 1-4 linkages in cellulose (B) The...

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 20 mL of the HCL and 20 mL of the NaOH. After complete stirring, the pH of the mixture will be

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...

You have two beakers; one contains pure water, the other contains pure methanol (wood alcohol). The covalent bonds of methanol molecules are nonpolar, so there are no hydrogen bonds among methanol molecules. You pour crystals of table salt (NaCl) into each beaker. Predict what will happen.

You have two beakers; one contains pure water, the other contains pure methanol (wood alcohol). The covalent bonds of methanol molecules are nonpolar,...

Equal volumes of vinegar from a freshly-opened bottle are added to each of the following solutions. After complete mixing, which of the mixtures will have the highest pH?

Equal volumes of vinegar from a freshly-opened bottle are added to each of the following solutions. After complete mixing, which of the mixtures will...

A 100 mL beaker contains 10 mL of NaOH solution at pH = 13. A technician carefully pours into the beaker, 10 mL of HCl at pH = 1. Which of the following statements correctly describes the results of this mixing?

A 100 mL beaker contains 10 mL of NaOH solution at pH = 13. A technician carefully pours into the beaker, 10 mL of HCl at pH = 1. Which of the following...

Carbon dioxide (CO2) is readily soluble in water, according to the equation CO2 + H2O → H2CO3. Carbonic acid (H2CO3) is a weak acid. Respiring cells release CO2. What prediction can we make about the pH of blood as that blood first comes in contact with respiring cells?

Carbon dioxide (CO2) is readily soluble in water, according to the equation CO2 + H2O → H2CO3. Carbonic acid (H2CO3) is a weak acid. Respiring cells...

Pure, freshly-distilled water has a pH of 7. This means that

Pure, freshly-distilled water has a pH of 7. This means that A) there are no H+ ions in the water. B) there are no OH- ions in the water. C) the concentration...

Consider two solutions: solution X has a pH of 4; solution Y has a pH of 7. From this information, we can reasonably conclude that

Consider two solutions: solution X has a pH of 4; solution Y has a pH of 7. From this information, we can reasonably conclude that A) solution Y has...

Research indicates that acid precipitation can damage living organisms by

Research indicates that acid precipitation can damage living organisms by A) buffering aquatic systems such as lakes and streams. B) decreasing the...

Assume that acid rain has lowered the pH of a particular lake to pH 4.0. What is the hydroxyl ion concentration of this lake?

Assume that acid rain has lowered the pH of a particular lake to pH 4.0. What is the hydroxyl ion concentration of this lake? A) 1 × 10-10 mol of...

Buffers are substances that help resist shifts in pH by

Buffers are substances that help resist shifts in pH by A) releasing H+ in acidic solutions. B) donating H+ to a solution when they have been depleted. C)...

Which of the following statements is true about buffer solutions?

Which of the following statements is true about buffer solutions? A) They maintain a constant pH when bases are added to them but not when acids are...

One liter of a solution pH 9 has how many more hydroxyl ions (OH-) than 1 L of a solution of pH 4?

One liter of a solution pH 9 has how many more hydroxyl ions (OH-) than 1 L of a solution of pH 4? A) 5 times more B) 100 times more C) 1,000 times...

One liter of a solution of pH 2 has how many more hydrogen ions (H+) than 1 L of a solution of pH 6?

One liter of a solution of pH 2 has how many more hydrogen ions (H+) than 1 L of a solution of pH 6? A) 4 times more B) 400 times more C) 4,000 times...

If the pH of a solution is increased from pH 5 to pH 7, it means that the

If the pH of a solution is increased from pH 5 to pH 7, it means that the A) concentration of H+ is twice (2X) what it was at pH 5. B) concentration...

If the pH of a solution is decreased from 9 to 8, it means that the

If the pH of a solution is decreased from 9 to 8, it means that the A) concentration of H+ has decreased to one-tenth (1/10) what it was at pH 9. B)...

Which of the following solutions has the greatest concentration of hydroxyl ions [OH-]?

Which of the following solutions has the greatest concentration of hydroxyl ions [OH-]? A) lemon juice at pH 2 B) vinegar at pH 3 C) tomato juice...

Which of the following solutions has the greatest concentration of hydrogen ions [H +]?

Which of the following solutions has the greatest concentration of hydrogen ions [H +]? A) gastric juice at pH 2 B) vinegar at pH 3 C) tomato juice...

What is the pH of a solution with a hydrogen ion [H+] concentration of 10-8 M?

What is the pH of a solution with a hydrogen ion [H+] concentration of 10-8 M? A) pH 2 B) pH 4 C) pH 6 D) pH 8 E) pH 10 Answer: D) pH ...

What is the pH of a solution with a hydroxyl ion [OH-] concentration of 10-12 M?

What is the pH of a solution with a hydroxyl ion [OH-] concentration of 10-12 M? A) pH 2 B) pH 4 C) pH 10 D) pH 12 E) pH 14 Answer: A) pH ...

A solution contains 0.0000001(10-7) moles of hydroxyl ions [OH-] per liter. Which of the following best describes this solution?

A solution contains 0.0000001(10-7) moles of hydroxyl ions [OH-] per liter. Which of the following best describes this solution? A) acidic: H+ acceptor B)...

A given solution contains 0.0001(10-4) moles of hydrogen ions [H+] per liter. Which of the following best describes this solution?

A given solution contains 0.0001(10-4) moles of hydrogen ions [H+] per liter. Which of the following best describes this solution? A) acidic: H+ acceptor B)...

Which of the following statements is completely correct?

Which of the following statements is completely correct? A) H2CO3 is a weak acid, and NaOH is a weak base (alkali). B) H2CO3 is a strong acid, and...

Which of the following ionizes completely in solution and is considered to be a strong base (alkali)?

Which of the following ionizes completely in solution and is considered to be a strong base (alkali)? A) NaCl B) HCl C) NH3 D) H2CO3 E) NaOH Answer: E)...

Which of the following ionizes completely in solution and is considered to be a strong acid?

Which of the following ionizes completely in solution and is considered to be a strong acid? A) NaOH B) HCl C) NH3 D) H2CO3 E) CH3COOH Answer: B)...

You have a freshly-prepared 1M solution of glucose in water. You carefully pour out a 100 mL sample of that solution. How many glucose molecules are included in that 100 mL sample?

You have a freshly-prepared 1M solution of glucose in water. You carefully pour out a 100 mL sample of that solution. How many glucose molecules are...

The molecular weight of water is 18 daltons. What is the molarity of 1 liter of pure water?

The molecular weight of water is 18 daltons. What is the molarity of 1 liter of pure water? A) 55.6M B) 18M C) 37M D) 0.66M E) 1.0M Answer: A)...

You have a freshly-prepared 0.1M solution of glucose in water. Each liter of this solution contains how many glucose molecules?

You have a freshly-prepared 0.1M solution of glucose in water. Each liter of this solution contains how many glucose molecules? A) 6.02 × 1023 B)...

The molecular mass of glucose (C6H12O6) is 180 g. Which of the following procedures should you carry out to make a 0.5 M solution of glucose?

The molecular mass of glucose (C6H12O6) is 180 g. Which of the following procedures should you carry out to make a 0.5 M solution of glucose? A) Dissolve...

The molecular mass of glucose is 180 g. Which of the following procedures should you carry out to make a 1 M solution of glucose?

The molecular mass of glucose is 180 g. Which of the following procedures should you carry out to make a 1 M solution of glucose? A) Dissolve 1 g...

When an ionic compound such as sodium chloride (NaCl) is placed in water the component atoms of the NaCl crystal dissociate into individual sodium ions (Na+) and chloride ions (Cl-). In contrast, the atoms of covalently bonded molecules (e.g., glucose, sucrose, glycerol) do not generally dissociate when placed in aqueous solution. Which of the following solutions would be expected to contain the greatest number of particles (molecules or ions)?

When an ionic compound such as sodium chloride (NaCl) is placed in water the component atoms of the NaCl crystal dissociate into individual sodium ions...

How many molecules of glucose (C6H2O6 molecular mass =180 daltons) would be present in one mole of glucose?

How many molecules of glucose (C6H2O6 molecular mass =180 daltons) would be present in one mole of glucose? A) 24 B) 342 C) 23 × 1014 D) 180 × 1014 E)...

How many molecules of glycerol (C3H8O3) would be present in 1 L of a 1 M glycerol solution?

How many molecules of glycerol (C3H8O3) would be present in 1 L of a 1 M glycerol solution? A) 1 B) 14 C) 92 D) 1 × 107 E) 6.02 × 1023 Answer: E)...

One mole (mol) of a substance is

One mole (mol) of a substance is A) 6.02 × 1023 molecules of the substance. B) 1 g of the substance dissolved in 1 L of solution. C) the largest amount...

Hydrophobic substances such as vegetable oil are

Hydrophobic substances such as vegetable oil are A) nonpolar substances that repel water molecules. B) nonpolar substances that have an attraction...

Why does ice float in liquid water?

Why does ice float in liquid water? A) The liquid water molecules have more kinetic energy and thus support the ice. B) The ionic bonds between the...

At what temperature is water at its densest?

At what temperature is water at its densest? A) 0°C B) 4°C C) 32°C D) 100°C E) 212°C Answer: B) 4°...

Temperature usually increases when water condenses. Which behavior of water is most directly responsible for this phenomenon?

Temperature usually increases when water condenses. Which behavior of water is most directly responsible for this phenomenon? A) the change in density...

Which type of bond must be broken for water to vaporize?

Which type of bond must be broken for water to vaporize? A) ionic bonds B) nonpolar covalent bonds C) polar covalent bonds D) hydrogen bonds E) covalent...

Waterʹs high specific heat is mainly a consequence of the

Waterʹs high specific heat is mainly a consequence of the A) small size of the water molecules. B) high specific heat of oxygen and hydrogen atoms. C)...

The nutritional information on a cereal box shows that one serving of a dry cereal has 200 kilocalories. If one were to burn one serving of the cereal, the amount of heat given off would be sufficient to raise the temperature of 20 kg of water how many degrees Celsius?

The nutritional information on a cereal box shows that one serving of a dry cereal has 200 kilocalories. If one were to burn one serving of the cereal,...

Which of the following statements correctly defines a kilocalorie?

Which of the following statements correctly defines a kilocalorie? A) the amount of heat required to raise the temperature of 1 g of water by 1°F B)...

Which of the following takes place as an ice cube cools a drink?

Which of the following takes place as an ice cube cools a drink? A) Molecular collisions in the drink increase. B) Kinetic energy in the drink decreases. C)...

Which of the following effects is produced by the high surface tension of water?

Which of the following effects is produced by the high surface tension of water? A) Lakes donʹt freeze solid in winter, despite low temperatures. B)...

What gives rise to the cohesiveness of water molecules?

What gives rise to the cohesiveness of water molecules? A) hydrophobic interactions B) nonpolar covalent bonds C) ionic bonds D) hydrogen bonds E)...

Water is able to form hydrogen bonds because

Water is able to form hydrogen bonds because A) oxygen has a valence of 2. B) the water molecule is shaped like a tetrahedron. C) the bonds that hold...

An example of a hydrogen bond is the bond between

An example of a hydrogen bond is the bond between A) C and H in methane (CH4). B) the H of one water molecule and the O of another water molecule. C)...

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?

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...

In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by

In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by A) hydrogen bonds. B) nonpolar covalent bonds. C) polar covalent...

Based on Figure 7.19 in your textbook, which of these experimental treatments would increase the rate of sucrose transport into the cell?

Based on Figure 7.19 in your textbook, which of these experimental treatments would increase the rate of sucrose transport into the cell? A) decreasing...

Which of the following processes includes all others?

Which of the following processes includes all others? A) osmosis B) diffusion of a solute across a membrane C) facilitated diffusion D) passive transport E) transport...

Which of the following factors would tend to increase membrane fluidity?

Which of the following factors would tend to increase membrane fluidity? A) a greater proportion of unsaturated phospholipids B) a greater proportion...

According to the fluid mosaic model of membrane structure, proteins of the membrane are mostly

According to the fluid mosaic model of membrane structure, proteins of the membrane are mostly A) spread in a continuous layer over the inner and...

In what way do the membranes of a eukaryotic cell vary?

In what way do the membranes of a eukaryotic cell vary? A) Phospholipids are found only in certain membranes. B) Certain proteins are unique to each...

In receptor-mediated endocytosis, receptor molecules initially project to the outside of the cell. Where do they end up after endocytosis?

In receptor-mediated endocytosis, receptor molecules initially project to the outside of the cell. Where do they end up after endocytosis? A) on the...

The difference between pinocytosis and receptor-mediated endocytosis is that

The difference between pinocytosis and receptor-mediated endocytosis is that A) pinocytosis brings only water into the cell, but receptor-mediated...

Familial hypercholesterolemia is characterized by which of the following?

Familial hypercholesterolemia is characterized by which of the following? A) defective LDL receptors on the cell membranes B) poor attachment of...

White blood cells engulf bacteria through what process?

White blood cells engulf bacteria through what process? A) exocytosis B) phagocytosis C) pinocytosis D) osmosis E) receptor-mediated exocytosis ...

An organism with a cell wall would have the most difficulty doing which process?

An organism with a cell wall would have the most difficulty doing which process? A) diffusion B) osmosis C) active transport D) phagocytosis E) facilitated...

Several seriously epidemic viral diseases of earlier centuries were then incurable because they resulted in severe dehydration due to vomiting and diarrhea. Today they are usually not fatal because we have developed which of the following?

Several seriously epidemic viral diseases of earlier centuries were then incurable because they resulted in severe dehydration due to vomiting and diarrhea....

Proton pumps are used in various ways by members of every kingdom of organisms. What does this most probably mean?

Proton pumps are used in various ways by members of every kingdom of organisms. What does this most probably mean? A) Proton pumps must have evolved...

The sodium-potassium pump in animal cells requires cytoplasmic ATP to pump ions across the plasma membrane. When the proteins of the pump are first synthesized in the rough ER, what side of the ER membrane will the ATP binding site be on?

The sodium-potassium pump in animal cells requires cytoplasmic ATP to pump ions across the plasma membrane. When the proteins of the pump are first...

What mechanisms do plants use to load sucrose produced by photosynthesis into specialized cells in the veins of leaves?

What mechanisms do plants use to load sucrose produced by photosynthesis into specialized cells in the veins of leaves? A) an electrogenic pump B) a...

Ions diffuse across membranes down their

Ions diffuse across membranes down their A) chemical gradients. B) concentration gradients. C) electrical gradients. D) electrochemical gradients. E) A...

The movement of potassium into an animal cell requires

The movement of potassium into an animal cell requires A) low cellular concentrations of sodium. B) high cellular concentrations of potassium. C) an...

If a membrane protein in an animal cell is involved in the cotransport of glucose and sodium ions into the cell, which of the following is most likely true?

If a membrane protein in an animal cell is involved in the cotransport of glucose and sodium ions into the cell, which of the following is most likely...

The sodium-potassium pump is called an electrogenic pump because it

The sodium-potassium pump is called an electrogenic pump because it A) pumps equal quantities of Na+ and K+ across the membrane. B) pumps hydrogen...

In most cells, there are electrochemical gradients of many ions across the plasma membrane even though there are usually only one or two electrogenic pumps present in the membrane. The gradients of the other ions are most likely accounted for by

In most cells, there are electrochemical gradients of many ions across the plasma membrane even though there are usually only one or two electrogenic...

What is the voltage across a membrane called?

What is the voltage across a membrane called? A) water potential B) chemical gradient C) membrane potential D) osmotic potential E) electrochemical...

Glucose diffuses slowly through artificial phospholipid bilayers. The cells lining the small intestine, however, rapidly move large quantities of glucose from the glucose-rich food into their glucose-poor cytoplasm. Using this information, which transport mechanism is most probably functioning in the intestinal cells?

Glucose diffuses slowly through artificial phospholipid bilayers. The cells lining the small intestine, however, rapidly move large quantities of glucose...

What are the membrane structures that function in active transport?

What are the membrane structures that function in active transport? A) peripheral proteins B) carbohydrates C) cholesterol D) cytoskeleton filaments E) integral...

Which of the following membrane activities require energy from ATP hydrolysis?

Which of the following membrane activities require energy from ATP hydrolysis? A) facilitated diffusion. B) movement of water into a cell C) Na+ ions...