Name _________________________________                                          Biology 314

                                                                                                                        Exam 1 – 19 Jan 01

 

Multiple Choice (2 points each) – circle the one correct answer.

 

1.      The feature that most clearly separates eukaryotes from prokaryotes is the presence in eukaryotic cells of

 

A.     ribosomes

B.     oxidative phophorylation

C.     DNA molecules

D.    a nucleus

 

2.     The first living cells are thought to have arisen about

 

A.     4.5 billion years ago

B.    3.5 billion years ago

C.     2.5 billion years ago

D.     1.5 billion years ago

 

3.     The initial importance of a membrane enclosing self-replicating RNA molecules and associated proteins was that the membrane

 

A.    maintained these molecules as a unit capable of reproduction and evolution

B.     provided sites for proteins to function

C.     transported material in and out of the compartment

D.     kept other molecules out of the compartment

 

4.     Organelles like mitochondria and chloroplasts are thought to have originated in eukaryotic cells by a process called

 

A.     phagocytosis

B.    endosymbiosis

C.     endocytosis

D.     autogenous formation

 

5.     Mitochondria and chloroplasts resemble bacteria in that they

 

A.     have their own DNA

B.     have their own ribosomes

C.     reproduce by simple division in two

D.    all of the above are true

 

6.     The resolving power of a good light microscope is

 

A.     0.2 mm

B.     0.2 µm

C.      0.2 nm

D.     0.2 Å

 

Name _________________________________                                          Biology 314

                                                                                                                        Exam 1 – 19 Jan 01

 

7.     What evolutionary relationship between the present-day eubacteria, archebacteria, and eukaryotes can be deduced from DNA sequencing?

 

A.     Eubacteria and archaebacteria are more closely related to each other than to eukaryotes.

B.     Archaebacteria and eukaryotes are more closely related to each other than to eubacteria.

C.     Eubacteria and eukaryotes are more closely related to each other than to archaebacteria.

D.    All three groups diverged at about the same time and are therefore equally distant from each other

 

8.     Electron microscopes have an advantage over light microscopes because electron microscopes

 

A.     allow you to examine living cells

B.     have a larger objective aperature

C.     are easier to use

D.    use a shorter wavelength

 

9.     The currently accepted model of membrane structure is called the

 

A.     lipid bilayer model

B.     unit membrane model

C.     lipoprotein model

D.    fluid mosaic model

 

10.   Proteins are attached to membranes by all but which one of the following:

 

A.     spanning the membrane as a transmembrane protein

B.     covalent links to membrane lipids

C.    hydrophobic amino acids associating with one-half of the phospholipid bilayer

D.     non-covalent bonds with transmembrane proteins

 

11.   Which types of molecules can readily cross the lipid bilayer?

 

A.     Small, charged molecules

B.    Small, uncharged molecules

C.     Large or small, uncharged molecules

D.     All of the above

 

12.   When cell components are separated by centrifugation at progressively higher speeds, that method is called

 

A.    differential centrifugation

B.     velocity centrifugation

C.     density-gradient centrifugation

D.     equilibrium centrifugation

Name _________________________________                                          Biology 314

                                                                                                                        Exam 1 – 19 Jan 01

 

13.   Gregor Mendel discovered the principles of genetics in his early experiments on

 

A.     protozoa

B.     fruit flies

C.    peas

D.     mice

 

14.   During the formation of haploid eggs and sperm, one member of each chromosome pair is separated to each cell in a type of cell division called

 

A.     mitosis

B.    meiosis

C.     cytokinesis

D.     gametogenesis

 

15.   The distance between linked genes can be estimated by the frequency of

 

A.    recombination

B.     mutation

C.     fusion

D.     transformation

 

16.   When thymine and adenine interact within the DNA molecule, they form

 

A.    two hydrogen bonds

B.     three hydrogen bonds

C.     nucleotide triphosphates

D.     phosphodiester bonds

 

17.   An experiment in which cells were grown in 15N after growth in 14N and their DNA was then separated by density gradient centrifugation demonstrated that

 

A.     DNA is replicated by DNA polymerase

B.     DNA replication is conservative

C.    DNA replication is semiconservative

D.     DNA forms double helices by hydrogen bonding between base pairs

 

18.   In the base pairing within a DNA double helix

A.     purine pair with purines

B.     A pairs with U and G pairs with C

C.     A pairs with G and C pairs with T

D.    A pairs with T and G pairs with C

Name _________________________________                                          Biology 314

                                                                                                                        Exam 1 – 19 Jan 01

 

19.   RNA molecules that serve as templates for protein synthesis are called

 

A.     transfer RNAs

B.    messenger RNAs

C.     ribosomal RNAs

D.     cytoplasmic RNAs

 

20.  Which of the following deletions will not change the reading frame of a gene?

 

A.     One nucleotide

B.     Two nucleotides

C.    Three nucleotides

D.     Four nucleotides

 

21.   How many different amino acids does the genetic code encode?

 

A.     16

B.    20

C.     24

D.     64

 

22.  Because the genetic code usually has more than one codon for each amino acid, the code is said to be

 

A.     redundant

B.     wobbly

C.     a template

D.    degenerative

 

23.  Plasma membrane phospholipids are

 

A.     located mostly in the outer leaflet of the bilayer.

B.     located mostly in the inner leaflet of the bilayer.

C.     symmetrically distributed between the two membrane halves.

D.    asymmetrically distributed between the two membrane halves.

 

24.  Bacteria can evolve faster than animals chiefly because

 

A.    they reproduce more frequently

B.     they can carry out a much wider range of chemical reactions

C.     they inhabit a wide range of habitats

D.     they possess cell walls

 

 

Name _________________________________                                          Biology 314

                                                                                                                        Exam 1 – 19 Jan 01

 

 

True or False (2 points each) – place a T or F in front of the answer

 

__T__  25.  Similarities in basic cellular mechanisms indicate that all present-day cells on Earth

descended from a single primordial ancestor.

 

___F_  26.  Photosynthesis first evolved in eukaryotic green algae.

 

___F_  27.  Higher plants and higher animals are similar in that they contain about the same number of

different cell types.

 

___T_  28.  Yeasts are simple eukaryotes.

 

___T_  29.  Robert Hooke first coined the term “cell” following his observation of the pattern of cell

walls in cork with a light microscope.

 

___F_  30.  Because the wavelength of electrons is 100,000 times shorter than the wavelength of

visible light, the resolution of the electron microscope is 100,000 times better.

 

__T__  31.  A single, somatic plant cell in culture is capable of forming an entire plant.

 

__F__  32.  Viruses are complexes of nucleic acid and protein that can replicate on their own.

 

__F__  33.  DNA contains the base uracil whereas RNA contains the base thymine.

 

__T__  34.  Compared to humans, E. coli has about a thousand times less DNA.

 

__F__  35.  In velocity centrifugation, a suspension is layered on top of a sucrose density gradient and

centrifuged until the density of the particles matches the density of the sucrose solution.

 

__T__  36.  Scanning electron microscopy is usually used for a 3-D view of the surface of cells.

 

__T__  37.  Cholesterol is an amphipathic molecule.

 

__T__  38.  RNAs can be enzymes.

 

__T__  39.  If 30% of the bases on a single strand of DNA are T, then 30% of the bases are A.

           

__F__  40.  Mitochondria and chloroplasts are both surrounded by single membranes.

 

 

Name _________________________________                                          Biology 314

                                                                                                                        Exam 1 – 19 Jan 01

 

41.   (4 points)  From the list below, select the TWO cellular structures that are found in all cells. 

 

A.     Nucleus

B.    Cytosol

C.     Mitochondria

D.     Chloroplasts

E.    Plasma membrane

F.   Endoplasmic reticulum

 

 

42.  (4 points)  What is the central dogma of molecular biology?

 

 

                        DNA à RNA à  Protein

 

 

 

 

 

43.   (6 points)  Name the membrane-bounded compartment in a eukaryotic cell where each of the

functions listed below takes place.

 

            A.  Photosynthesis                                                        ___Chloroplast_____________

 

            B.  Transcription                                                          ___Nucleus________________

 

C.  Oxidative Phosphorylation                                       ___Mitochondria (on)_________

 

            D.  Sorting and transporting proteins                           ___Golgi_________________

 

            E.  Synthesis of most cell membrane components         ___ER (endoplasmic reticulum)__

 

            F. Breakdown of unwanted molecules                             _Lysosome or Peroxisome or Vacuole_

 

 

44.  (4 points)  List 4 ways in which RNA is different from DNA

 

 

DNA                               RNA            

Thymine                          uracil

Deoxyribose                     Ribose

Double-stranded                Single-stranded

Nuclear                           Primarily cytoplasmic