Exam 3

Exam #3: General Biology May 2004

Multiple Choice

Identify the letter of the choice that best completes the statement or answers the question.

____ 1. A karyotype

a.	compares one set of chromosomes to another.
b.	is a visual display of chromosomes arranged according to size.
c.	is a photograph of cells undergoing mitosis during anaphase.
d.	of a normal human cell shows 48 chromosomes.
e.	cannot be used to identify individual chromosomes beyond the fact that two chromosomes are homologues.

____ 2. The DNA molecule could be compared to a

a.	hairpin.
b.	ladder.
c.	key.
d.	globular mass.
e.	flat plate.

____ 3. Sex chromosomes

a.	determine sex.
b.	vary from one sex to another.
c.	carry some genes that have nothing to do with sex.
d.	were unknown to Mendel.
e.	all of these

____ 4. Ribosomes function as

a.	a single unit.
b.	two-part units.
c.	three-part units.
d.	four-part units.
e.	a multidivisional unit.

____ 5. Preimplantation diagnosis

a.	usually requires abortion.
b.	relies on in-vitro fertilization.
c.	is a form of amniocentesis.
d.	is a phenotypic treatment.
e.	occurs about midway through a pregnancy.

____ 6. Transcription

a.	occurs on the surface of the ribosome.
b.	is the final process in the assembly of a protein.
c.	occurs during the synthesis of any type of RNA from a DNA template.
d.	is catalyzed by DNA polymerase.
e.	all of these

____ 7. Cancer cells

a.	have altered plasma membranes.
b.	are unable to attach to other cells.
c.	divide to produce high densities of cells.
d.	have a different metabolism, using glycolysis even when oxygen is available.
e.	all of these

____ 8. The nitrogenous base found in DNA but not in RNA is

a.	adenine.
b.	cytosine.
c.	guanine.
d.	uracil.
e.	thymine.

____ 9. A gene mutation

a.	is a change in the nucleotide sequence of DNA.
b.	may be caused by environmental agents.
c.	may arise spontaneously.
d.	can occur in all organisms.
e.	all of these

____ 10. The DNA molecule is usually made up of how many strands?

a.	1
b.	2
c.	3
d.	6
e.	12

____ 11. DNA polymerase

a.	is an enzyme.
b.	adds new nucleotides to a strand.
c.	proofreads DNA strands to see that they are correct.
d.	derives energy from ATP for synthesis of DNA strands.
e.	all of these

____ 12. Amino acids are joined together in proteins by

a.	hydrogen bonds.
b.	peptide bonds.
c.	anticodons.
d.	wobble effects.
e.	codon bonds.

____ 13. In the bonding of nitrogenous bases

a.	adenine is paired with cytosine.
b.	adenine is paired with guanine.
c.	cytosine is paired with thymine.
d.	guanine is paired with cytosine.

____ 14. A chromosome that has been broken and rejoined in a reversal sequence has undergone

a.	inversion.
b.	deletion.
c.	duplication.
d.	translocation.
e.	crossing over.

____ 15. James Watson and Francis Crick

a.	established the double-stranded nature of DNA.
b.	established the principle of base pairing.
c.	explained how DNA's structure permitted it to be replicated.
d.	proposed the concept of the double-helix.
e.	all of these

____ 16. Mutations can be

a.	random.
b.	beneficial.
c.	harmful.
d.	heritable.
e.	all of these

____ 17. Uracil will pair with

a.	ribose.
b.	adenine.
c.	cytosine.
d.	thymine.
e.	guanine.

____ 18. Each "word" in the mRNA language consists of how many letters?

a.	three
b.	four
c.	five
d.	more than five
e.	none of these

____ 19. The location of a gene on a chromosome is its

a.	centromere.
b.	locus.
c.	autosome.
d.	allele.
e.	none of these

____ 20. The spread of a cancer from one site to others in the body is known as

a.	benign tumor.
b.	metastasis.
c.	malignant tumor.
d.	remission.
e.	both benign tumor and malignant tumor.

____ 21. The specific name given to a cancer-producing chemical is

a.	pathogen.
b.	carcinogen.
c.	teratogen.
d.	mutagen.
e.	oncogene.

____ 22. Bacteriophages are

a.	large bacteria.
b.	pathogens (disease-producing bacteria).
c.	viruses.
d.	cellular components.
e.	protistans.

____ 23. Chromosomes other than those involved in sex determination are known as

a.	nucleosomes.
b.	heterosomes.
c.	alleles.
d.	autosomes.
e.	liposomes.

____ 24. Replication of DNA

a.	produces RNA molecules.
b.	produces only new DNA.
c.	produces two molecules, each of which is half-new and half-old DNA joined lengthwise to each other.
d.	generates excessive DNA, which eventually causes the nucleus to divide.
e.	is too complex to characterize.

____ 25. Which of the following designates a normal human female?

a.	XXY
b.	XY
c.	XX
d.	XYY
e.	XO

____ 26. In the pairing of two nucleotides within the double helix

a.	hydrogen bonds are used.
b.	adenine and thymine bind together.
c.	purines bind with pyrimidines.
d.	double-ring nitrogenous bases connect to single-ring bases.
e.	all of these

____ 27. The difference between normal hemoglobin and sickle-cell hemoglobin is in the

a.	heme portion of the molecules.
b.	number of chains of amino acids.
c.	substitution of a specific amino acid for another specific amino acid.
d.	addition of one amino acid to the normal hemoglobin molecule.
e.	loss of only one amino acid from the normal hemoglobin molecule.

____ 28. The most recent technique for analyzing the genetics of the unborn child involves the sampling of

a.	the fetus directly.
b.	cells in the amniotic fluid.
c.	material from the allantois.
d.	the chorionic villi.
e.	yolk sac material.

____ 29. When cells are not responding to normal controls over growth and division, they form a tissue mass known as a

a.	metastasis.
b.	malignancy.
c.	tumor.
d.	carcinogen.
e.	puff.

____ 30. Karyotyping is usually done using what kind of cells?

a.	muscle
b.	blood
c.	cartilage
d.	sex
e.	epidermal

____ 31. Rosalind Franklin's research contribution was essential in

a.	establishing the double-stranded nature of DNA.
b.	establishing the principle of base pairing.
c.	establishing most of the principal structural features of DNA.
d.	sequencing DNA molecules.
e.	determining the bonding energy of DNA molecules.

____ 32. DNA coding regions that affect the same trait are called

a.	homologues.
b.	alleles.
c.	autosomes.
d.	loci.
e.	gametes.

____ 33. Who discovered the process of meiosis?

a.	Morgan
b.	Mendel
c.	Sturtevant
d.	Weismann
e.	Flemming

____ 34. Queen Victoria

a.	was a carrier of hemophilia.
b.	had a hemophilic parent.
c.	had hemophilia.
d.	married a man with hemophilia.
e.	both had a hemophilic parent and married a man with hemophilia.

____ 35. Routine treatments for genetic disorders currently involve

a.	substituting normal for defective parents.
b.	substituting normal for defective genes.
c.	supplying a missing gene.
d.	supplying missing enzymes or gene products.
e.	all of these

____ 36. Which of the following designates a normal human male?

a.	YY
b.	XX
c.	XY
d.	XO
e.	XYY

____ 37. In Down syndrome

a.	as the age of the mother increases, the chance of the defect occurring in the unborn children increases.
b.	the father has very little influence on the defect.
c.	most embryos abort before complete term.
d.	a person with the defect cannot have a normal child.
e.	none of these

____ 38. Which of the following would be the least satisfactory organism for genetic research?

a.	humans
b.	bacteria
c.	corn
d.	fruit flies
e.	peas

____ 39. A hormone would most likely act as a(n) __________ in a cell.

a.	repressor
b.	inhibitor
c.	activator
d.	promoter
e.	operator

____ 40. Amniocentesis involves sampling

a.	the fetus directly.
b.	the fetal cells floating in the amniotic fluid.
c.	sperm.
d.	blood cells.
e.	placental cells.

____ 41. A chromosome's gene sequence that was ABCDEFG before modification and ABCDLMNOP afterward is an example of

a.	inversion.
b.	deletion.
c.	duplication.
d.	translocation.
e.	crossing over.

Exam #3: General Biology May 2004

Answer Section

MULTIPLE CHOICE

1. B

2. B

3. E

4. B

5. B

6. C

7. E

8. E

9. E

10. B

11. E

12. B

13. D

14. A

15. E

16. E

17. B

18. A

19. B

20. B

21. B

22. C

23. D

24. C

25. C

26. E

27. C

28. D

29. C

30. B

31. C

32. B

33. D

34. A

35. D

36. C

37. A

38. A

39. C

40. B

41. D