Bio 100 Chapter 2 Questions

Glucose (a monosaccharide) has the molecular formula C6H12O6. How many carbon atoms are in each glucose molecule?

A.) 1 B.) 4 C.) 5 D.) 6 E.) 3 -Answer D

What is the relationship between acids, bases, and hydroxide ions?

A.) Acids contain only hydroxide ions, whereas bases contain no hydroxide ions. B.) Acids contain no hydroxide ions, whereas bases contain only hydroxide ions. C.) Acids contain relatively few hydroxide ions, whereas bases contain excess hydroxide ions. D.) Acids contain excess hydroxide ions, whereas bases contain relatively few hydroxide ions. E.) Acids strengthen and bases weaken as hydroxide concentration increases. -Answer C

How do RNA and DNA molecules differ? Select the TWO answers that are correct.

A.) Adenine is used in RNA, whereas cytosine is used in DNA. B.) Uracil is used in RNA, whereas thymine is used in DNA. C.) RNA has one fatty acid chain, whereas DNA has two of them. D.) RNA contains sugars in its backbone, whereas DNA does not. E.) RNA is single-stranded, whereas DNA is double-stranded. -Answer B,E

When an atom loses an electron, what happens?

A.) Atoms cannot lose electrons. B.) It becomes positively charged. C.) It becomes neutral. D.) It becomes negatively charged. E.) Nothing happens. -Answer B

Which of the following statements about carbon is FALSE?

A.) Carbon can form inorganic molecules. B.) Soil samples containing carbon must contain life. C.) Carbon can bond with up to four elements at one time. D.) Carbon is an important element in organic molecules. E.) Covalent bonds allow carbon to share electrons with other elements. -Answer B

Where are the protons, neutrons, and electrons located in an atom?

A.) Electrons and neutrons are located in orbitals, and protons are located in the nucleus. B.) Protons, electrons, and neutrons are located in the nucleus, and energy is located in orbitals. C.) Protons and neutrons are located in the nucleus, and electrons are located in orbitals. D.) Electrons and neutrons are located in the nucleus, and protons are located in orbitals. E.) Protons and electrons are located in the nucleus, and neutrons are located in orbitals. -Answer C

What hypotheses have been proposed to explain how prions evolve? Select the TWO answers that are correct.

A.) Environmental changes cause some prions to break into small segments that may be better able than larger prions to survive and reproduce in the new environment. B.) Prions respond to environmental changes by bonding with other prion variants in the population and potentially forming new variants able to handle the change. C.) When the environment changes, one of the less common variants in a prion population may be able to better spread and become the dominant type of prion. D.) Changes in the environment change the shape of some prions, possibly producing a variant that is better able to tolerate the change than the original type of prion. -Answer C,D

Why do salt crystals form in a pan of seawater from which the water has been evaporated?

A.) In the absence of water, sodium and chloride form hydrogen bonds and aggregate into crystals. B.) In the absence of water, sodium and chloride share electrons in a stable bond that permits crystal formation. C.) In the absence of water, sodium and chloride form covalent bonds and aggregate into crystals. D.) In the absence of water, chloride donates electrons to sodium and the compounds aggregate into crystals. E.) In the absence of water, sodium and chloride form ionic bonds and aggregate into crystals. -Answer E

What makes ice less dense than liquid water?

A.) Ionic bonds between water molecules expand when solid. B.) Covalent bonds within water molecules expand when solid. C.) Nuclear forces form expansive crystals as freezing occurs. D.) Hydrogen bonds between water molecules expand when solid. E.) Hydrogen donates electrons to oxygen as freezing occurs. -Answer D

Why is the phospholipid bilayer important to cell survival? Select the TWO answers that are correct.

A.) It maintains homeostasis by forming an insulating layer around the cell. B.) It separates the cellular environment from the external environment. C.) It blocks small, nonpolar molecules from entering the cell and harming it. D.) It anchors nucleotides together as they form molecules of DNA. E.) It acts as a barrier for some, but not all, molecules on either side of it. -Answer B,E

What must the probe sent to Europa be able to do in order to effectively detect life on this world? Select the TWO answers that are correct.

A.) It must be able to detect electrical currents as low as 1 amp coursing across a sample. B.) It must be able to detect as little as a picomole of organic material in a sample. C.) It must be able to detect as few as 100 cells in a milliliter of water. D.) It must be able to detect oxygen levels in the atmosphere as low as one part per million. -Answer B,C

How are lipids unique when compared to other macromolecule groups?

A.) Lipids do not contain monomers and they are comprised of compounds. B.) Lipids are hydrophilic. C.) Lipids are water-soluble. D.) Lipids are not polymers. E.) Lipids are comprised of structurally distinct compounds. -Answer A

Based on the information in the podcast, ocean planets are prime targets in the search for life. However, in the book chapter scientists are also searching Mars for life, even though Mars is not an ocean planet. Why is Mars still considered to be a good candidate in the search for extraterrestrial life? Select the TWO answers that are correct.

A.) Martian soil releases carbon dioxide under conditions that could support life. B.) There are signs that Mars once had liquid water on its surface. C.) Fossil cyanobacteria have been found in rock samples from Mars. D.) Some photos suggest that there are underground stores of water on Mars. -Answer B,D

How do triglycerides and phospholipids differ? Select the TWO answers that are correct.

A.) Phospholipids store energy, whereas triglycerides are cell membrane components. B.) Phospholipids are saturated with hydrogens, whereas triglycerides are unsaturated. C.) Phospholipids have ribose in place of the deoxyribose used in triglycerides. D.) Phospholipids have two fatty acid tails, whereas triglycerides have three. E.) Phospholipids have a hydrophilic phosphate group in place of one fatty acid tail. -Answer D,E

_____ make up the nucleus of an atom, whereas _____ surround the nucleus.

A.) Protons and neutrons; electrons B.) Neutrons and electrons; neutrons C.) Neutrons; protons D.) Electrons; neutrons E.) Protons; electrons -Answer A

Which of the following does NOT give researchers hope that life may exist on Mars?

A.) Rovers have captured images of bacterial cells within rocks. B.) Life on Earth uses macromolecule manipulations to survive in unique environments. C.) Life on Earth adapted to extreme conditions. D.) Versions of life may come in a form that does not contain all the hallmarks of life, such as viruses. E.) Life on Earth survives in extreme conditions. -Answer A

Why is the phospholipid bilayer considered semipermeable?

A.) The hydrophobic tails act as a barrier to nonpolar molecules. B.) The bilayer is a barrier to some, but not all, substances on either side of it. C.) Small, nonpolar molecules do not pass through the phospholipid bilayer. D.) Large molecules can only pass through the layer of hydrophilic phospholipids. E.) The bilayer is completely nonpolar, which prevents some molecules from passing. -Answer B

What happened when researchers added 475 molecules of water to their experiment?

A.) The ice melts completely. B.) Complete ice crystals formed. C.) The ice began to thaw. D.) Water began to form ice crystals. -Answer B

How does the molecular structure of a water molecule affect its polarity?

A.) The oxygen has a partial negative charge and the hydrogens have a partial positive charge, yielding a weakly polar water molecule that can form hydrogen bonds. B.) The oxygen donates an electron to each hydrogen, yielding a positively charged oxygen and two negatively charged hydrogens that can form hydrogen bonds. C.) The oxygen has a partial positive charge and the hydrogens have a partial negative charge, yielding a weakly polar water molecule that can form hydrogen bonds. D.) The oxygen and hydrogen rapidly exchange electrons in their outermost energy shells, producing structures that can form hydrogen bonds. E.) The oxygen takes an electron from each hydrogen, yielding a negatively charged oxygen and two positively charged hydrogens that can form hydrogen bonds. -Answer A

How do prions cause disease?

A.) They link separate proteins together in the brain, forming clumps that block blood flow and cause nearby brain tissue to degenerate. B.) They replace the DNA in nerve cells with prion DNA, making the nerve cells in the brain produce more cells thus forming a brain tumor. C.) They cause properly folded proteins to fold incorrectly, creating more prions which collect in nerve tissue and cause brain damage. D.) They highjack the DNA replication process of a brain cell in order to reproduce, spreading to other cells when infected cells lyse. -Answer C

How does water dissolve table salt?

A.) Water is a polar molecule that disrupts hydrogen bonds between sodium and chloride. B.) Water is a polar molecule that takes electrons from sodium chloride. C.) Water is a nonpolar molecule that breaks the ionic bonds between sodium and chloride. D.) Water is a nonpolar molecule that dissolves covalent bonds between sodium and chloride. E.) Water is a polar molecule that disrupts ionic bonds between sodium and chloride. -Answer E

How does light interact differently with water and with ice?

A.) Water warms faster when exposed to light than ice does. B.) Water and ice absorb different frequencies of light. C.) Water absorbs light whereas ice crystals reflect it. D.) Water reflects more light than ice does. -Answer B

Polar bears rely on Arctic ice sheets and icebergs on the surface of water as a part of their habitat. How would the habitat of polar bears be affected if solid water was more dense than liquid water?

A.) Water would be unable to freeze at all, causing the total loss of polar bear habitat. B.) Water would stay liquid over a wider temperature range, limiting ice formation. C.) Permanent ice would form on the surface, creating more habitat for polar bears. D.) Ice would sink rather than float, so there would be no ice sheets or ice bergs. E.) Water would become polar, causing it to freeze more solidly and melt less easily. -Answer D

What characteristics make a particular molecule organic? Select the TWO answers that are correct.

A.) a carbon backbone B.) presence of carbon C.) a carbon-oxygen bond D.) a carbon-nitrogen bond E.) a carbon-hydrogen bond -Answer A,E

Which of the following are most likely to dissolve in olive oil?

A.) a nonpolar molecule B.) both nonpolar and hydrophilic molecules C.) a hydrophilic molecule D.) both nonpolar and polar molecules E.) a polar molecule -Answer A

Which statement describes a hydrogen bond between two water molecules?

A.) a weak bond in which the oxygen atom of one molecule takes an electron away from the hydrogen atom of another water molecule B.) a weak bond in which the oxygen atom of one molecule stably shares electrons with the hydrogen atom of another water molecule C.) a weak bond in which the oxygen atom of one molecule donates an electron to the hydrogen atom of another water molecule D.) a weak bond between the slightly negative oxygen atom of one water molecule and the slightly positive hydrogen atoms of another water molecule E.) a weak bond between the slightly positive oxygen atom of one water molecule and the slightly negative hydrogen atoms of another water molecule -Answer D

The "stickiness" of water results from the ______________ bonding of water molecules.

A.) acidic B.) hydrophobic C.) ionic D.) covalent E.) hydrogen -Answer E

Olive oil is _______________ because _____________________.

A.) both hydrophilic and hydrophobic; it interacts with water and oil B.) hydrophobic; it interacts with water C.) hydrophilic; it interacts with water D.) hydrophobic; it does not interact with water E.) hydrophilic; it does not interact with water -Answer D

What are the four types of organic molecules that make up all living things on Earth?

A.) carbon, hydrogen, oxygen, sulfur B.) lipids, nucleic acids, carbohydrates, proteins C.) carbohydrates, proteins, sugars, lipids D.) carbohydrates, lipids, fats, nucleic acids E.) atoms, elements, matter, carbon -Answer B

Which substances have an alkaline pH? Select the TWO answers that are correct.

A.) coffee B.) orange juice C.) battery acid D.) baking soda E.) drain cleaner -Answer D,E

As an acidic compound dissolves in water, the pH of the water _______.

A.) decreases B.) increases C.) remains neutral D.) becomes basic E.) does not change -Answer A

Which part of an atom forms covalent bonds with other atoms?

A.) electrons in the innermost energy shell B.) neutrons in the outermost energy shell C.) electrons in the outermost energy shell D.) protons in the outermost energy shell E.) protons in the innermost energy shell -Answer C

What characteristics make a world a prime candidate to potentially harbor life? Select the TWO answers that are correct.

A.) evidence of meteor impacts B.) the presence of liquid water C.) having oxygen in the atmosphere D.) being geologically active -Answer B,D

Humans' ability to shiver is an attempt to increase the body's internal temperature and maintain _______.

A.) homeostasis B.) energy C.) growth D.) carbon dioxide E.) stimuli -Answer A

One argument explaining why viruses are not living is that viruses depend on the cells of other living creatures in order to multiply. Which characteristics of life does this argument use? Select the TWO answers that are correct.

A.) homeostasis B.) respond to stimuli C.) growth D.) reproduction E.) use energy -Answer C,D

Which part of the cell membrane acts as a barrier to hydrophilic molecules entering the cell?

A.) hydrophilic tails B.) hydrophobic tails C.) hydrophilic heads D.) hydrophobic heads and tails E.) hydrophobic heads -Answer B

The bond between the oxygen atom and a hydrogen atom in a water molecule is a(n) ___________ bond)

A.) hydrophobic B.) ionic C.) noncovalent D.) covalent E.) hydrogen -Answer D

What is another possible application for the experimental techniques scientists used for this research?

A.) inducing crystal formation in substances that do not naturally crystallize B.) producing crystals that contain a smaller number of molecules C.) studying the way other chemicals transition from solid to liquid to gas D.) increasing the time it takes for ice crystals to form on road surfaces -Answer C

In terms of bond strength, which of the following is the weakest?

A.) ionic B.) covalent and hydrogen C.) covalent D.) hydrogen E.) Bonds cannot be strong or weak. -Answer D

A cell is unable to take up or make sugars. Which molecules will it be unable to take up or make?

A.) lipids and proteins B.) carbohydrates and nucleic acids C.) carbohydrates and lipids D.) nucleic acids and lipids E.) proteins and nucleic acids -Answer B

The ability to _____ is not a generally recognized characteristic of most (if not all) living organisms?

A.) maintain homeostasis B.) reproduce C.) sense and respond to the environment D.) grow E.) obtain energy directly from sunlight -Answer E

What are prions?

A.) misfolded proteins that can cause disease and spread by causing normal proteins to misfold as well B.) brain proteins that have been damaged by heat from a high fever and no longer function properly C.) complexes of proteins that contain their own genetic material and can reproduce inside other cells D.) specialized proteins that viruses need in order to invade cells and produce copies of the viruses -Answer A

The cell membrane is made of _______.

A.) phospholipids B.) water C.) nucleotides D.) proteins E.) phospholipids and proteins -Answer E

Identify the smallest subunits of life that can also sometimes be considered living organisms on their own.

A.) proteins B.) DNA molecules C.) cells D.) phospholipids E.) inorganic molecules -Answer C

Which trait is NOT a functional characteristic of all living things?

A.) sense and respond to stimuli B.) acquire and consume energy C.) maintain homeostasis D.) grow and reproduce E.) protect self from predators -Answer E

Coffee or tea with sugar dissolved in it is an example of a water-based solution. Coffee in this case is the __________________, sugar is the _________________, and this means that the sugar molecules must be __________________.

A.) solution; solute; hydrophilic B.) solvent; solute; hydrophilic C.) solute; solvent; hydrophobic D.) solvent; solute; hydrophobic E.) solute; solvent; hydrophilic -Answer B

Which of the characteristics of life does a virus display, even though its characterization as being alive is controversial?

A.) the ability to grow B.) the ability to reproduce C.) the abilities to reproduce, maintain homeostasis, and grow D.) the abilities to reproduce and grow E.) the ability to maintain homeostasis -Answer D

What determines the identity of a particular atom? Select the TWO answers that are correct.

A.) total number of neutrons in orbitals B.) total number of electrons in orbitals C.) number of electrons in the inner most energy shell D.) number of protons and number of neutrons in the nucleus E.) number of protons in the outermost energy shell -Answer B,D