General Biology 1 Exam 1

A scientist conducts a procedure that causes nitrogen atoms to gain neutrons. The resulting atoms will be: A) ions of nitrogen. B) positively charged. C) negatively charged. D) isotopes of nitrogen. E) new elements with higher atomic numbers.

D) isotopes of nitrogen.

Atomic nuclei contain protons and ________. A) isomers B) ions C) moles D) neutrons

D) neutrons

The area around a nucleus where an electron is most likely to be found is the: A) electrical space. B) energy level. C) polar space. D) orbital.

D) orbital.

Sugars dissolve well in water because of water's ________. A) ionic bonds B) cohesiveness C) hydrophobic exclusion D) polarity

D) polarity

Mendeleev found that when he arranged the known elements according to their atomic mass, the entries in the table exhibited a pattern of chemical properties that repeated itself in groups of eight elements. This led to the generalization now known as: A) an atomic model. B) valance electrons. C) the periodic table. D) the octet rule.

D) the octet rule.

When water ionizes, it produces equal amounts of hydrogen and hydroxide ions that can reassociate with each other. The pH of water is: A) 3 B) 4 C) 5 D) 6 E) 7

E) 7

Cell theory is one of the foundations of biology. What are the tenets of the cell theory? Check all that apply. A) All organisms are made up of more than one cell. B) All cells have the ability to move. C) Cells carry genetic material passed to daughter cells during cellular division. D) Cells arise from other cells through the process of cell division. E) Organisms are formed through spontaneous generation F) All living organisms consist of cells

E) Organisms are formed through spontaneous generation

Differences in domesticated animals over relatively short periods of time most likely occur through: A) natural selection B) adaptation C) evolution D) experimental selection E) artificial selection

E) artificial selection

In a chemical analysis of an animal tissue sample, which element would be in the least quantity? A) carbon B) hydrogen C) nitrogen D) oxygen E) iodine

E) iodine

Atoms of a single element that possess different numbers of neutrons are called: A) polymers. B) ions. C) monomers. D) isomers. E) isotopes.

E) isotopes.

Because oxygen is more electronegative than hydrogen, the water molecule is: A) hydrophobic. B) hydrophilic. C) nonpolar. D) ionic. E) polar.

E) polar.

What is electronegativity? How does it affect interactions between water molecules?

Electronegativity is an atom's attraction for the electrons in a covalent bond. It affects interactions between water molecules because water consists of oxygen and hydrogen, but oxygen is more electronegative than hydrogen. Shared electrons are more likely to gravitate towards hydrogen.

What would be the effect on the properties of the water molecule if oxygen and hydrogen had equal electronegativity?

If oxygen and hydrogen had equal electronegativity, then the shared electrons would be pulled equally close to both atoms creating a non polar covalent bond rather than a polar covalent bond. There would be an equal distribution of charges, so water would no longer be a polar molecule.

What is pH? What is the difference between acid and base?

pH is a measure of how acidic/basic water is. An acid is any substance that increases the H+ concentration of a solution. A base is any substance that reduces the H+ concentration of a solution.

Chapter 2

Nature of Molecules and Properties of Water

Chapter 1

The Science of Biology

What is the difference between atomic number and mass number?

The atomic number is the number of protons in its nucleus. The mass number is the number of protons plus neutrons in the nucleus.

Is water a polar or non-polar solvent? Justify

Water is a polar solvent because oxygen (O) is more electronegative than hydrogen (H), shared electron are pulled more toward oxygen.

Water is a universal solvent. Explain it.

Water is a universal solvent because water can also dissolve compounds made of nonionic polar molecules. Even large polar molecules such as proteins can dissolve in water if they have ionic and polar regions.

Water is life. Briefly explain it.

Water is the biological medium on Earth. Three-quarters of Earth's surface is covered by water. Water is the only common substance to exist in the natural environment in all three physical states of matter. Water's unique emergent properties help make Earth suitable for life. The structure of the water molecule allows it to interact with other molecules.

What are the major properties of water? Explain one them.

- The major properties of water are universal solvent, cohesion and adhesion, high surface tension, high heat capacity, and changes in density (expansion upon freezing). - Water is a universal solvent because water can also dissolve compounds made of nonionic polar molecules. Even large polar molecules such as proteins can dissolve in water if they have ionic and polar regions. - Water has properties of cohesion and adhesion because hydrogen bonds hold water molecules together, a phenomenon called cohesion. Adhesion is an attraction between different substances, for example, between water and plant cell walls. - Water has an unusually high surface tension due to hydrogen bonding between the molecules at the air-water interface and to the water below. - Water absorbs heat from warmer air and releases stored heat to cooler air. Water can absorb or release a large amount of heat with only a slight change in its own temperature.

Recent discoveries of microscopic fossils have extended the known history of life to about: A) 3.5 billion years ago. B) 2 billion years ago. C) 4.5 billion years ago. D) 1 billion years ago.

A) 3.5 billion years ago

Consider the following electronegativity values: Boron (B) = 1.8 Carbon (C) = 2.5 Chlorine (Cl) = 3.2 Selenium (Se) = 2.6 Which of the following bonds is the most polar? A) B-Cl B) C-Cl C) Se-Cl D) It cannot be determined from the information provided.

A) B-Cl

What common life characteristic would cells from a daisy, bacteria, and a dog all have? A) DNA B) cell walls C) organs D) ability to conduct photosynthesis

A) DNA

Plants transport water to their leaves through the xylem when water evaporates from the leaves. The evaporating water pulls other water molecules up the xylem through ________. A) Hydrogen bonds B) Ionic bonds C) Covalent bonds D) Hydrophobic interactions

A) Hydrogen bonds

Salt is often used to melt ice on roads during the winter because it lowers the freezing/melting point of water. When salt dissolves in water, individual Na+ and Cl- ions break away from the salt lattice and become surrounded by water molecules. Why would this cause ice to melt? A) Hydrogen bonds are broken, and the salt ions interfere with interactions between H and O. As a result, it is more difficult for water molecules to bond and form ice. B) Hydrogen bonds are formed, and the salt ions bond with O. As a result, it is more difficult for water molecules to bond and form ice. C) Hydrogen bonds are broken, and the salt ions bond with O and H respectively. As a result, it is more difficult for water molecules to bond and form ice.

A) Hydrogen bonds are broken, and the salt ions interfere with interactions between H and O. As a result, it is more difficult for water molecules to bond and form ice.

Sue was monitoring the oil spill into the Gulf of Mexico from an oil tanker. From her observations, she noted that the oil was moving as large patches in the water. It did not appear as though the oil was dissolving into the water. Why did the oil not dissolve into the water? A) Hydrophobic interactions B) Surface tension C) Sea water acts as a solvent D) Water forms hydration shells E) Water has a high heat of vaporization

A) Hydrophobic interactions

You recently discovered a new element, and find that this particular element has one electron in its outer energy level. What would you expect will happen to an atom of this element if placed in water? A) It will lose an electron forming a positive ion. B) It will lose an electron forming a negative ion. C) It will gain an electron forming a positive ion. D) It will gain an electron forming a negative ion.

A) It will lose an electron forming a positive ion.

As you and a friend are entering a chemistry laboratory at your university, you see a sign that states: DANGER—RADIOACTIVE ISOTOPES IN USE. Your friend is an accounting major and has not had any science courses yet. She asks you what a radioactive isotope is and you respond correctly with: A) Radioactive isotopes are atoms that are unstable and as a result emit energy in a process called radioactive decay. B) Radioactive isotopes are atoms that are stable and as a result emit energy in a process called radioactive decay. C) Radioactive isotopes are atoms that are stable and as a result only emit energy if they are exposed to higher temperatures. D) Radioactive isotopes are atoms that are unstable but unless actively disturbed by some chemical process will remain intact and pose no problems.

A) Radioactive isotopes are atoms that are unstable and as a result emit energy in a process called radioactive decay.

You walk down into your basement to find that the carpeting on the floor is damp. Concerned, you look around for large puddles of water or broken pipes, but find none. In fact, only the basement floor and carpeting is damp. You realize that water must have wicked into the carpet from the floor by ________. A) adhesion and cohesion B) adhesion and solubility 11 C) adhesion, cohesion, and solubility D) cohesion and solubility

A) adhesion and cohesion

You explain to your study group that a hypothesis is: A) an explanation that accounts for careful observations. B) a proposition that will be true and fits the known facts. C) a theory D) constant over time.

A) an explanation that accounts for careful observations.

The number of protons in a given atom is equal to its: A) atomic number B) mass C) neutron number D) molecular number

A) atomic number

Matter is composed of: A) atoms B) energy C) mass D) molecules

A) atoms

Bicarbonate ions in the blood can absorb hydrogen ions, keeping pH balanced. Bicarbonate is acting as a ________ in blood. A) buffer B) acid C) base D) alkaline

A) buffer

The smallest subatomic particle is the ________. A) electron B) ion C) isotope D) neutron E) proton

A) electron

Negatively charged subatomic particles that have almost no mass are called: A) electrons. B) protons. C) neutrons. D) ions. E) polymers.

A) electrons.

The proposal that one type of organism can change gradually into another type over a long period of time is known as: A) evolution. B) natural history. C) preconception. D) preservation.

A) evolution

Nitrogen has a higher electronegativity than hydrogen. As a result you would expect that ammonia (NH3) molecules can form ________ with each other. A) hydrogen bonds B) hydrophilic bonds C) ionic bonds D) covalent bonds E) cohesive bonds

A) hydrogen bonds

The amino acid glycine (C3NO2H6) is a(an): A) organic molecule B) inorganic molecule C) element D) vitamin

A) organic molecule

The negative logarithm of the hydrogen ion concentration in the solution is referred to as: A) pH B) atomic mass C) -OH concentration D) electronegativity E) specific heat

A) pH

The atomic number of an element is equal to the number of: A) protons only. B) neutrons only. C) protons plus electrons. D) protons plus neutrons. E) neutrons plus electrons.

A) protons only.

All atoms tend to fill their outer energy levels with the maximum number of electrons, usually eight. Depending on whether atoms satisfy the octet rule will predict: A) the chemical behavior of the atoms. B) whether they will be found in nature. C) whether they will dissolve in water. D) their radioactive energy.

A) the chemical behavior of the atoms.

The two nitrogen atoms in nitrogen gas (N2) share six electrons forming a ________. A) triple covalent bond B) double covalent bond C) single covalent bond D) hydrogen bond E) double bond

A) triple covalent bond

Elements are essential to life. Briefly explain it

About 20-25% of the 92 elements are essential to life (essential elements) Carbon, Hydrogen, Oxygen, and Nitrogen make up 96% of living matter Most of the remaining 4% consists of Calcium, Phosphorus, Potassium, and Sulfur Trace elements (example: iodine, manganese etc.) are those required by an organism in only minute quantities

What does water do for animal life?

Animals need fresh water for their bodies to function. They gain water not only through the action of drinking but also from the food they eat. Water is vital for bodily functions such as regulation of temperature, nutrient uptake, removing wastes, body weight, and health.

One mole of a substance contains 6.02 x 10^23 molecules. The atomic number of Li is 3 and the atomic mass is approximately 7. If you have three moles of Li, how many grams does it weigh? A) 9 B) 21 C) 7 x 6.02 x 10^23 D) 3 x 6.02 x 10^23

B) 21

A chemist adds a chemical to pure water and there is a 100-fold increase in the concentration of hydrogen ions. What is the best approximation of the new pH value? A) 0 B) 5 C) 7 D) 9 E) 14

B) 5

Oxygen has an atomic mass of 16 and an atomic number of 8. How many neutrons are present? A) 24 B) 8 C) 16 D) 4

B) 8

The pH of your small intestines is around 7.5 and the pH of your large intestine can be 5.5. As substances travel from the small intestines to the large intestine, what would happen to the H+ ion concentration? A) It decreases 100-fold. B) It increases by 100-fold. C) It increases 10-fold. D) It increases 2-fold. E) It decreases 10-fold.

B) It increases by 100-fold.

Why is it necessary to take special safety precautions when using radioactivity? A) Radioactive substances will ionize cells. B) Radioactive substances have the potential to cause damage to living cells. C) Radioactive substances decay. D) Radioactive substances will perforate plasma membranes.

B) Radioactive substances have the potential to cause damage to living cells.

Why is it necessary to take an interdisciplinary approach to studying biology? A) Interdisciplinary approaches are required to answer all scientific questions since all disciplines borrow knowledge from each. B) Research methods used to solve many biological questions often require a number of different types of approaches and the expertise of a variety of scientists. C) An interdisciplinary approach is the only way we can further our biological knowledge

B) Research methods used to solve many biological questions often require a number of different types of approaches and the expertise of a variety of scientists.

Water is most dense and thus heaviest at 4°C. At 0°C, ice forms and can float on liquid water. Suppose ice were most dense at 0°C. What would happen in a lake at this temperature? A) The ice would cover the surface of the aquatic system and would never melt. B) The ice would cover the bottom of the aquatic system and would build up in layers over time. C) Ice would not form because solids are always less dense than liquids. D) The cold temperatures and the subsequent ice formation would prevent hydrogen bonds from forming between the water molecules, thus causing the existing ice crystals to become disassociated from each other.

B) The ice would cover the bottom of the aquatic system and would build up in layers over time.

A key contribution to Darwin's thinking was the concept of limits put on the geometric growth of populations by nature, originally proposed by: A) Charles Lyell. B) Thomas Malthus. C) Karl Popper. D) Peter Raven. E) Russel Wallace.

B) Thomas Malthus.

Structures that have similar structure and function but different evolutionary origins are called: A) homologous. B) analogous. C) inherited. D) uniform. E) evolutionary modifications.

B) analogous.

Organisms are composed of molecules, which are collections of smaller units, termed: A) monomers. B) atoms. C) electrons. D) polymers. E) ions.

B) atoms.

When two atoms share a pair of electrons, the bonding is referred to as: A) ionic. B) covalent. C) unstable. D) hydrogen.

B) covalent.

Atoms containing a specific number of protons are called: A) minerals B) elements C) metals D) molecules

B) elements

All atoms possess the ability to do work. The term that is defined as the ability to do work is: A) matter B) energy C) molecules D) space

B) energy

After Darwin concluded his voyage on the Beagle, he proposed that the process of natural selection was a mechanism for: A) artificial selection. B) evolution. C) sexual selection. D) speciation. E) overpopulation of finches on the Galapagos Islands.

B) evolution

The rate at which evolution is occurring cannot be estimated by: A) studying comparative anatomy. B) inferring that apes are related to humans. C) measuring the degree of difference in genetic coding. D) interpretation of the fossil record.

B) inferring that apes are related to humans.

An atom that is negatively charged because it has accepted an electron is a(n): A) isomer. B) ion. C) isotope. D) monomer.

B) ion.

Atoms in which the number of electrons does not equal the number of protons are known as: A) valences. B) ions. C) isotopes. D) isomers.

B) ions.

When atoms gain or lose electrons, they become negatively or positively charged. These negatively or positively charged atoms are known as A) isotopes. B) ions. C) isomers. D) unstable atoms.

B) ions.

Carbon-12, Carbon-13 and Carbon-14 are examples of: A) ions B) isotopes C) isomers D) molecules

B) isotopes

The reaction (H2 + F2 → 2HF) is an example of a redox reaction. In reality, two half reactions are occurring. The half reaction (H2 → 2H+ + 2e-) is a(n): A) reduction reaction B) oxidation reaction C) redox reaction D) potential energy reaction

B) oxidation reaction

Oxygen-16 is abundant and has 8 protons and 8 neutrons. Oxygen-18 has two extra neutrons. These two forms are: A) oxygen ions. B) oxygen isotopes. C) oxygen isomers. D) oxygen dimers.

B) oxygen isotopes.

Cl + e- → Cl- is an example of a: A) oxidation. B) reduction. C) polymerization. D) ionization.

B) reduction.

An atom has 20 electrons and 20 neutrons. What is the mass of this atom? A) 10 B) 20 C) 40 D) 80

C) 40

Your dog becomes ill and you rush him to the veterinarian's office. A technician draws blood from your dog's leg for a vet-ordered lab test. After a few minutes the lab results are given to the vet, who immediately grabs a bottle from a shelf and begins to fill a syringe with an unknown fluid. You inquire about the fluid, and the vet informs you that the fluid is necessary to manage your dog's metabolic acidosis. Based on the information provided, what is acidosis, and what is the likely effect of the veterinarian's injection? A) Acidosis means that your dog's blood pH has dropped from its normal level, and an injection of saline is required to reverse the condition. B) Acidosis means that your dog's blood pH has increased from its normal level, and an injection of saline is required to reverse the condition. C) Acidosis means that your dog's blood pH has decreased from its normal level, and an injection of buffering solution is required to reverse the condition. D) Acidosis means that your dog's blood pH has increased from its normal level, and an injection of buffering solution is required to reverse the condition

C) Acidosis means that your dog's blood pH has decreased from its normal level, and an injection of buffering solution is required to reverse the condition.

To increase the rate of a reaction you could: A) Add more products. B) Decrease the temperature. C) Add more reactants. D) remove a catalyst

C) Add more reactants.

Science is subdivided into specific areas of study termed disciplines. These divisions are artificial but are helpful to narrow the massive scope of scientific knowledge to a manageable amount. Given what you know about each, which scientific division is likely to present the best answer to a question about how fluid dynamics affect blood pressure in mammals? A) Biochemistry - study of chemical reactions needed for life function, usually at the cellular level. B) Bioinformatics - use of technology to study and store biological data C) Biophysics - study of biological processes through physics D) Biology - study of life

C) Biophysics - study of biological processes through physics

Darwin's theory of evolution is supported by many modern pieces of evidence. Check all that apply. A) New measurements of the age of the term-24earth. B) An understanding of the mechanism of heredity. C) Human population growth. D) Comparative studies of animal structures. E) Similarities in DNA of related species.

C) Human population growth.

Darwin's book in which he described his views on evolution is: A) Principles of Geology. B) On the Principle of Population. C) On the Origin of Species. D) Survival of the Fittest.

C) On the Origin of Species.

Besides Darwin, the theory of evolution by means of natural selection was also independently proposed by: A) Alfred Wallace. B) Charles Lyell. C) Thomas Malthus. D) Karl Popper. E) Peter Raven.

C) Thomas Malthus.

A scientific theory is: A) a suggested explanation that accounts for observations. B) a way to organize how we think about a problem. C) a concept that is supported by experimental evidence that explains the facts in an area of study. D) a way to understand a complex system by reducing it to its working parts.

C) a concept that is supported by experimental evidence that explains the facts in an area of study.

Which element's isotope is commonly used to determine when biological samples such as fossils, were formed? A) oxygen B) hydrogen C) carbon D) nitrogen E) sulfur

C) carbon

Experiments are carried out to test a hypothesis by changing one variable at a time and including an unchanged variable termed a(n) ________. A) experimental variable B) altered variable C) control D) stable variable

C) control

The same basic array of bones is modified to give rise to the wing of a bat and the fin of a porpoise. Such anatomical structures are called: A) analogous. B) uniform. C) homologous. D) inherited. E) evolutionary modifications.

C) homologous.

Water molecules are polar with ends that exhibit partial positive and negative charges. These opposite charges allow water molecules to attract each other through: A) ionic bonds. B) covalent bonds. C) hydrogen bonds. D) peptide bonds.

C) hydrogen bonds.

A suggested explanation that might be true and is subject to testing by further observations is a(n): A) experiment. B) generality. C) hypothesis. D) scientific principle. E) theory.

C) hypothesis

The high heat of vaporization of water helps you to feel cooler when you sweat because the transition of water from a liquid to a gas requires a ________ of energy to break hydrogen bonds. The energy is ________ from heat produced by your body, thus helping to lower the surface temperature of your body. A) release; released B) release; obtained C) input; obtained D) input; released

C) input; obtained

In the crystal matrix of ordinary salt, the sodium and chlorine are held together by: A) peptide bonds. B) covalent bonds. C) ionic bonds. D) hydrogen bonds. E) nonpolar bonds.

C) ionic bonds.

The term that Darwin used to describe the concept that those with superior physical, behavior or other attributes are more likely to survive than those that are not so well endowed, and thus are more likely to pass their traits to the next generation, is called: A) biological diversity B) geometric progression C) natural selection D) superior beings E) survival of modifications

C) natural selection

Which atomic particle has no charge and is located in the nucleus? A) electron B) ion C) neutron D) proton E) isotope

C) neutron

Isotopes that are unstable and decay when their nucleus breaks up into elements with lower atomic numbers, emitting significant amounts of energy in the process, are called: A) energetic B) ionic C) radioactive D) isometric

C) radioactive

Life is thought to have evolved from complex molecules formed by the interaction of smaller molecules in oceans and the atmosphere. The substance which brought these molecules together to interact is A) hydrogen. B) acids. C) water. D) buffers. E) salts.

C) water.

What is the difference between covalent bonds and ionic bonds?

Covalent bonds is when atoms share electrons. Ionic bonds is when atoms transfer electrons.

Sodium has 11 electrons arranged in three energy levels. In order to become stable, sodium forms an ion with: A) no charge. B) -1 charge. C) -8 charge. D) +1 charge. E) +8 charge.

D) +1 charge.

Regardless of its shape, a given orbital may contain no more than: A) 1 electron. B) 4 electrons. C) 8 electrons. D) 2 electrons.

D) 2 electrons.

How many hydrogen bonds can a water molecule form? A) 1 B) 2 C) 3 D) 4 E) 5

D) 4

Based on hierarchical levels of biological organization, which of these choices represents the broadest level? A) Endocrine system B) 3 toed sloths C) School of piranhas D) Amazon Basin E) Jaguars, giant anteaters, macaws, capybaras

D) Amazon Basin

Darwin's ideas on evolution were advanced for his time. His approach to science and natural selection were supported by what main tenet? A) Various organisms and their structures resulted from a spontaneous action. B) Species were unchangeable over the course of time. C) The world is fixed and constant. D) Operation of natural laws produces constant change and improvement.

D) Operation of natural laws produces constant change and improvement.

The sub-atomic particle with a positive charge is ________. A) an electron B) an ion C) a neutron D) a proton E) an isotope

D) a proton

Wings of birds and butterflies have similar functions, but different evolutionary origins. They are: A) homologous structures. B) physiological structures. C) phylogenetic structures. D) analogous structures.

D) analogous structures.

After taking your biology exam, you return to your car only to find that you had left the lights on and now the car battery is dead. Your friend offers to jump-start your car, but when you go to hook up the jumper cables you find that the battery terminals are covered with corrosion due to battery acid condensation. Based off your knowledge, what substance could be used to clean the corrosion? A) coffee (pH of 5) B) water (pH of 7) C) vinegar (pH of 3) D) baking soda (pH of 9)

D) baking soda (pH of 9)

Two oxygen atoms joined to each other by the sharing of two pairs of electrons form a(n): A) single bond. B) ionic bond. C) hydrogen bond. D) double covalent bond.

D) double covalent bond.

Capillary action is one of the forces that aids water's upward movement in plants. The narrower the diameter of the tube, the farther the water column will rise. Capillary action is a result of water molecules: A) storing heat and thus moving faster because of heat of vaporization. B) producing sufficient surface tension to overcome the pull of gravity. C) having a strong cohesive force and attaching to the surrounding vessel walls. D) having an adhesive force, which allows them to attach to the vessel walls. E) being associated with hydrophobic molecules, which can result in upward movement.

D) having an adhesive force, which allows them to attach to the vessel walls.

Water molecules are attracted to each other due to the opposite charges created by partial charge separations within the molecules. These attractions are called: A) peptide bonds. B) covalent bonds. C) ionic bonds. D) hydrogen bonds. E) double bonds.

D) hydrogen bonds.

The method of reasoning that uses construction of general principles by careful examination of many specific cases is called: A) deductive reasoning. B) theoretical reasoning. C) hypothetical reasoning. D) inductive reasoning. E) experimental reasoning.

D) inductive reasoning