Biology 122 mini exam 2

Approximately how many people worldwide are infected with AIDS?

30 million
60 million
90 million
120 million

60 million

You are an epidemiologist studying a new disease very similar to AIDS. Most likely, this new disease is caused by what?

a retrovirus
a parasite
a bacterium
a genetic mutation

retrovirus

Which of the following is true?

Kaposi’s sarcoma is only seen in AIDS patients.
Kaposi’s sarcoma causes AIDS.
Kaposi’s sarcoma is a drug to treat AIDS.
Kaposi’s sarcoma is a symptom of AIDS.

Kaposi’s sarcoma is a symptom of AIDS.

AIDS can be contracted by contact with which of the following?

semen or tears
blood or semen
tears or vaginal secretions
saliva or blood

blood or semen

How long must AIDS patients take their medication?

Until the disease is gone.
For the rest of their life.
Until their white blood cell count is normal.
Up to 5 years.

For the rest of their life.

How does HIV cause disease?

HIV kills red blood cells.
HIV mutates host DNA and causes cancer.
HIV kills cells that defend the body against disease.
HIV kills brain cells.

HIV kills cells that defend the body against disease.

How do enveloped viruses differ from nonenveloped viruses?

They have a protein coat.
They have a membrane-like outer covering.
They are too small to see with a light microscope.
They have a capsid.

They have a membrane-like outer covering.

Which replicative cycle describes a virus that can integrate its genome into the host cell’s genome?

Lytic
Lysogenic
Mutagenic
Viral

Lysogenic

Which enzyme inserts viral DNA into the host’s chromosomal DNA?

Protease
DNA polymerase
Reverse transcriptase
Integrase

Integrase

How does HIV bind to a host cell?

CD4 binds to the viral capsid on the cell surface.
CD4 binds to a co-receptor on the cell surface.
The viral envelope proteins interact with gp120 on the host-cell membrane.
The viral envelope proteins interact with CD4 and a co-receptor on the cell membrane.

The viral envelope proteins interact with CD4 and a co-receptor on the cell membrane.

Which of the following events stimulates the production of viral particles in a host cell?

Activation of the host cell by cytokines, growth factors, or antigens.
Processing of viral envelope proteins at the Golgi.
Low-level transcription of viral DNA.
Assembly of viral proteins and mRNA molecules.

Activation of the host cell by cytokines, growth factors, or antigens.

True or false? The human immunodeficiency virus (HIV) uses reverse transcriptase to make double-stranded RNA copies of its DNA genome.

True
False

False

The genetic material of HIV consists of _____.

single-stranded RNA
double-stranded DNA
double-stranded RNA
none of the above
single-stranded DNA

Single-stranded RNA

Which of these binds to receptor molecules on the host cell membrane?

B
D
E
C
A

A

What is the function of reverse transcriptase?

catalyzing the formation of RNA from a DNA template
catalyzing the formation of DNA from a polypeptide template
catalyzing the formation of a polypeptide from a RNA template
catalyzing the formation of RNA from a polypeptide template
catalyzing the formation of DNA from a RNA template

catalyzing the formation of DNA from an RNA template

What is the source of a viral envelope?

viral glycoproteins
host cell membrane
prophages
provirus
host cell DNA

host cell membrane

Which of these is reverse transcriptase?

D
B
E
A
C

C

Which of these is the viral genome?

D
B
A
E
C

E

Double-stranded viral DNA is incorporated into a host cell as a _____.

homeoboxes
provirus
promoter
transposon
lac

provirus

In the lysogenic cycle _____.

host DNA is destroyed and viral DNA is replicated
a bacterium replicates without passing viral DNA to its daughter cells
viral DNA is destroyed and host DNA is replicated
a bacterium divides once before the lytic cycle is initiated
viral DNA is replicated along with host DNA

viral DNA is replicated along with host DNA

Cycle A is the _____ cycle and cycle B is the _____ cycle.

lytic … lysogenic
lytic … phage
lysogenic … phage
lysogenic … lytic
phage … lysogenic

lytic … lysogenic

Where do retroviruses carry their genetic material?

RNA
both RNA and DNA
DNA
Either DNA or RNA depending on the type of retrovirus.

RNA

H.I.V. evolved from a virus that infects what species?

ring-tailed lemur
chimpanzee
gorilla
orangutan

chimpanzee

Which of the following is true?

The borna virus only targets mammals.
The borna virus only targets humans.
The borna virus only targets primates.
The borna virus only targets mammals and birds.

The borna virus only targets mammals and birds.

Your dog is lacking syncytin. It will not be able to properly form what?

estrogen
insulin
a placenta
saliva

a placenta

The lytic cycle of bacteriophage infection ends with the _____.

replication of viral DNA
entry of the phage protein coat into the host cell
assembly of viral particles into phages
the injection of phage DNA into a bacterium
rupture of the bacterium

rupture of the bacterium

The pointer is indicating the _____.

viral envelope
viral nucleic acid genome
bacterium’s nucleic acid genome
viral protein coat
bacterium’s plasma membrane

viral protein coat

As a result of the lytic cycle, _____.

the host cell is not destroyed
the host cell’s DNA is destroyed
viral ribosomes are produced
viral DNA is incorporated into host cell DNA
a prophage is created

the host cell’s DNA is destroyed

A disease that spreads rapidly around the world is called a(n) ___________.

anthrodemic
pandemic
endemic
transdemic

pandemic

A new disease emerges and exists only as a free-floating virus. Which of the following will make antibiotics against this?

macrophages
lymphokines
B cells
T cells

B cells

What kind of cell can recognize infected cells and kill them directly?

macrophages
lymphokines
T cells
B cells

T cells

You are an immunologist working on a new flu vaccine that attacks molecules with the same basic make-up as hemagglutinin. What is your area of expertise?

fats
carbohydrates
nucleic acids
proteins

proteins

The best flu vaccine would work to prevent people from which of the following?

Influenza A, B, and C
Influenza A
Influenza A and B
Influenza A, B, C, and D

Influenza A, B, and C

Which of the following is not a type of primary meristematic cell found in apical meristems?

Procambium
Vascular cambium
Protoderm
Ground meristem

Vascular cambium

Which structure determines the direction of root growth by sensing gravity?

Mucigel
Pith
Root cap
Root hairs

root cap

True or false? Plant growth involves both the production of new cells by mitosis and the expansion of cell volume.

True
False

true

Which of the following statements about the vascular cambium is true?

It is a layer of undifferentiated cells that develops into secondary xylem and phloem.
It is a type of apical meristem.
It is located between the primary xylem and cortex.
It develops into cork cells on the outside of the cortex.

It is a layer of undifferentiated cells that develops into secondary xylem and phloem.

Why do plants need secondary growth?

To produce new leaves
To grow taller
To produce a more extensive root system
To provide structural support for the plant

to provide structural support for the plant

Which of the following parts of a plant remains on the plant even after several years of growth?

Primary phloem
Cortex
Primary xylem
Epidermis

primary xylem

True or false? Primary growth can occur at both the apical and lateral meristems at the tips of the roots and stems in a plant.

True
False

false

Secondary growth NEVER occurs in _____.

roots and leaves
leaves
stems and leaves
stems
roots

leaves

_____ provides cells for secondary growth.

Apical meristem
Secondary xylem
Vascular cambium
The root
Secondary phloem

vascular cambium

Vascular cambium forms wood toward the stem’s _____ and secondary phloem toward the stem’s _____.

surface … surface
surface … center
center … center
top … bottom
center … surface

center … surfance

What is the function of cork?

providing a site for photosynthesis
insulation and waterproofing
providing cells for secondary growth
providing cells for primary growth
regulating the opening and closing of stomata

insulation and waterproofing

How is the supply of vascular cambium maintained?

by the division of its cells
by the differentiation of secondary phloem
by the differentiation of cork
by the differentiation of secondary xylem
by the differentiation of apical meristem

by the division of its cells

In leaves, chloroplasts are found in _____.

phloem
cuticle
guard cells
palisade mesophyll
xylem

palisade mesophyll

The region surrounded by guard cells is indicated by the letter _____.

D
E
A
C
B

D

Which tissue acts as a filter on the water absorbed by root hairs?

Cortex
Endodermis
Epidermis
Vascular tissue

endodermis

True or false? Root pressure can move water a long distance up the xylem because of the higher water potential of the xylem in comparison to the water potential in the surrounding cells.

True
False

False

Which of the following statements about the distribution of sap throughout a plant is true?

The driving force for sugar movement is transpiration.
The mechanism that explains the movement of sugars throughout a plant is called the pressure-flow hypothesis.
The main component of phloem sap is glucose.
Companion cells form the conducting tissue for sap.

The mechanism that explains the movement of sugars throughout a plant is called the pressure-flow hypothesis.

Which term describes an area where sugars are used or stored?

Sink
Source
Stomata
Leaves

sink

Which of the following statements about xylem transport is true?

Water and minerals move through the root cortex into the xylem and upward through the stem and into leaves.
Water and minerals enter the xylem by diffusion.
All water transported by the xylem is used for photosynthesis in the leaves.
The xylem cells that conduct water and minerals are alive.

Water and minerals move through the root cortex into the xylem and upward through the stem and into leaves.

What characterizes the rates of photosynthesis and transport in a plant on a dry cloudy day?

The photosynthesis rate is low and stomata are open.
The photosynthesis rate is high and phloem transport rates are low.
Both the photosynthesis and transpiration rates are low.
Both the photosynthesis and transpiration rates are high.

Both the photosynthesis and transpiration rates are low.

True or false? The rate of sugar transport in a plant depends on the rate of photosynthesis, the rate of transpiration, and the difference in turgor pressure between the source and the sink.

True
False

False

The channels indicated by the pointer, are _____.

plasmodesmata
gap junctions
desmosomes
tight junctions
mycorrhizae

plasmodesmata

Which of these are symbiotic associations?

apoplasts
Casparian strips
symplast
mycorrhizae
root hairs

mycorrhizae

In roots the _____ forces water and solutes to pass through the plasma membranes of _____ cells before entering the _____.

xylem … endodermis … Casparian strip
Casparian strip … endodermis … xylem
Casparian strip … ectoderm … xylem
Casparian strip … endodermis … phloem
transpiration … endodermis … xylem

Casparian strip…endodermis…xylem

_____ provide(s) the major force for the movement of water and solutes from roots to leaves.

Bulk flow
Transfer cells
Transpiration
Translocation
Root pressure

transpiration

_____ bonds are responsible for the cohesion of water molecules.

Hydrogen
Ionic
Peptide
Nonpolar covalent
Polar covalent

hydrogen

_____ cells are the cells that regulate the opening and closing of stomata, thus playing a role in regulating transpiration.

Sieve-tube member
Companion
Tracheid
Guard
Casparian strip

guard