Kinkle Biology Exam 1

Are viruses alive?

Are viruses alive?

Yes and no, they don't have ribosomes which is needed for protein synthesis but they do technically reproduce by by hijacking a hosts cell

What are the defining characteristics of all living organisms?

1. Cellular Organization

2. Ordered Complexity

3. Sensitivity

4. Growth, Development & Reproduction

5. Energy Utilization

6. Homeostasis

7. Evolutionary Adaptation

What is science and how does it work?

• Seeks to explain natural world • Assumes we can trust our senses • Explanations are tested using evidence from the natural world • Tests explanations against observations and rejects ones that fail • Hypotheses must be testable • SCIENCE NEVER PROVES ANYTHING

A dental student wants to test if fluoride is an effective additive against tooth decay. The student studies tooth decay in a population of people who live in neighborhoods supplied with fluoridated water. This student would like to ask whether access to fluoridated water prevent tooth decay. What would be an effective control group to ask this question?

A. Individuals with access to fluoridated water B. Individuals with access to differing amounts of fluoride in the water C. Individuals who have fluoride added to their toothpaste but not their water D. Individuals with access to water with no fluoride added

D. Individuals with access to water with no fluoride added

Science would be most useful for deciding...

A. The best type of music to listen to B. If reproductive cloning should be allowed C. Whether hand washing with soap kills bacteria D. What form of religion to believe in

C. Whether hand washing with soap kills bacteria

Hypotheses that are consistent with the results of experimental testing are...

A. Accepted without further question B. Conditionally accepted C. Modified and reworked until true D. Rejected

B. Conditionally accepted

Which of the following is not a characteristic of all living things?

A. Evolution B. Metabolism C. Locomotion D. Genetic Material E. Reproduction

C. Locomotion

What are the key overarching themes of biology?

1. Life is subject to chemical and physical laws

2. Structure determines function

3. Living systems transform energy and matter

4. Living systems depend on information transactions

5. Evolution explains the unity and diversity of life

What distinguishes living organisms from nonliving matter?

A. Only living organisms are characterized by the processes of metabolism, reproduction and evolution. B. Only living organisms are composed of molecules. C. Living organisms do not obey physical and chemical laws, whereas nonliving matter does. D. Only living organisms increase in size.

A. Only living organisms are characterized by the processes of metabolism, reproduction and evolution.

Which of the following is not a feature of scientific hypotheses?

A. They can be proven true B. They make predictions C. They are typically based on observations D. They can be tested by experimentation

A. They can be proven true

Based on the large numbers of offspring produced by many organisms, Darwin proposed that mortality was high and only a few individuals survived to reproduce. He called the differential reproductive success of individuals with particular variations:

A. evolution B. artificial selection C. natural selection D. inheritance of acquired characteristics

C. natural selection

List the unifying themes of biology

• Cells as a basic unit of life

• Energy transfer and transformation

• Feedback and regulation

• DNA as common genetic material

• Common evolutionary history explains both similarities and diversity

• Structure and function relationships

• Emergent properties

Define evolution

• Decent with modification • Genetic changes in a population over time • Explains the unity and diversity of life

Evolution is a...

Fact

Describe Darwin's theory of evolution by natural selection

• Current organisms are descendants of ancestral species • Species change over time • Descent with modification • Natural selection causes these changes

List the requirements for evolution

1. Variation of traits

2. Heredity

3. Differential Reproduction

4. Time

What are some common misconceptions about evolution?

• Evolution is a theory about the origin of life • Because evolution is slow, humans cannot influence it • Evolution only occurs slowly and gradually • Genetic drift occurs only in small populations

A critical requirement of Darwin's theory is...

A. an uncontrolled growth in all species B. that the earth is relatively young C. all individuals of any given species be identical D. genetic variation is possible in nature E. all species are made at the same time

D. genetic variation is possible in nature

Which of the following is not a misconception that applies to evolution in general and Dr. Lenski's experiments in particular?

A. Individual bacteria cells are evolving B. Species of bacteria that try harder (through metabolic regulation) are able to evolve faster and thus get what they need to survive. C. It has been nearly impossible to observe evolution since it occurred so long ago and is a very slow process, if it occurs at all. D. The populations of bacteria did not evolve by chance, but rather those cells that were able to survive and reproduce better, due to chance mutations, were able to increase in number

D. The populations of bacteria did not evolve by chance, but rather those cells that were able to survive and reproduce better, due to chance mutations, were able to increase in number

Are humans still evolving?

Yes

Which of the following is incorrect?

A. Homo sapiens are humans B. Humans are in the order omnivores C. Humans are still evolving D. Humans are eukaryotes E. Through evolutionary time there have been several different species of humans

B. Humans are in the order omnivores

A key point in Darwin's explanation of evolution is that...

A. the biological structures most likely inherited are those that have become better suited to the environment through constant use. B. slight variations among individuals significantly affect the chance that a given individual will survive in its environment and be able to reproduce C. genes change in order to help organisms cope with problems encountered within their environments. D. extinction is nature's way of weeding out undeserving organisms.

B. slight variations among individuals significantly affect the chance that a given individual will survive in its environment and be able to reproduce.

Darwin proposed that the process of natural selection was the mechanism for...

Evolution

Hypotheses which are consistent with the results of experimental testing are

conditionally accepted

Evolution is...

A. the change in the genetic makeup of an individual through time B. the change in the genetic makeup of a population through time C. only a theory D. not influenced by natural selection

B. the change in the genetic makeup of a population through time

Which is not a misconception about evolution?

A. It only happens slowly over a long period of time B. Individuals can evolve C. It is considered a fact since it has been observed many times D. Evolution is about the origin of life

C. It is considered a fact since it has been observed many times

The nucleus of an atom is composed of...

protons and neutrons

The atomic mass of an element equals...

A. neutrons in an atom B. protons in an atom C. neutrons plus the number of protons D. electrons in an atom

C. neutrons plus the number of protons

The ability of atoms to combine with other atoms is determined by...

A. the atom's atomic weight B. the atom's ability to form isomers C. the number and distribution of electrons D. pH

C. the number and distribution of electrons

Protons are to atomic number as electrons are to...

A. atomic mass B. neutral charge C. positive charge D. chemical behavior

D. chemical behavior

How can isotopes be used in biology and medicine?

Cobalt-60 used as radiation to slow cancer growth

What process is this: 6CO2+6H20-->C6H12O6+6O2

Photosynthesis

Covalent Bond

Sharing of electron pairs

Ionic Bond

Attraction of opposite charges

Hydrogen Bond

Attraction between a slightly positive hydrogen atom and a slightly negative atom.

Hydrophobic Interaction

Interaction of nonpolar substances in the presence of polar substances

van der Waals interaction

Interaction of electrons of nonpolar substances

Where does most of the mass of wood come from?

A. sun B. water C. air D. soil

C. air

Explain the discrete energy levels in which electrons orbit the nucleus of an atom and how this is related to potential energy.

As an electron moves to further from the nucleus to a higher energy level, its potential energy increases.

Relate position in the periodic table to atomic structure and the formation of ions

• Valence electrons determine group number

• Energy level determines the period

• Number of protons determines the element and its position on the PT

How do covalent and ionic bonding both help a reactive atom achieve stability?

Atoms will bond to fill their outer shell, making them more stable

Covalent Bond is between...

Two nonmetals

Ionic Bond is between...

A metal and a nonmetal

Metallic Bond is between...

Two metals

Two carbon atoms might be joined to each other by the sharing of two pairs of electrons, forming a(n)

Double Bond

When one atom loses an electron to another atom, it results in the formation of

A. a polar covalent bond and a new molecule. B. cations and anions that can form ionic bonds. C. a covalent bond between the two. D. many hydrogen bonds.

B. cations and anions that can form ionic bonds

3 factors that influence chemical reactions

1. temperature

2. concentration of reactants and products

3. catalysts

The H and O atoms within a single water molecule have very different electronegativities and therefore form _____ with each other

A. hydrogen bonds. B. polar covalent bonds. C. nonpolar covalent bonds. D. ionic bonds.

B. polar covalent bonds

The slight negative charge at one end of one water molecule is attracted to the slight positive charge of another water molecule. What is this attraction called?

A hydrogen bond

The difference between ions and isotopes...

-ions have lost or gained electrons -isotopes have lost or gained neutrons

How many electrons in a single covalent bond?

2

When the atoms involved in a covalent bond have the same electronegativity, what type of bond results?

nonpolar covalent bond

Which of the following statements about covalent bonds is false?

A. A covalent bond is stronger than a hydrogen bond B. A covalent bond can form between atoms of the same element C. Only a single covalent bond can form between two atoms D. A covalent bond results from the sharing of electrons by two atoms E. A covalent bond can form between atoms of different elements

C. Only a single covalent bond can form between two atoms

What bond involves partial charges between different molecules caused by unequal sharing of electrons?

Hydrogen bond

A polar covalent bond is different from an ionic bond in that a polar covalent bond involves

unequal sharing of electrons

Consider the following electronegativity values: Boron(B)=1.8 Carbon(C)=2.5 Chlorine(Cl)=3.2 Selenium(Se)=2.6

A. B―Cl B. C―Cl C. Se―Cl D. Cl―Cl

D. Cl―Cl

Water has a high specific heat because of the _____.

hydrogen bond formed between the hydrogen of one water molecule and the oxygen of another water molecule

Chemical Reaction

the formation and breaking of chemical bonds, changing the identity of the atoms

Hydrogen bonds are formed

when hydrogen is part of a polar bond

The strongest individual chemical bonds in cells occur when

two atoms share electrons in a covalent bond

Emergent properties of water...

1. High cohesive strength

2. High specific heat

3. Expands when frozen

4. High surface tension

5. Liquid over wide range of temperatures

6. Solvent of life

What does a buffer do?

• minimizes changes in pH

• release H+ when a substance is too basic

• absorb H+ when a substance is too acidic

Cola has a pH of 3 & coffee has a pH of 5. How many times more concentrated is the H+ in cola than in coffee?

100 times

You know that acidosis means that your son's blood pH has...

A. dropped from its normal level and to correct the situation an injection of saline is required to reverse the condition B. raised from its normal level and to correct the situation an injection of saline is required to reverse the condition C. dropped from its normal level and to correct the situation an injection of a buffer is required to reverse the condition D. raised from its normal level and to correct the situation an injection of a buffer is required to reverse the condition

C. dropped from its normal level and to correct the situation an injection of a buffer is required to reverse the condition

The H-bond between two water molecules arises because water is...

Polar

Chemical reactions all involve...

The breaking and formation of chemical bonds

Cholesterol is composed primarily of carbon and hydrogen atoms. Therefore, one would expect cholesterol to be...

A. insoluble in water B. a polar molecule C. an acid D. a buffer

A. insoluble in water

Which of the following statements is false?

A. Distilled water (pH 7.0) has an equal concentration of H+ and OH- ions B. Baking soda (pH 9.0) has a higher concentration of H+ ions than black coffee (pH 5.0) C. Milk of magnesia (pH 10.0) has a higher concentration of OH- ions than seawater (pH 8.0) D. A solution with a lower pH has a higher concentration of H+ ions than a solution with a higher pH E. A solution with a higher pH has a higher concentration of OH- ions than a solution with a lower pH

B. Baking soda (pH 9.0) has a higher concentration of H+ ions than black coffee (pH 5.0)

Water is extremely important in living things for all of the following reasons except...

A. it adheres to substances (wets them) because it is polar. B. it is an excellent buffer. C. it has high specific heat and resists temperature change. D. it is a good solvent; most things dissolve in it. E. it has high heat of vaporization and low density of ice.

B. it is an excellent buffer.

Hydroxyl

carbohydrates, proteins, nucleic acids, lipids

Carbonyl

carbohydrates, nucleic acids

Carboxyl

proteins, lipids

Amino

proteins, nucleic acids

Sulfhydryl

proteins

Phosphate

nucleic acids

Methyl

proteins

Why does ice float in water?

Ice is less dense than water

Which of the following macromolecules are characteristically water-insoluble?

lipids

Three fatty acids bonded together with a glycerol are found in a(n)...

A. alcohol B. enzyme C. phospholipid D. triglyceride

D. triglyceride

Which of the following bonds involves partial charges between different molecules, caused by unequal sharing of electrons within the molecules?

A. Van der Waals bond B. Hydrogen bond C. Ionic bonds D. Polar covalent bonds E. Non-polar covalent bonds

B. Hydrogen bonds

Carbohydrates

1. 3-carbon sugar

2. 5-carbon sugars

3. 6-carbon sugars

CH2O

1. Glyceraldehyde

2. Ribose & deoxyribose

3. Glucose, fructose, galactose

Which of the following contains polymers of glucose?

A. cellulose B. wood C. paper D. amylose E. all of the above

E. all of the above

What aspect of chitin is most likely to give it more strength than cellulose, making it more like a protein?

A. Ionic bonds between adjacent strands of chitin because of the charged O and N atoms. B. Increased hydrogen bonding between strands of chitin because of the greater number of electronegative atoms such as O and N. C. Increased covalent bonding between monomers because of the extra hydrocarbon and double bonds. D. Increased hydrophobic interactions because of the extra hydrocarbon chains.

B. Increased hydrogen bonding between strands of chitin because of the greater number of electronegative

Lipids and their roles...

CH2

• Energy storage (fats and oils)

• Cell membranes (phospholipids)

• Capture of light energy (carotenoids)

• Some hormones and vitamins

• Thermal and electrical insulation

• Water repellency (waxes and oils)

Fats vs. Oils

fats- solid at room temp oils- liquid at room temp

How many water molecules are produced during the formation of a triglyceride from fatty acids and glycerol?

3

What is the linkage between a glycerol and fatty acids of a triglyceride?

Ester linkage

Starch

branched and unbranched, found in plants in the form of starch granules

Glycogen

highly branched and insoluble, found in animal cells, forming glycogen granules

Cellulose

unbranched, very strong and resistant to metabolic breakdown

A fat is most closely related to which of these molecules?

A. a wax B. a phospholipid C. an oil D. cholesterol E. a carotenoid

C. an oil

Which of the following statements concerning electrons is false?

A. Electrons orbit the nucleus of an atom in defined orbitals. B. The outer shell of all atoms must contain eight electrons. C. An atom may have more than one valence shell. D. Electrons are negatively charged particles.

B. The outer shell of all atoms must contain eight electrons.

The monomers making up starch and cellulose are...

glucose

A disaccharide is broken apart into two sugars using a ___________ reaction.

hydrolysis

Which of the following is false about phospholipids?

A. They are partially hydrophilic B. They are partially hydrophobic C. They have a phosphate group attached to a glycerol D. They are a protein

D. They are a protein

Biological membranes contain bilayers of which lipids?

Phospholipids

Which of the following is a property of water?

A. denser in its solid form B. temperature is changed easily C. good at dissolving nonpolar molecules D. water molecules are attracted to each other

D. water molecules are attracted to each other

Which polysaccharide is an important component in the structure of many animals and fungi?

A. chitin B. cellulose C. pectin D. starch

A. chitin

Fats and oils all contain three...

fatty acids

How do phospholipids interact with water molecules?

The polar heads interact with water; the nonpolar tails do not.