Unit 1 Biology Exam ANSWERS

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BIO 106                                 Print Name:   (Last name first)                                                                 

EXAM I, 6/12/2012            

Part I. Multiple Choice.  Choose the one alternative that best completes the statement or answers the question. Answer this section on exam and using clicker.

1) What is biology?

A) the study of life                         B) DNA fingerprinting                     C) the study of genetics 

D) the study of the environment                          E) the study of biomes 

2) The most inclusive level of biological hierarchy listed below that includes all of the organisms and nonliving components of a particular environment.

A) community           B) organism               C) population             D) ecosystem            E) cell 

3) The notion that biological systems are more than the sum of their parts is illustrated by

A) the summation theory.   B) energy flow, processing, and utilization.

C) polymer duality.               D) emergent properties.      E) the complexity/simplicity paradox.

4) Which of the following is not recycled but is lost from ecosystems?

A) carbon      B) nitrogen                C) sodium                   D) energy                  E) magnesium 

5) What are the basic units of life?

A) organelles             B) nuclei                     C) cells           D) DNA molecules    E) A, G, C, and T 

6) Relative to prokaryotic cells, eukaryotic cells are ______.

A) larger and more complex           B) smaller and equally complex      C) smaller and more complex 

D) smaller and simpler                    E) larger and equally complex 

7) Humans are composed of ______ cells.

A) archaeal   B) prokaryotic           C) eubacterial                       D) eukaryotic            E) bacterial

8) Most of the DNA of a eukaryotic cell is found within the ______.

A) ecosystem            B) biome         C) lysosome               D) nucleus                  E) cell membrane

9) Which of the following is a scientific conclusion based on knowing that humans and bacteria share a common genetic language?

A) Humans and bacteria have the same number of genes.

B) The same genetic code was created for humans as for bacteria.

C) Bacteria will eventually develop into humans.

D) The cells of both humans and bacteria store their DNA in a nucleus.

E) Humans and bacteria share a common ancestor.

10) Taxonomy is the ______.

A) study of cells      B) study of genetics                        D) study of natural selection

C) study of organisms and their interaction with the environment

E) naming and classifying of species

11) Which domain(s) consist(s) of prokaryotic cells?  

A) Eukarya only                    B) Archaea and Eukarya                 C) Archaea only

D) Bacteria only                   E) Bacteria and Archaea

12) Which of the following groups of organisms have cells that utilize deoxyribonucleic acid (DNA) as their genetic material but do not have their DNA encased within a nuclear envelope?

A) animal        B) plant          C) archaea     D) fungi          E) protists

13) Based on the interpretation of a graph, which of the following organisms discussed in a Mastering Biology assignment responds to a potential mate depending on the environmental temperature?

A) spiders                  B) Zonosemata flies             C) crickets     D) bullfrogs               E) houseflies

14) Which of the following elements is NOT one of the four most common elements in living systems?

A) zinc           B) nitrogen                C) carbon                   D) hydrogen              E) oxygen

15) An atom with a positive charge has ______.

A) more neutrons than protons     B) equal numbers of protons, electrons, and neutrons

C) more electrons than protons     D) more protons than electrons

E) more protons than neutrons

16) All atoms of an element have the same number of ______.

A) electrons                                      B) neutrons                C) protons plus neutrons

D) electrons plus neutrons              E) protons

17) An atom's protons are found in its ______.

A) molecule               B) neutron                 C) shell           D) orbital       E) nucleus

18) Beryllium's atomic mass is 9 and its atomic number is 4. How many neutrons are found in a beryllium atom?

A) 9                B) 5                 C) 4                 D) 2                E) 13

19) Isotopes of an element have the same number of ______ and different numbers of ______.  

A) protons . . . neutrons      B) protons . . . electrons     C) neutrons . . . electrons

D) electrons . . . protons     E) neutrons . . . protons

20) The second electron shell of an atom can hold a maximum of ______ electron(s).

A) 2                B) 3                 C) 6                             D) 8                E) 1

21) An atom with an electrical charge is a(n) ______.

A) isotope      B) compound              C) radioisotope                     D) molecule               E) ion

22) The bond between oppositely charged ions is a(n) ______ bond.  

A) covalent                B) polar covalent                  C) isotonic                 D) ionic          E) hydrogen

23) What name is given to bonds that involve the sharing of electrons?

A) ionic          B) isotonic     C) van der Waals      D) covalent                E) hydrogen

24) Adjacent water molecules are joined by ______ bonds.

A) polar and covalent          B) trivalent                C) hydrogen   D) covalent only        E) ionic

25) Why is water considered a polar molecule?  

A) It remains liquid even at very low temperatures.

B) The oxygen is found between the two hydrogens.

C) Both hydrogens are at one end of the molecule, and oxygen is at the other end.

D) The negatively charged oxygen atom attracts the positively charged hydrogen atoms.

E) Its electrons spend more time with its oxygen than with either hydrogen.

26) Why (if you are careful) are you able to float a needle on the surface of water?

A) A single needle is less dense than water.

B) The surface tension that is a result of water's cohesive properties makes this possible.

C) The polarity of individual water molecules makes this happen.

D) Water exhibits adhesive properties.

E) The covalent bonds that hold a water molecule together are responsible for this ability.

27) The lower the pH of a solution, the ______.

A) less toxic the solution                B) more basic the solution C) more acidic the solution

D) greater the number of oxygen atoms                         E) higher the OH— concentration

28) What name is given to substances that resist changes in pH?

A) sugar                     B) acids                      C) bases                     D) buffers                 E) salt

29) Which drawing depicts the electron configuration of carbon (atomic number = 6)?

30) The tendency of water molecules to stick together is referred to as ______.

A) adhesion               B) polarity                 C) transpiration        D) evaporation          E) cohesion

31) Water's surface tension and heat storage capacity are accounted for by its ______.

A) hydrogen bonds   B) size            C) weight                   D) mass                      E) orbitals

32) In a water molecule, hydrogen and oxygen are held together by a(an) ______ bond.

A) ionic          B) double covalent    C) nonpolar covalent            D) hydrogen              E) polar covalent

33) A hydrogen atom has 1 electron. How many covalent bonds can hydrogen form?  

A) 2                B) 1                 C) 5                 D) 4                E) 3

34) The following molecule is best described as a ______. CH3—CH2—CH2—CH2

A) protein      B) nucleic acid          C) carbohydrate                   D) lipid           E) hydrocarbon

35) Which of the following statements is true about buffer solutions?

A) They maintain a relatively constant pH when either acids or bases are added to them.

B) They maintain a constant pH when acids are added to them but not when bases are added to them.

C) They maintain a constant pH when bases are added to them but not when acids are added to them.

D) They are found only in living systems and biological fluids.

E) They maintain a constant pH of exactly 7 in all living cells and biological fluids.

36) Carbohydrates typically have ______.

A) a PO4 group         B) C, H, and O in a 1:2:1 ratio        C) a hydrocarbon chain

D) a 5-carbon ring   E) an NH2 group

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

A) different side chains (R groups) attached to an alpha (α) carbon

B) different amino groups attached to an alpha (α) carbon

C) different asymmetric carbons

D) different alpha (α) carbons

E) different carboxyl groups attached to an alpha (α) carbon

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

A) carbohydrates                 B) lipids                      C) proteins                             D) nucleic acids

39) Complete the equation: monosaccharide + monosaccharide → ______ + water

A) fat                         B) disaccharide         C) polysaccharide     D) nucleic acid          E) polypeptide

40) Which of the following is an example of a polysaccharide?

A) fructose               B) glucose      C) starch                   D) maltose                 E) sucrose

41) Why are hydrocarbons insoluble in water?

A) They are lighter than water.

B) The majority of their bonds are polar covalent carbon-to-hydrogen linkages.

C) The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages.

D) They are hydrophilic.

E) They exhibit considerable molecular complexity and diversity.

42) Animals store carbohydrates as ______.

A) starch                   B) glycogen                C) cellulose                D) glucose      E) maltose

43) Cellulose is an example of ______. 

A) a nucleic acid       B) a polypeptide        C) fat                         D) a steroid               E) fiber

44) Examine the two sugars in the following figure. How do these two sugars compare?

A) Glucose has more double bonds.                       B) Fructose has more hydrogen.

C) Glucose has more hydrogen.                  D) They are structurally identical in every way.

E) Glucose and fructose are isomers.

45) Sometimes when I have my morning coffee, which I drink black with no sugar, I notice a thin film floating on top of the coffee. Since I have just read Chapter 3 of the text, I now realize the nature of this substance and so I run to my friends screaming, "Look at this ______ in my coffee!"

A) enzyme                             B) hydrophilic substance                 C) hydrocarbon        

D) hydrophobic substance E) nucleotide

46) Saturated fats are saturated with ______.

A) nitrogen                B) phosphorus           C) hydrogen               D) oxygen                  E) carbon

47) By definition, what type of fatty acid has double bonds and is likely to be liquid at room temperature?

A) saturated                         B) monoglyceride      C) triglyceride          D) unsaturated         E) steroid

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

A) They are both polymers of glucose.                B) They are cis-trans isomers of each other.

C) They can both be digested by humans.           D) They are both used for energy storage in plants.

E) They are both structural components of the plant cell wall.

49) The function of a biological molecule is most dependent on its ______.

A) size            B) pH              C) temperature         D) shape        E) weight

50) The linear sequence of monomers in a polypeptide chain is referred to as its ______ structure.

A) primary     B) quaternary            C) tertiary     D) pentamerous        E) secondary

51) Nucleic acids are polymers of ______ monomers.

A) hydrocarbon        B) nucleotide                         C) fatty acid                         D) DNA          E) monosaccharide

52) Which of the following store and transmit hereditary information?

A) proteins         B) carbohydrates                 C) lipids                          D) nucleic acids

53) The primary structure of a protein is ______.

A) an α helix or a pleated sheet                B) the amino acid sequence of the polypeptide chain

C) irregular folding                                      D) composed of two or more polypeptide chains

E) maintained by hydrogen bonds

54) Which of these is a difference between DNA and RNA?

A) In DNA, adenine pairs with guanine; in RNA, adenine pairs with thymine.

B) RNA is double-stranded; DNA is single-stranded.

C) DNA consists of five different nucleotides; RNA consists of four different nucleotides.

D) DNA contains thymine; RNA contains uracil.

E) DNA is found in the nucleus; RNA is never found in the nucleus.

55) A controlled experiment is one in which

A) the experiment is repeated many times to ensure that the results are accurate.

B) there are at least two groups, one of which does not receive the experimental treatment.

C) there are at least two groups, one differing from the other by two or more variables.

D) there is one group for which the scientist controls all variables.

E) the experiment proceeds at a slow pace to guarantee that the scientist can carefully observe all reactions and process all experimental data.

56) Why is it important that an experiment include a control group?

A) A control group is required for the development of an "If…then" statement.

B) The control group provides a reserve of experimental subjects.

C) The control group is the group that the researcher is in control of, the group in which the researcher predetermines the results.

D) Without a control group, there is no basis for knowing if a particular result is due to the variable being tested.

E) A control group assures that an experiment will be repeatable.

57) If one strand of a DNA molecule has the sequence of bases 5'ATTGCA3', the other complementary strand would have the sequence

A) 5'UGCAAU3'.       B) 3'TAACGT5'.      C) 3'UAACGU5'.     D) 5'UAACGU3'.       E) 5'TAACGA3'.

58) Polysaccharides, triacylglycerides, and proteins are similar in that they

A) are synthesized as a result of peptide bond formation between monomers.

B) are decomposed into their subunits by dehydration reactions.

C) are synthesized from monomers by the process of hydrolysis.

D) are synthesized from subunits by dehydration reactions.

E) all contain nitrogen in their monomer building blocks.

59) Which level of protein structure do the α helix and the β pleated sheet represent?

A) primary     B) secondary             C) tertiary                 D) quaternary           E) none of the above

60) 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 in a polypeptide chain.

C) unique three-dimensional shape of the fully folded polypeptide.

D) organization of a polypeptide chain into an α helix or β pleated sheet.

E) overall protein structure resulting from the aggregation of two or more polypeptide subunits.

Part II. Short Answer

61) (5 pts.) How many water molecules are shown in the drawing below?      5         

a. Circle and label one example of a polar covalent bond in the image below

b. Circle and label one example of a hydrogen bond in the image below

c. Which bond is stronger the polar covalent bond or the hydrogen bond (circle one)

62) (6 pts.) KCl will dissociate into K⁺ and Cl ^– ions when dissolved in water. Which ion (A or B) represents the K⁺ ion and which one the Cl^-  ion? Explain how you can tell

The K⁺ is going to be attracted to the delta negative charge of oxygen. Therefore “A” is K⁺.
The Cl^- is going to be attracted to the delta positive charge of hydrogen. Therefore “B” is Cl^-.

63)(3 pts.) Briefly describe the role temperature had on the dependent variable in the experiment sited in question 13. 

The temperature caused crickets to change their chirping habbits, which affected the response of female crickets to the chirping noise.

64. (6 pts.) Name each of the following functional groups found in this tripeptide. (Spelling must be close for full credit.)

 

A.Phosphate

B.Sulfhydrol

C.Amino

D.Carbonyl

E.Hydroxyl

F.Carboxyl

65) (12 pts.) Complete the table using the terms provided:  amino acids, ester linkages,  glycosidic linkages,  lipids, monosaccharides, nucleic acids, nucleotides,  peptide bonds, polynucleotides, polysaccharides, proteins, triacylglycerol

Major  Class of macromolecule	Monomers or components	Polymer or larger molecule	Type of linkage
Lipids	Fatty acids & glycerol	triacylglycerol	Ester linkages
Proteins	Amino Acids	Polypeptide	Peptide bonds
Carbohydrates	Monosaccharides	polysaccharides	Glycosidic linkages
Nucleic Acids	Nucleotides	polynucleotides	Phosphodiester linkage

66) (4 pts.) What is meant by the unity in the diversity of life? Give one specific example.

  - Life’s Unity can be described in both The definition of life and in the seven themes of life. All life is similar in that it uses energy, interacts with its environment, it’s smallest unit is a cell, uses DNA, all cells are encased in a plasma membrane and all cells have some kind of DNA (just to name a few ways that all life is unified). The diversity of life speaks to how all life is different. We start by noticing the differences when looking at classification systems. All differences are noted in the different names of each species. A few differences to note are differences in size, metabolism, structure, life-span, and trophic levels, just to name a few.

67) (4 pts.) Can a scientific hypothesis ever be proven? Briefly explain your answer.

 

Science can only either support or fail to support a null hypothesis or a hypothesis.  Because of uncertainty in many areas such as our five senses, the nature of the true physical world and in epistemology, we can never be 100% certain of anything until we perform that function 100% of the possible times, which can never be obtained for a repeatable experiment.  Therefore we can only come to a degree of certainty. This precludes a scientist from ever “proving” anything.