Practice Exam 3 Bio 180

Which of the following filaments is made from adding smaller protein subunits together?

All filaments

Which of the following will most likely increase the virulence of a bacterium?

A plasmid containing an antibiotic resistance, a capsule, and endotoxins

Which of the following locations would you find a intermediate filament

Finger-nail

Transversal Movement of phospholipids in the membrane is most commonly described as

Flipping from one monolayer to the opposite monolayer

Which of the following cytoskeletal proteins is not associated with a known motor protein?

Keratin

Which of the following words is not a term that is associated with Actin

Kinesin

Which of the following is NOT an advantage of internal membranes?

Greater control of mobility

Actin is a critical component of the "thin filament" found in all contractile muscle tissue. Which of the following motor proteins binds to actin to cause muscle contraction?

Myosin

Which of the following is true with respect to mitochondrial DNA? Mitochondrial DNA is single-stranded, circular DNA Mitochondrial DNA is inherited from both the mother and the father Mitochondrial DNA is likely the remnant of an ancient prokaryote, but does not contain any functional genes Mitochondrial DNA and chloroplast DNA contain the same genes None of the above are true All of the above are true

None of the above are true

Flagella to help virus move

Not present in any viruses

Plasmid

Not present in any viruses

Ribosomes for producing viral proteins

Not present in any viruses

Rotational Movement of phospholipids in the membrane is most commonly described as

Spinning around a vertical axis of rotation in the same monolayer

We sometimes use the term asymmetric to describe a membrane. What does this mean?

The inner surface of the membrane has a different look, feel, and function than the outside of the membrane.

Which of the following is the most probable fate of a newly emerging virus that causes rapid and high mortality in its host?

The newly emerging virus will die out rather quickly or will mutate to be far less lethal.

Which of the following analogies best describes the process of transformation?

Walking down the street, seeing a piece of used gum, and plopping it into your mouth

Though plants, fungi, and prokaryotes all have cell walls, we place them in different taxa. Which of these observations comes closest to explaining the basis for placing these organisms in different taxa, well before relevant data from molecular systematics became available?

b.Their cell walls are composed of very different biochemicals.

Mitochondria and Chloroplasts are similar in that...(mark all that apply)

b.They are both found in all plants d.They both contain their own DNA

What kinds of molecules pass through a cell membrane most easily?

b.small and hydrophobic

viral nucleic acids

copied from nucleic acids

Low pH of 5

lysosomes

Capsomeres

made by host ribosomes

Carl Woese and collaborators identified two major branches of prokaryotic evolution. What was the basis for dividing prokaryotes into two domains?

d.genetic characteristics such as ribosomal RNA sequences

Bacteria perform each of the following ecological roles. Which role typically does not involve a symbiosis (i.e. a physical association between two species)?

decomposer

Which statement about the genomes of prokaryotes is correct?

e.Prokaryotic genomes are composed of circular DNA.

The predatory bacterium, Bdellovibrio bacteriophorus, drills into a prey bacterium and, once inside, digests it. In an attack upon a gram-negative bacterium that has a slimy cell covering. What is the correct sequence of structures penetrated by B. bacteriophorus on its way to the prey's cytoplasm? 1. membrane composed mostly of lipopolysaccharide 2. plasma membrane 3. peptidoglycan 4. capsule

4, 1, 3, 2

A membrane protein has an alpha helix that crosses the bilayer and on the extracellular surface has several glycoproteins attached. Which is the best descriptor of this protein?

A transmembrane protein

Which of the following is true regarding BOTH mitochondria and chloroplasts?

Both organelles contain their own ribosomes

Determine if the statement in quotations is true or False. If false, identify one of the corrections below that make it a true statement. "The oligosaccharides that sometimes decorate membrane proteins are only found on the cytosolic monolayer of the plasma membrane."

Change cytosolic to extracellular

Which of the following best describes a plasmid?

Contains non-essential genes

The two monolayers of a biological membrane have the same phospholipid composition

False

Which of the following is true regarding centrosomes?

Function as microtubule organizing centers

Which statement about the domain Archaea is TRUE?

Genetic prospecting has recently revealed the existence of many previously unknown archaean species.

Select all of the appropriate terms that apply to the following organism: A prokaryote that obtains both energy and carbon as it decomposes dead organisms

Heterotroph, Chemtroph

Which of the following pairs of membrane protein descriptions is mutually exclusive meaning that if you are one you can't be the other?

Integral Membrane Protein and Peripheral Membrane Protein

Which of the following pairs has a relationship such that the second term is always a member of the first term. (i.e. Canine Family : dogs)

Integral membrane Proteins : Transmembrane Proteins

Which of the following activities can a temperate phage carry out that a virulent phage cannot?

Integration- viral DNA is spliced into host genome

In a classic membrane experiment, scientists chemically labelled phospholipids with photo labile fluorescent dye. (Photo labile means it is destroyed by light). Labelled cells were observed under a microscope and a small patch of the membrane was exposed to a laser that bleached the fluorescence. Over a 1 hour period the entire cell lost fluorescence. This experiment most likely supports which of the following movement hypotheses.

Lateral movement

Which of the following movements is common for a protein in a biological membrane? (choose all that apply)

Lateral movement, Rotational movement

What is the most common source of genetic diversity in prokaryotes?

Mutation

Which of the following statements is not true?

Only bacteria have histones associated with DNA.

Which of the following monolayers is called a cytosolic leaflet?

Outer layer of the organellular membrane

Which of the following organelles is NOT a member of the endomembrane system?

Peroxisomes

Capsid made from capsomere proteins

Present in ALL viruses

Nucleic Acid

Present in ALL viruses

Accessories proteins such as reverse transcriptase

Present only in some

Viral envelope made from host cell lipid bilayer

Present only in some

Site of phospholipid synthesis

Smooth ER

The inner membrane monolayer of organelle membranes is called the luminal leaflet

True

Which of these analogies best explains the difference between the cytosol and the cytoplasm

a.The cytoplasm is like Atlantic Ocean and the cytosol is like the sea water in it

The presence of cholesterol in the plasma membranes of some animals

a.enables the membrane to stay fluid more easily when cell temperature drops.

The genome of a bacterial cell is sequenced and several remnants of phage DNA are uncovered. The most likely explanation is

b.A transduction has occurred

A temperate phage goes dormant between which stages of the lytic cycle?

b.Entry and Synthesis

A prerequisite for undergoing conjugation is

c.An F factor

The best represented (most common) viral genome type is

c.Single Stranded RNA

A researcher lyses a cell that contains nucleic acid molecules and capsomeres of tobacco mosaic virus (TMV). The cell contents are left in a covered test tube overnight. The next day this mixture is sprayed on tobacco plants. Which of the following would be expected to occur?

c.The plants would develop the typical symptoms of TMV infection.

This bacterium derives nutrition by digesting human intestinal contents (in other words, food) away from any air. Thus, this bacterium should be an

c.anaerobic chemoheterotroph.

When a membrane is freeze-fractured, the bilayer splits down the middle between the two layers of phospholipids. In an electron micrograph of a freeze-fractured membrane, the bumps seen on the fractured surface of the membrane are

d. integral proteins.

Which of the following is characteristic of the lytic cycle?

d.A large number of phages are released at a time.

Water passes quickly through cell membranes because

e. it moves through aquaporins in the membrane (a hydrophilic channel).

Which of these are uniquely found in extracellular matrix or organelle lumen?

e.glycoproteins

Which cytoskeletal structure is most closely associated with the centrosome?

microtubule

In a hypothetical situation, a bacterium lives on the surface of a leaf, where it obtains nutrition from the leaf's non-living, waxy covering while inhibiting the growth of other microbes that are plant pathogens. If this bacterium gains access to the inside of a leaf, however, it causes a fatal disease in the plant. Once the plant dies, the bacterium and its offspring decompose the plant. What is the correct sequence of ecological roles played by the bacterium in the situation described here? Check those that apply.

nutrient recycler, mutualist, parasite

viral envelope

stolen from host membrane

The host range of a virus is determined by

the proteins on its surface and that of the host