Lecture Exam 1 with Answers

Question 1

Which are the three currently accepted domains?

A. Archaea, Bacteria, and Eukarya
B. Archaea, Prokaryota, and Eukaryota
C. Bacteria, Fungi, and Protista
D. Bacteria, Prokaryota, and Eukarya

Answer 1

A. Archaea, Bacteria, and Eukarya

Question 2

The current widely accepted estimates for the origin of life on earth and formation of earth are (in years: life and earth):

a) 3.6 x 107 and 4.6 x 107
b) 3.6 x 108 and 4.6 x 108
c) 3.6 x 109 and 4.6 x 109
d) 3.6 x 1010 and 4.6 x 1010

Answer 2

c) 3.6 x 109 and 4.6 x 109

Question 3

Which of the following are arranged from smallest to largest?
a) nano, micro, milli, kilo
b) micro, nano, milli, kilo
c) 10-6, 10-7, 10-8
d) ribosome, lipid molecule, water molecule

Answer 3

a) nano, micro, milli, kilo

Question 4

The FIRST self-replicating systems likely contained which molecule(s) as a central
component?
a. polysaccharides
b. D N A
c. R N A
d. Protein

Answer 4

c. R N A

Question 5

Bacteria are generally identified to species by using which of the following?
A. a combination of genetic, biochemical, and microscopic approaches
B. a combination of microscopic and physiological approaches, but not genetics
C. primarily characteristics such as motility that can be visualized using microscopy
D. primarily morphological characteristics of individual cell

Answer 5

A. a combination of genetic, biochemical, and microscopic approaches

Question 6

The categorization of cells into “three domains” of life was originally based on what evidence?
a) Cell membrane differences
b) Genome size differences
c) Small subunit ribosomal rRNA comparison
d) Large subunit ribosomal rRNA comparison
e) Amino acid sequence comparison

Answer 6

c) Small subunit ribosomal rRNA comparison

Question 7

Which is the best description of the primary purpose of a phylogeny?
A. Phylogenies show all the alterative names for each species.
B. Phylogenies show all the common names for each species.
C. Phylogenies show evolutionary relatedness between organisms.
D. Phylogenies show interactions between species in a shared habitat

Answer 7

C. Phylogenies show evolutionary relatedness between organisms.

Question 8

Which of the following taxonomic ordering is correct (either top to bottom or bottom to top)? A) domain, phylum, class, order, family, genus, species
B) domain, phylum, order, class, family, genus, species
C) domain, order, phylum, class, genus, species
D) species, genus, family, order, domain, class, phylum
E) species, genus, family, order, class, domain, phylum

Answer 8

A) domain, phylum, class, order, family, genus, species

Question 9

Once several different but related sequences are obtained, which step must be performed BEFORE a phylogenetic tree is constructed?

  A) cladistics
  B) parsimony
  C) sequence alignment
  D) threshold scoring

Answer 9

C) sequence alignment

Question 10

Which term refers to proteins that extend across the plasma membrane from one side to the other?

  A) glycoproteins
  B) lipoproteins
  C) peripheral proteins
  D) transmembrane proteins

Answer 10

D) transmembrane proteins

Question 11

in which types of organisms are phospholipids with branched chains common?

  A) archaea
  B) bacteria
  C) eukaryotes
  D) all of the above

Answer 11

A) archaea

Question 12

The lipopolysacharide molecule is an important component of the cell membranes of which organisms?

  A) archaeans 
  B) eukaryotes
  C) gram-negative bacteria
  D) gram-positive bacteria

Answer 12

C) gram-negative bacteria

Question 13

Bacteria use flagella to move purposefully toward or away from a chemical by which of the following?

  A) having alternating runs and tumbles of equal lengths
  B) increasing the length of runs and decreasing the length of tumbles
  C) increasing the length of tumbles and decreasing the length of tumbles
  D) using only runs

Answer 13

B) increasing the length of runs and decreasing the length of tumbles

Question 14

Which of the following is not a typical difference between eukaryotes and prokaryotes?

  A) eukaryotes have ester-linked phospholipids, whereas prokaryotes have ether-linked or ester-linked phospholipids
  B) eukaryotic cell walls lack peptidoglycan in their cell walls (if present), whereas many prokaryotes use peptidoglycan in their cell walls
  C) eukaryotic cells have histones for DNA organization, whereas prokaryotic cells have his tone-like proteins or nucleotide-associated proteins involved in DNA organization 
  D) eukaryotic cells typically have circular chromosomes, whereas prokaryotic cells typically have linear chromosomes

Answer 14

D) eukaryotic cells typically have circular chromosomes, whereas prokaryotic cells typically have linear chromosomes

Question 15

Which of the following is not true of archaeal membranes?

  A) they are sometimes monolayers
  B) they have branched phospholipids
  C) they have ether linkages instead of ester linkages
  D) they have peptidoglycan linkages attaching their membranes to their cell wall

Answer 15

D) they have peptidoglycan linkages attaching their membranes to their cell walls

Question 16

Which of the following does NOT generally apply to the bacterial cell wall?

  A) it is composed of alternatin NAG and NAM residues 
  B) determine cell shape
  C) its material is called peptidoglycan or Murien
  D) it is an important target for antibodies
  E) he murein subunits are cross linked are cross linked by peptides, proving cell wall strength

Answer 16

B) determine cell shape

Question 17

Which of the following statements about active transport is true?

  A) it chemically modifies the molecules it carries
  B) it is the same as facilitated diffusion
  C) it can result in the net movement of molecules from a Edison of low concentration to high concentration 
  D) it does not require ATP or proton motive force as a source of energy
  E) it always requires a siderophore

Answer 17

C) it can result in the net movement of molecules from a Edison of low concentration to high concentration

Question 18

Which of the following is not a component of the bacterial cytoskeleton?
A) actin
B) FtsZ
C) MreB
D) Crecentin

Answer 18

A) actin

Question 19

Which of the following statements concerning vacuoles is TRUE?
A)they can pressurize gas
B) the membrane surrounding them is a phospholipids bilayer
C) they are found only in archaea
D) they provide buoyancy

Answer 19

D) they provide buoyancy

Question 20

Pili and filmbriae have similar structures. The two terms were once used interchangeably. Which of the following statements about their function is FALSE?
A) allow transfer of DNA between bacterial cells
B) can be involved in movement
C) can be very abundant and are present across the entire surface of the cell
D) are typically longer and thicker than the flagella
E) are important for attachment to surfaces

Answer 20

D) are typically longer and thicker than the flagella

Question 21

The cell walls of gram-positive bacteria contain charged molecules called _____________, which are partially responsible for the _________ charge of the cell surface.
A) positive/ diaminopumelic acids
B) negative/ phospholipids
C) negative/ teichoic acids
D) positive/ LPS
E) negative/ porin

Answer 21

C) negative/ teichoic acids

Question 22

Which of the following is not a macronutrient?
A) carbon
B) zinc
C) phosphorus
D) calcium
E) sulfur

Answer 22

B) zinc

Question 23

Spirulina are Cyanobacteria that use light as an energy source, water as an electron source, and CO2 as a carbon source. Which type of metabolism do these organisms possess?
A) photolithoeretroph
B) chemoorganoheterotroph
C) photoorganoheterotroph
D) photolithoautotroph
E) not enough information to determine which type

Answer 23

D) photolithoautotroph

Question 24

Chemotrophs obain their energy from which of the following?
A) Inorganic chemical reactions only
B) light energy
C) organic chemical reactions only
D) organic and inorganic chemical reactions

Answer 24

D) organic and inorganic chemical reactions

Question 25

Which of the following is FALSE concerning growth factors for microorganisms?
A) they are organic compounds
B) not all microorganisms require growth factors
C) vitamins can be growth factors
D) glucose is considered to be a growth factor because microorganisms can grow on sugars
E) growth factors for specific microbes must be supplied by the environment for those microbes to survive and reproduce

Answer 25

D) glucose is considered to be a growth factor because microorganisms can grow on sugars

Question 26

Which statement concerning the bacterial cell cycle is FALSE?
A) it is the sequence of events from the formation of a new cell through the next cell division
B) the pathways of (i) DNA replication and partitioning, and (ii) cytokinesis each use function
C) it is known as mitosis
D) generally, bacteria must increase in size to initiate a new cell cycle
E) defects in genes important in the cell cycle can cause cells to grow as filaments

Answer 26

C) it is known as mitosis

Question 27

You have an exponentially growing batch culture of bacteria that at “time 0” contains 1x10^5 bacteria. the generation time is 2 hr. Following 6 hr of additional exponential growth after “time 0”, how many bacteria will there be in the culture?
A) 8 x 10^5
B) 4 x 10^5
C) 3 x 10^5
D) 2 x 10^5
E) 1 x 10^5

Answer 27

A) 8 x 10^5

Question 28

Which of the following is another term for generation time?
A) doubling time
B) lag phase
C) mitotic index
D) replication index

Answer 28

A) doubling time

Question 29

Which of the following best describes FtsZ?
A)a cytoskeletal protein in eukaryotic cells
B) the protein that assembles the Z ring, which forms a divisive before division by binary fission
C) the protein that forms within the central structure of the new cell wall and septum that separates the daughter cells during binary fission
D) the protein that gives structure to spirochetes, contributing to their unusual shape and motility

Answer 29

B) the protein that assembles the Z ring, which forms a divisive before division by binary fission

Question 30

Which structure separates new daughter cells in binary fission?
A) the crescent
B) the division septum
C) the FtsZ
D) the spindle apparatus

Answer 30

B) the division septum

Question 31

Which of the following are not types of inclusions in bacterial cells?
A) carboxysomes
B) magnetosomes
C) flagella
D) volutin granules

Answer 31

C) flagella

Question 32

During flagellar-mediated motility, when the flagellation spin clockwise, the bacterium tumbles. What do you predict is the consequence of reversing the spin direction?
A) the bacterium tumbles more slowly
B) the bacterium tumbles more quickly
C) the bacterium moves forward
D) the flagella become tangled and the bacterium sinks
E) the flagella cannot reverse direction

Answer 32

C) the bacterium moves forward

Question 33

The nodes of a phylogenetic tree represent:
A) show where an ancestor diverged into two lineages
B) the number of changes that have occurred along that branch
C) the evolution of a new phenotype
D) a horizontal gene transfer event

Answer 33

A) show where an ancestor diverged into two lineages

Question 34

Three or four of the statements about cell walls in bacteria and archaea are correct. Which, if any, is FALSE?
A) the mechanical strength of peptidoglycan cell walls depends on covalent cross links that join adjacent glycan strands
B) N-acetylmuramic acid (NAM) is a component of the cell wall in bacteria and archaea
C) some bacterial species lack a cell wall
D) cell wall precursors are synthesized in the cytoplasm and transported across the plasma membrane
E) all of the above statements are correct

Answer 34

B) N-acetylmuramic acid (NAM) is a component of the cell wall in bacteria and archaea

Question 35

The term used to indicate that an organisms uses CO2 as its primary carbon source is:
A) heterotroph
B) prototroph
C) autotroph
D) lithotroph
E) chemotroph

Answer 35

C) autotroph