BIO100TEST#1

B

Cell walls: A. only occur in plant cells. B. are not completely solid, having many small pores. C. confer less structural support than the plasma membrane. D. dissolve when a plant dies. E. are made primarily from phospholipids.

D

Cellular fingerprints: A. are exposed on the cytoplasmic side of the membrane. B. are made from phospholipids. C. are "erased" by the HIV virus. D. can help the immune system distinguish "self" from "non-self". E. All of the above are correct.

D

DNA is a macromolecule that stores information. Which component of DNA is the source of this information? A. the histone B. the sugar C. the phosphate group D. the base E. the ladder

D

Highly repetitive sequences of DNA: A. are characteristic of protein-coding genes. B. are used in genetic engineering to create recombinant DNA. C. are binding sites for transcription factors. D. can be used to produce a DNA fingerprint. E. act as promoters for genes.

E

If your hypothesis is rejected, then: A. you should change the level of statistical significance until your hypothesis is accepted. B. your experiment was a success. C. your experiment was a failure. D. your experiment was poorly designed. E. you may still have learned something important about the system you were testing.

C

In humans, genes make up ______ of the DNA. A. about 75% B. 100% C. less than 5% D. about 10% E. about 50%

D

In order for a person's DNA to be used for his or her identification, which of the following tools/techniques must also be used in the process? A. PCR B. gel electrophoresis C. recombinant DNA D. Both a) and b) must be used. E. Both b) and c) must be used.

D

To start the transcription process, a large molecule, ______, recognizes a ______. A. RNA polymerase; messenger RNA B. DNA polymerase; termination site C. DNA polymerase; promoter site D. RNA polymerase; promoter site E. DNA polymerase; messenger RNA

D

What is the function of mitochondria? A. to make proteins and carbohydrates B. to control the genetic activities of the cell C. to repair the ribosomal subunits D. to harvest energy from food molecules

D

Which cellular structure makes it possible for a cell to differ structurally and biochemically from its surroundings? A. endoplasmic reticulum B. nucleus C. cell wall D. plasma membrane E. nucleolus

E

Which of the following are always the same in every DNA nucleotide? A. the sugar B. the base C. the phosphate group D. Only a) and b) are always the same. E. Only a) and c) are always the same.

C

Which of the following is found in both prokaryotic and eukaryotic cells? A. nucleus B. Golgi apparatus C. ribosome D. mitochondria E. lysosome

E

Which of the following is the BEST description of a control group in an experiment A) the control group is a test group that is chosen at random B) The control group and the test groups may have several differences between them C) There can be more than one difference between the control group and test groups, but not several differences or else the experiment is invalid D) there should be more than one control group in any experiment E) the control group is identical to each test group except for one variable

D

Which of the following is the primary site of protein assembly within eukaryotic cells? A. the smooth endoplasmic reticulum B. the nucleus C. the Golgi apparatus D. the ribosomes E. the vesicles

D

Which of the following issues would be least helped by application of the scientific method? A. developing more effective high school curricula B. evaluating the relationship between violence in videogames and criminal behavior in teens C. determining the most effective safety products for automobiles D. formulating public policy on euthanasia E. comparing the effectiveness of two potential antibiotics

B

Which of the following organelles is responsible for degrading waste within the cell? A. ribosome B. lysosome C. Golgi apparatus D. chloroplast E. endoplasmic reticulum

E

Which of the following statements about the cell theory is correct? A. All living organisms are made up of one or more cells. B. All cells arise from other, pre-existing cells C. All eukaryotic cells contain symbiotic prokaryotes. D. All prokaryotic cells contain symbiotic eukaryotes. E. Both a) and b) are correct.

A

You note a fuzzy growth on some of the gels in your incubator. What is the name given to this step of the scientific method? A. observation B. hypothesis C. theory D. law E. confirmation

A

"Engaging in aerobic activity three times each week will reduce cholesterol levels" is a: A. testable hypothesis. B. control group. C. scientific control. D. critical experiment. E. All of the above are correct.

B

------ are found in all metabolically active cells and are involved primarily in transporting materials within, into, and out of cells. A) vacuoles B) vesicles C) peroxisomes D) ribosomes E) lysosomes

A

An experimental condition applied to research subjects is called a: A. treatment. B. randomization. C. placebo. D. variable. E. control.

C

According to the theory of endosymbiosis, the origin of chloroplasts probably involved: A. the formation of cell walls around the photosynthetic pigments. B. the formation of colonies of cyanobacteria. C. the engulfing of small photosynthetic prokaryotes by larger cells. D. the accumulation of free oxygen in ocean waters. E. All of the above are correct.

E

After amplifying a region of chromosome 5 with a short tandem repeat sequence using PCR (polymerase chain reaction), you pour your DNA sample into a gel to see the results of the reaction. Two bands are present on the gel. The best explanation is: A. The DNA was contaminated. B. The DNA sample was degraded. C. The DNA sample was exposed to restriction enzymes. D. The PCR reaction also amplified a region on chromosome 3. E. Two alleles were present that vary in the number of repeats.

C

After generating a hypothesis, a scientist next: A. writes a grant proposal. B. formulates a theory. C. makes a prediction. D. does an experiment. E. designs a series of tests.

D

Bacteria use restriction enzymes to: A. breakdown protein. B. synthesize RNA. C. synthesize DNA. D. cut foreign DNA into fragments. E. synthesize protein.

B

Biology is ________. A. mostly a collection of facts that can be ordered and memorized B. the study of living things C. a separate branch of science from the study of how organisms interact with each other and with their environment D. always used responsibly in advertising claims E. Both a) and b) are true.

E

To absorb large particles, cells engulf them within their plasma membrane in a process called: A. transcription. B. translation. C. exocytosis. D. replication. E. endocytosis.

C

Deletions and substitutions are two types of point mutations. Which type is more likely to cause mistranslations of proteins? A. Substitutions, because they shift the reading frame and cause downstream amino acids to be changed. B. Substitutions, because one protein is substituted for another protein. C. Deletions, because they shift the reading frame and cause downstream amino acids to be changed. D. Deletions, because one protein is deleted. E. None of the above is correct.

D

During eukaryotic translation, ______ carries genetic information from the nucleus to the ribosome, where amino acids are assembled into proteins. A. tRNA B. RNA polymerase C. vesicles D. mRNA E. rRNA

A

During the polymerase chain reaction (PCR), two strands of DNA are separated by: A. exposure to heat. B. centrifugation. C. exposure to low pH. D. gel electrophoresis. E. exposure to denaturing enzymes.

E

During transcription, at the point where the DNA strand being copied has an A (adenine), a(n) ______ is added to the ______. A. T (thymine); tRNA B. C (cytosine); DNA C. G (guanine); tRNA D. A (adenine); mRNA E. U (uracil); mRNA

D

Thinking scientifically relies on which of the following? A) statements from authorities B) learning a list of facts C) intuition D) objective observation and experimentation E) applying your preconceptions

B

In plant cells, chloroplasts: A. serve the same purpose that mitochondria serve in animal cells. B. are the site of conversion of light energy into chemical energy. C. play an important role in the breakdown of plant toxins. D. have their own linear strands of DNA. E. Both a) and b) are correct.

E

In the regulation of gene expression, a protein that increases the binding of RNA polymerase to a gene's promoter region is a(n) _____. This is an example of ____. A. repressor; negative control B. activator; negative control C. transcription factor; epigenetics D. operator; positive control E. activator; positive control

D

In which organelle are lipids synthesized and modified within the eukaryotic cell? A. the Golgi apparatus B. the rough endoplasmic reticulum C. the lysosome D. the smooth endoplasmic reticulum E. the vesicle

C

Membrane-bound vesicles containing a substance synthesized by a cell fuse to the outer cell membrane and release their contents to the outside world. What is this process called? A. excretocytosis B. pinocytosis C. exocytosis D. phagocytosis E. endocytosis

B

Most genes come in alternative forms called: A. gametes. B. alleles. C. dominants. D. recessives. E. chromosomes.

D

Scientific theories do not represent speculations or guesses about the natural world. Rather they are hypotheses—proposed explanations for natural phenomena—that have been: A. verified by at least one critical experiment. B. found to be statistically significant. C. validated by the International Board of Scientific Theories. D. so strongly and persuasively supported by empirical observation that the scientific community views them as unlikely to be altered by new evidence. E. used to support the political stances of the scientists that have developed them.

B

Statistical methods make it possible to: A. prove any hypothesis is true. B. determine how likely it is that certain results have occurred by chance. C. unambiguously learn the truth. D. reject any hypothesis. E. test non-falsifiable hypotheses.

C

The combination of DNA from two or more sources is called: A. 2-DNA. B. human growth hormone. C. recombinant DNA. D. biotechnology. E. RNA.

D

The complementary base pairs in a DNA molecule are stabilized by: A. the electrostatic interactions of the charged backbone. B. a covalent bond. C. a salt bridge. D. hydrogen bonds. E. Both a) and b) are correct.

D

The cytoskeleton: A. is a viscous fluid found in all cells. B. fills a cell's nucleus but not the other organelles. C. gives an animal cell shape and support, but cannot control movement. D. helps to coordinate intracellular movement of organelles and molecules. E. All of the above are correct.

D

The expression of a gene to form a polypeptide occurs in two major steps. What are these two steps in their correct chronological order? A. transcription and then replication B. replication and then translation C. replication and then transcription D. transcription and then translation E. translation and then transcription

B

The full set of an individual organism's DNA is called its: A. complement. B. genome. C. nucleosome. D. nucleotide. E. chromosome.

A

The polymerase chain reaction (PCR): A. makes it possible to create huge numbers of copies of tiny pieces of DNA. B. enables researchers to determine the sequence of a complementary strand of DNA when they have only single-stranded DNA. C. utilizes RNA polymerase to build strands of DNA. D. can create messenger RNA molecules from small pieces of DNA. E. All of the above are correct.

D

The three codons that do not code for any amino acid—UAA, UAG, and UGA—are known as: A. repressors. B. termination sequences. C. promoters. D. stop codons. E. start codons.

B

There are different ______ molecules for each of the 20 different amino acids that are used in building proteins. A. ribosomal subunit B. tRNA C. mRNA D. DNA E. elongation