GENERAL BIOLOGY - FINAL EXAMINATION - FALL 1999

I_____________________________(your name) have not had any unsanctioned prior access to this examination and will conduct myself in an honest manner in regard to all aspects of this examination. Unless authorized by the course professor, I will not discuss the contents of this examination, in general or specific terms, until the examination is administered to all students.

REVIEW PORTION (150 PTS.)

PLEASE SELECT THE BEST ANSWER:

1) (3pts) Which of the following is in correct order (larger to smaller)

A) Kingdom, Phylum, Class, Species, Genus

B) Kingdom, Class, Order, Family, Genus

C) Phylum, Order, Class, Genus, Species

D) Kingdom, Phylum, Family, Order, Species

E) Kingdom, Phylum, Order, Genus, Family

2) (3pts) Which is not true of most prokaryotic cells:

A) They have cell walls.

B) They are smaller than most eukaryotic cells

C) They have DNA complexed with protein and organized into chromosomes.

D) They lack membrane-bound organelles

E) None of the above

3) (3pts) Most plant fats are liquid at room temperature because they are ____________ whereas those in animals are solid. (term employed to describe type of covalent bonding).

4) (3pts) Water is involved in:

A) Biological oxidations

B) Evaporative cooling

C) Condensation

D) Hydrolysis

E) All of the above

5) (3pts) Buffer systems work by:

A) Resisting changes in pH

B) Donating H ions to the solution when they are in excess

C) Removing H ions in the solution when they have been depleted

D) All of the above

E) None of the above

6) (3pts) Which of the following functional groups may be found on a sugar:

A) Hydroxyl

B) Carbonyl

C) Phosphate

D) Carboxyl

E) All of the above

7) (3pts) The structural level of a protein least affected by a disruption in hydrogen bonding is:

A) Primary level

B) Secondary level

C) Tertiary level

D) Quaternary level

8) (3pts) Noncompetitive inhibition:

A) May be reversed by adding more substrate

B) May not be reversed by adding more substrate

C) Demonstrates parallel slopes between inhibited and non-inhibited curves

on a Lineweaver-Burk plot

D) Occurs when an inhibitor attaches to the active site of the enzyme

9) (3pts) Enzymes:

A) Convert endergonic reactions into exergonic reactions

B) Lower the energy of the reaction

C) Lower the energy of activation

D) Alter the equilibrium of a reaction

E) Make reactions go that would not go without enzyme

10) (3pts) _______________________ is the name given the covalent bonds which hold nucleotides together to form polynucleotides.

11) (3pts) _______________________ is the name given the covalent bonds which hold monosaccharides together to form polysaccharides.

12) (3pts) _______________________ is the name given the bonds involved in stabilizing pleated sheets and a-helices.

13 & 14) A molecule of glucose is metabolized to CO₂ and H₂0 by an aerobic prokaryote:

13 (3pts) __________________(# of ATP) is the Net Gain in ATP

14 (3pts) __________________(# of ATP) is the number of ATP used in activation

15 & 16) (3pts each) Name the two trioses formed from the splitting of Fructose-1,6-diphosphate in Glycolysis: _____________________ & _________________________.

17) (3pts) Of these two trioses (questions 14 & 15), which is most directly metabolized to pyruvate? ______________________

18) (3pts) Which of the following organelles is common to plant and animal cells?

A) Wall made of cellulose

B) Tonoplast

C) Centriole

D) Ribosome

E) Mitochondria

19) (20pts) Fill in the following table with the symbols (+) or (-), depending whether or not you would anticipate the correct reaction occurring, i.e.(+) = a positive reaction should occur; (-) = a negative reaction should occur:

Substance	Benedict’s Reagent	Lugol’s Iodine	Ninhydrin Test	Biuret Test	Sudan IV
Proline
Albumin
Cream
Glucose

20) (12 pts) A cell contains 20 pg of DNA and 8 pair of homologous chromosomes when it is in G₂ of the cell cycle. Employ this information to fill in the following table:

	Metaphase	G1	Prophase	G0
pg DNA per cell
Total # of chromosomes per cell
# of chromatids per chromosome

21) (3pts) The light reactions of photosynthesis:

A) Are temperature insensitive under physiological conditions

B) Are photochemical reactions

C) Involve proton pumping

D) Involve electron transport chains

E) All of the above

F) None of the above

22) (3pts) P₇₀₀ is:

A) The reaction center for PS I

B) The reaction center for PS II

C) Involved in non-cyclic photophosphorylation only

D) The site photolysis of water

E) A special type of carotenoid; one bound to protein

23) (3pts) G-Protein receptor systems:

Are widespread

Evolved early

May involve many different signals

All of the above

None of the above

24) (3pts) Protein kinases:

Denature tertiary structure of proteins

Catalyze the formation of peptide bonds

Remove phosphates from proteins

Transfer phosphates from ATP to proteins

None of the above

25) (3pts) In function, the plant cell structure that is analogous to an animal cell’s cleavage furrow is the

A) chromosome

B) cell plate

C) nucleus

D) centrosome

E) spindle apparatus

26) (4pts) Crossing over can contribute to genetic variation by exchanging chromosomal segments between:

A. autosomal chromosomes and sex chromosomes

B. nonhomologous chromatids

C. nonsister chromatids of homologous chromosomes

D. sister chromatids

E. autosomal chromosomes and histones

27) (4pts) The Manx allele (M^L) in cats is a dominant allele that produces cats with an abnormal spine and no tail. The normal allele is M. Homozygous cats (M^LM^L) die as embryos. If two M^LM cats mate, among the surviving progeny, what is the probability that any one kitten will be homozygous?

28) (4pts) Red-green color blindness is caused by a sex-linked recessive allele. A color-blind man marries a woman with normal vision. Her father had normal vision, but her mother was colorblind. Assuming they have a daughter, what is the probability that they will have a colorblind daughter?

29) (4pts) Consider the lagging strand during DNA replication. After the RNA primer is replaced by DNA, which enzyme joins the Okazaki fragment to the growing strand by connecting the DNA backbone?

30) (6pts) Using the genetic code identify a possible 5´ to 3´ sequence of nucleotides in the DNA template strand for an mRNA coding for the amino acid sequence :: Leucine-Glycine-Glycine

A. GCCTCCTAA

B. TTAGGTGGC

C. UUAGGUGGC

D. AATCCTCCG

E. GAACCACCC

First Letter			Second Letter			Third Letter
	U	C		A	G
U	phenylalanine	serine		tyrosine	cysteine	U
	phenylalanine	serine		tyrosine	cysteine	C
	leucine	serine		STOP	STOP	A
	leucine	serine		STOP	tryptophan	G
C	leucine	proline		histidine	arginine	U
	leucine	proline		histidine	arginine	C
	leucine	proline		glutamine	arginine	A
	leucine	proline		glutamine	arginine	G
A	isoleucine	threonine		asparagine	serine	U
	isoleucine	threonine		asparagine	serine	C
	isoleucine	threonine		lysine	arginine	A
	methionine (START)	threonine		lysine	arginine	G
G	valine	alanine		aspartate	glycine	U
	valine	alanine		aspartate	glycine	C
	valine	alanine		glutamate	glycine	A
	valine	alanine		glutamate	glycine	G

31) (4pts) Which of the following DNA mutations results in the most change in the resulting amino acid sequence?

A. A single base deletion at the start of the coding sequence

B. A single base insertion in the middle of the first intron

C. A base-pair substitution in the middle of an exon

D. A base-pair substitution at the end of the coding sequence

E. A missense mutation in the middle of an exon

32) (4pts) In the lac operon, the inducer is __________. It inactivates the repressor, and is an isomer of ____________.

33) (4 pts) In eukaryotic retrotransposons, the enzyme encoded by the transposon itself is called:

A. Reverse transcriptase

B. transposase

C. retrotransposase

D. DNA ligase

E. RNA polymerase

34 (6pts) The following is a generalized signal transduction pathway:

A. Growth factor or B.. Membrane receptor C. G protein

Growth-inhibiting factor

D. Protein kinases E. Transcription Factor F. Protein that (phoshorylation cascade) either stimulates or inhibits the cell cycle

i. Identify the step at which a protein is defective (A-F) in the case of the Ras oncogene, where the cell cycle is overstimulated.

ii. Identify the step at which a protein is defective (A-F) in the case of the p53 protein, where the cell cycle is not inhibited.

New Material (150 points)

35) (12 pts) A couple who are planning to have children are concerned because both Pollyanna, the wife, and Wiseguy, the husband, have brothers who are hardcore cynics. Hardcore cynicism is a homozygous recessive (cc) genetic disease that manifests late in life and results in total disbelief that anything good ever happens. Heterozygotes (Cc) and homozygotes (CC) exhibit normal degrees of belief. The cynicism gene has been cloned, and the mutation causing the defect has been identified as a “grinch” insertion in the coding region that results in an addition of 100 bases. In turn, this results in an altered amino acid sequence and a non-functional protein.

________________________________________________normal allele

grinch insertion

____________________------------------_______________________________mutant allele

Chromosomal DNA was collected from cheek cell samples from Pollyanna and Wiseguy. DNA primers complementary to 20 bases on either side of the insertion region were made and used to amplify the region by polymerase chain reaction (PCR). The DNA amplified by PCR was then cut with the Sunshine II enzyme and analyzed by gel electrophoresis. A picture of the gel results is shown below:

a) Is Wiseguy a hardcore cynic, a carrier for the hardcore cynic disease, or neither?

b) if DNA from the affected brothers were tested in the same way, would the resulting PCR

product be (Choose one answer):

-one band at 200 base pairs

-one band at 300 base pairs

-two bands, one at 200 base pairs, one at 300 base pairs

c) What is the probability that Pollyanna and Wiseguy will have a hardcore cynic child?

d) What is the probability that they will have a child that is a carrier for the disease?

36. (9 pts) Select ALL the features below that apply to a cDNA (complementary DNA) library:

a) can be used to clone promoter or gene regulatory regions

b) can be used to clone coding regions of genes

c) is constructed from chromosomal DNA that has been cut by restriction enzymes

d) uses RNA as the source of genes for cloning

e) represents a collection of all the genes in an organism

f) could be used to clone genes expressed specifically in liver cells

37. (9 pts). Select ALL that apply. Once we determine the sequence of bases of a newly cloned gene, we can:

a) predict the amino acid sequence of the encoded protein

b) determine the position and number of restriction enzyme sites along the piece of cloned DNA

c) search sequence databases for similarities or homolgy to other known genes, which could provide clues to the function of the newly cloned gene

d) none of the above

38) (5pts) Do the following model organisms have longer or shorter generation times than the fly, Drosophila melanogaster?? (Also fill in any blanks)

i. The nematode      &nb