Cell 101 Exam Ii Questions

Front 1

What is used to classify prokaryotes?

Back 1

1. photosynthetic or nonphotosynthetic
2. motile or nonmotile
3. unicellular or colony-forming or filamentous
4 formation of spores or divison by transverse binary fission

Front 2

A characteristic feature of the plasma membrane of prokaryotes is the prescence of what?

Back 2

invaginated regions

Front 3

Heterotrophs that harvest energy from organic molecules are called what?

Back 3

chemoheterotrophs

Front 4

Prokaryotes differ from eukaryotes in most characteristics besides what?

Back 4

The plasma membrane

Front 5

A microbiologist is investigating the effects of cold on a particular bacterium. He notices that as the temperature approaches zero degrees Centigrade, that the bacterium begins to

Back 5

form endospores

Front 6

Tuberculosis remains a serious world-wide health problem due to

Back 6

1. Transmission through the air
2. Social factors such as crowding and poverty
3. The increasing prevalence of HIV infections
4. It is multi-drug resistant

Front 7

A microbiologist is conducting a research project on chemoautotrophs. This means that the investigator is examining certain aspects of a bacterium that

Back 7

can oxidize sulfur and other inorganic substances to get energy

Front 8

The disease sometimes referred to as the "silent STD" because it is usually asymptomatic in women early on is

Back 8

chlamydia

Front 9

Chancre is a sore that is formed due to

Back 9

nfection with Treponema pallidum

Front 10

Most viruses form a capsid around their nucleic acid core. This capsid is composed of

Back 10

a protein

Front 11

Virulent viruses multiply within infected cells and eventually

Back 11

cause lysis of the host cell, releasing new viruses

Front 12

The genetic alteration of a cell’s genome by the introduction of foreign DNA is called

Back 12

transformation

Front 13

Recently a class of infectious proteins with no associated nucleic acid, have been identified. They are referred to as

Back 13

prions

Front 14

The HIV virus is considered a ______ virus, because after getting integrated into the host cell chromosomes, it does not begin replicating immediately.

Back 14

latent

Front 15

Each HIV particle possesses a ___________ on its surface that precisely fits a cell-surface marker protein called CD4 on the surfaces of the immune system cells called macrophages and T cells.

Back 15

glycoprotein

Front 16

Phages are viruses which can infect

Back 16

bacteria

Front 17

Viruses that become established as stable parts of the host cell genome are called

Back 17

temperate

Front 18

The infection cycle of HIV includes what steps?

Back 18

attachment, entry into cells, replication, integration into the host cell's DNA, production of new viruses, and finally exit from the cells.

Front 19

The onset of AIDS is often accompanied by

Back 19

a steep drop in T cell numbers

Front 20

A layer of lipoprotein and glycoprotein that covers the outer surface of some viruses is the

Back 20

envelope

Front 21

What are the major characteristics of viroids?

Back 21

1. Naked RNA molecules
2. Only a few 100 nucleotides long
3. Important infectious diseases in plants

Front 22

Question 13 text Scientists have demonstrated that the cholera bacteria, Vibrie cholerae, exist in at least two forms. It usually exists in a rather harmless form, however a phage conversion can occur which produces a disease-causing, virulent form. This conversion is caused by

Back 22

the phage introducing a gene into the bacterium's chromosome that codes for the cholera toxin which can cause death in humans

Front 23

Viruses infect every organism that has been investigated for their presence. However, viruses can only replicate in

Back 23

a very limited number of the host’s cells

Front 24

Viruses may cause cancer by

Back 24

triggering the expression of cancer-causing genes present in the genome

Front 25

The _________________________ viruses have been linked with liver cancer in people with chronic infections.

Back 25

Hepatitis B and C

Front 26

Located on or within the cell are _________ proteins, each of which has a three dimensional shape complementary to that of a specific signal molecule.

Back 26

receptor

Front 27

The space into which neurotransmitters are released is called a chemical

Back 27

synapse

Front 28

Cyclic AMP and calcium ions are often used within a cell as

Back 28

secondary messengers

Front 29

The cells of multicellular organisms use a variety of molecules as signals which are

Back 29

proteins, individual amino acids, nucleotides, steroids, other lipids, and dissolved gases

Front 30

Signals with short-lived, local effects are called

Back 30

paracrine signals

Front 31

Synaptic signaling requires

Back 31

neurotransmitters

Front 32

The molecules that convert extracellular signals into intracellular ones are

Back 32

cell surface receptors

Front 33

Do chemically gated ion channels have genes incoded in them?

Back 33

No

Front 34

The class of cell surface receptors that act indirectly on plasma membrane-bound enzymes or ion channels are called

Back 34

G proteins

Front 35

A small number of surface receptors can ultimately generate a large intracellular response, as each step of the pathway is often expanded by

Back 35

signal amplification

Front 36

Most cells are in physical contact with other cells at all times by forming permanent connections called

Back 36

cell junctions

Front 37

In the digestive tract adjacent cells develop connections to form a sheet that prevents leakage of small molecules. These connections between cells are called

Back 37

tight junctions

Front 38

Small molecules or ions can pass from one cell to another through

Back 38

communicating junctions

Front 39

Junctions in which the cytoskeleton of a cell is attached to that of other cells or the extracellular matrix are called

Back 39

anchoring junctions

Front 40

A biochemist is designing a new drug that will mimic the shape of a particular signal molecule. She has to design the drug molecules so that they will be selected over the other “normal” molecules at the surface of the cell membrane. Therefore she must produce molecules that will bind to the receptor protein and

Back 40

induce a change in the receptor molecule shape, which will ultimately produce a cellular response

Front 41

What technique has recently aided the study of receptor proteins?

Back 41

monoclonal antibodies

Front 42

What occurs during autocrine signaling?

Back 42

Signal molecules are released from a cell and bind to receptors on its own plasma membrane.

Front 43

Intracellular receptors usually bind to

Back 43

lipid-soluble signals.

Front 44

What are the different types of cell surface receptors?

Back 44

chemically gated ion channels, enzymic receptors, and G-protein linked receptors

Front 45

What things are used as secondary messengers?

Back 45

cyclic adenosine monophosphate, calcium ions, and cAMP

Front 46

What does the amplification of a cellular signal require?

Back 46

a second messenger,a signal molecule, and a cascade of protein kinases

Front 47

MHC proteins are

Back 47

identity markers present on the surface of an individual's cells.

Front 48

Sheets of cells are formed from which type of cell junctions?

Back 48

tight junctions

Front 49

Cadherin can be found in what type of cell junction?

Back 49

anchoring junctions

Front 50

Plasmodesmata are a type of what junction?

Back 50

communicating junction.

Front 51

Viruses consist of a ________________ core surrounded by a protein coat.

Back 51

nucleic acid

Front 52

Phages infect bacterial cells by

Back 52

poking holes in the cell and injecting their DNA.

Front 53

The end result of the viral lytic cycle is

Back 53

the release of new viruses.

Front 54

The alteration of a cell's genome by the incorporation of foreign DNA is called

Back 54

transformation.

Front 55

What are the viral glycoproteins that play a role in the infection of human cells by HIV?

Back 55

CD4 and CCR5

Front 56

The HIV enzyme, ________________, produces a DNA copy of the viral genome once it is inside the host cell.

Back 56

reverse transcriptase

Front 57

The drug AZT and its analogs functions by

Back 57

inhibiting the replication of viral nucleic acid.

Front 58

What is the function of the CD8+ cell antiviral factor (CAF) in human white blood cells?

Back 58

blocks replication of the HIV virus

Front 59

New strains of flu viruses are most likely to arise in the Far East because

Back 59

common hosts (ducks, chickens, pigs) live in close proximity to humans.

Front 60

Which of the following infectious agents does not contain protein?

Back 60

viroids

Front 61

Once they evolved, _____________ forever changed the atmosphere on earth.

Back 61

cyanobacteria

Front 62

Are prokaryotic cells unicellular or multicellular?

Back 62

unicellular

Front 63

When bacterial cell walls are covered with an outer membrane of lipopolysaccharide, they are

Back 63

gram-negative

Front 64

The prokaryotic genome is contained in the

Back 64

nucleoid region.

Front 65

Archaebacteria and bacteria do not differ in their

Back 65

presence in nonextreme environments.

Front 66

Genetic recombination has led to antibiotic resistance through the transfer of

Back 66

plasmids.

Front 67

Prokaryotic organisms that obtain their energy by oxidizing inorganic substances are called

Back 67

chemoautotrophs.

Front 68

What disease is experiencing new outbreaks because of antibiotic resistance?

Back 68

tuberculosis

Front 69

The disease sometimes referred to as the "silent STD" because it is usually asymptomatic in women early on is

Back 69

chlamydia

Front 70

What tasks can be attributed to bacteria?

Back 70

decomposition of dead organic matter, increasing oxygen levels in the atmosphere, and production of antibiotics

Front 71

An atom gains energy when

Back 71

it undergoes reduction.

Front 72

Which of the following is concerned with the amount of energy in the universe?

Back 72

the First Law of Thermodynamics

Front 73

In a chemical reaction, if ΔG is negative, it means that

Back 73

the reaction will proceed spontaneously.

Front 74

A catalyst does what?

Back 74

lowers the amount of energy needed for a reaction to proceed.

Front 75

Do all the cells of an organism contain the same enzymes?

Back 75

No, this is false.

Front 76

A multienzyme complex contains

Back 76

enzymes that catalyze a series of reactions.

Front 77

What are factors that can have an effect on the rate of enzyme-catalyzed reactions?

Back 77

temperature, ph, and concentration of substrate

Front 78

How is ATP used in the cell to produce cellular energy?

Back 78

ATP hydrolysis is coupled to endergonic reactions.

Front 79

Anabolic reactions are reactions that

Back 79

make chemical bonds.

Front 80

How is a biochemical pathway regulated?

Back 80

The end product inhibits the first enzyme in the pathway by binding to an allosteric site.