1) which description best describes the cell wall of a gram-positive bacteria?
a. it is composed of a single plasma membrane and a thin outer layer of peptidoglycan.
b. it is composed of a double layer in the plasma membrane and a thin outer layer of
peptidoglycan.
c. it is composed of a double layer in the plasma membrane and a thick outer layer of
peptidoglycan.
d. it is composed of a single plasma membrane and a thick outer layer of peptidoglycan.
e. it is composed of a single plasma membrane and a thin outer layer of cellulose.
2) an animal with a simple netlike nervous system is the
a. earthworm.
b. cat.
c. hydra.
d. octopus.
e. planarian.
3) present experimental evidence related to griffith’s experiment and the identification
of the cell’s genetic material.
when experimenting with streptococcus pneumoniae in the 1920’s, griffith noticed that
some colonies were shiny and smooth and some were rough in appearance. he called
the shiny colonies, the s strain’ and the rough colonies, the r’ strain. when griffith
injected mice with the s strain, which he discovered were encapsulated, they died. when
he injected them with the r strain, they did not die. in trying to determine what factor
was responsible for the s strain’s virulence, griffith heat-killed the s bacteria to destroy
the capsule. when he injected mice with the normally fatal s strain bacteria that had
been heat-killed, they did not die. however, if the heat-killed s strain bacteria were
mixed with harmless live r strain bacteria of the same species and injected, the mice did
die. surprisingly, living s strain bacteria were recovered from the bodies of the mice.
griffith concluded that some substance from the dead s strain bacteria passed to the r
strain bacteria, imparting virulence and the ability to form a capsule. avery and others
continued the search for the substance that “transformed” the r strain into the s strain.
hypothesis i: genetic material or “transforming substance” is protein.
hypothesis ii: genetic material or “transforming substance” is rna.
hypothesis iii: genetic material or “transforming substance” is dna.
an experiment was performed in which dnaase enzyme digestion prevented
transformation. this finding:
a. supports hypothesis i
b. supports hypothesis ii
c. supports hypothesis iii
d. rejects hypothesis i only.
e. rejects hypothesis ii only.
f. rejects hypothesis iii only.g. does not support any of these hypotheses.
4) active transport
a. requires an input of atp.
b. is involved in diffusion.
c. occurs in osmosis and facilitated transport.
d. all of the choices are correct.
5) removing the top of a plant to create fuller growth involves which of the following
hormones?
a. auxins
b. ethylene
c. gibberellins
d. cytokinins
6) in order to maximize diffusion across the surfaces of a gill, oxygen-rich water flows
in the opposite direction of oxygen-poor blood. this concept is called
a. reverse expiration.
b. pneumonectomy.
c. countercurrent flow.
d. partial pressure saturation.
e. hemoglobin saturation shift.
7) if you cut a herbaceous stem and observe fluids continually seeping upward and out
of the cut, it is most likely due to
a. root pressure.
b. turgor pressure.
c. active transport by phloem.
d. tension caused by transpiration.
e. cohesion to the xylem walls.
8) haiti is settled by peoples of both african and european ancestry. a young couple,
both with mixed ancestry, marry and have several children. the children vary widely in
the amount of skin melanin production, with one child being lighter than both parents,
and one being darker. the simple explanation for this is
a. epistasis.
b. multiple alleles are available for the one chromosomal locus that governs skin color.
c. the environment affected the phenotype that developed.
d. polygenic inheritance.
e. gene linkage.
9) the sequence of decreased death rate followed by a decrease in birthrate is called
a. environmental resistance.
b. a limiting factor.
c. doubling time coefficient.
d. demographic transition.
e. replacement reproduction.
10) homeostasis is the
a. negative feedback loop that stimulates a response similar to the stimulus.
b. dynamic interplay between events that tend to change the external environment and
events that tend to keep it the same.
c. the acquisition, transformation and use of energy.
d. maintenance of normal internal conditions by means of self-regulating mechanisms.
11) complete oxidative breakdown of glucose results in ______ atp molecules.
a. 2
b. 4
c. 32
d. 36
e. 39
12) determine the number of codon sequences it would require to produce the following
amino acid sequence: alanine – proline – serine – isoleucine – stop.
a. it would take 5 codon sequences.
b. it would take 3 codon sequences.
c. it would take 6 codon sequences.
d. it would take 4 codon sequences.
13) xeroderma pigmentosum
a. is characterized by a deficiency of rna repair enzymes.
b. is characterized by lung and colon cancers.
c. leaves the liver cells vulnerable to the mutagenic effects of uv light.
d. is associated with a high incidence of skin cancer.
incorrect
14) which of the following structures is a male reproductive structure?
a. archegonia
b. megaspore
c. pollen cone
d. pistil
15) a living organism represents stored energy in the form of chemical compounds.
when an organism dies, what happens to this stored energy?
a. all chemicals immediately lose their high-energy bonds.
b. all molecules immediately degrade into basic elements.
c. all energy immediately leaves, and that is one manifestation that the organism is
dead.
d. the chemical compounds in cells lose their organization over time because there is no
longer an input of energy to maintain the organized state.
e. the chemical compounds remain exactly intact and ready to start up again unless
digested by a consumer or decay organism.
16) the lymphoid organ in which b lymphocytes are produced is the
a. red bone marrow.
b. lymph nodes.
c. spleen.
d. thymus gland.
e. all of these produce b lymphocytes.
17) from your knowledge of the size and density of cell components and the process of
centrifugation, predict the order (from first to last) that the nucleus and various
cellorganelles will be extracted?
a. ribosomes-mitochondria and chloroplasts-nucleus-soluble cytoplasm
b. nucleus-mitochondria and chloroplasts-ribosomes-soluble cytoplasm
c. nucleus-mitochondria and chloroplasts-soluble cytoplasm-ribosomes
d. mitochondria and chloroplasts-nucleus-soluble cytoplasm-ribosomes
e. soluble cytoplasm-ribosomes-mitochondria and chloroplasts-nucleus
18) which of the following is a proximal cause that will stimulate birds to migrate?
a. environmental stimuli such as changes in temperature.
b. the bird getting older.
c. an increase in the number of males within the population causing an increase in
competition for mates.
d. a new predator moving into the environment that poses a threat to the survival of the
population.
e. all of these are proximal causes that will influence birds to migrate.