Bio 204 questions

During formation of eggs and sperm, one member of each chromosome pair is transmitted to each progeny cell in a type of cell division called Question 7 Answer a. meiosis b. cytokinesis c. gametogenesis d. mitosis

A

In Meselson and Stahl's experiment, cells were grown in media containing 15N in place of 14N, and then the cells' DNA was separated by equilibrium centrifugation. This experiment demonstrated that DNA Question 3 Answer a. replication is semiconservative b. replication is conservative c. forms double helices by means of hydrogen bonding between base pairs. d. replication requires DNA polymerase.

A

The DNA of eukaryotic cells is wrapped around histones to form structures called a.nucleoli. b.nuclear matrices. c.nucleosomes. d.centromeres

c

Purines

Adenine and Guanine (2 rings)

Topoisomerase

An enzyme that cuts DNA strands ahead of the replication fork and allows the DNA to rotate freely and unwind.

Our fundamental knowledge about mutation, genetic linkage, and the relationships between genes and chromosomes was acquired largely from experiments on the Question 6 Answer a. bacterium Pneumococcus. b. plant maize. c. fruit fly Drosophila. d. pea plant.

C

RNA in cells can serve as a Question 5 Answer a. carrier of information from the nucleus to the cytoplasm. b. catalyst or enzyme c. All of the above d. regulator of gene expression

C

What is the complementary sequence to the following bases? 5ʹ-TCAAGG-3ʹ Question 2 Answer a. 5ʹ-TCAAGG-3ʹ b. 5ʹ-AGUUCC-3ʹ c. 5ʹ-CCTTGA-3ʹ d. 5ʹ-AGTTCC-3ʹ

C

DNA replicates Question 4 Answer a. liberally b. conservatively c. by hybridization d. semiconservatively

D

Exonuclease

Removes RNA nucleotides from 5' end of Okazaki fragments and replaces them with deoxyribonucleotides

Eggs and sperm are :a. haploid. b. diploid. c. euploid. d. tetraploid.

a

Euchromatin consists of a.decondensed, transcriptionally active chromatin. b.100-nm chromatin fibers. c.DNA associated with nucleosomes. d.highly condensed, transcriptionally inactive chromatin.

a

Kinetochores are the Question 6Select one: a.sites of spindle fiber attachment to chromosomes. b.regions where two chromosomes remain attached during mitosis. c.same as centromeres. d.structures at the base of cilia and flagella.

a

Restriction endonucleases are enzymes that a.cleave DNA only at specific sequences. b.act only on the ends of DNA strands. c.act only in a single species of bacteria. d.cleave only nuclear DNA

a

The polymerase chain reaction is used to amplify specific fragments of DNA in vitro. a.True b.False

a

All known DNA polymerases synthesize DNA in the 5ʹ to 3ʹ direction. a. True b false

b

During mitosis, highly condensed chromosomes consist of two sister chromatids joined at the Question 7Select one: a.centrosome .b.centromere. c.kinetochore. d.spindle fiber

b

Heterochromatin gets its name from the fact that it contains a mixture of active and inactive genes. a. True b. False

b

In eukaryotic cells, RNA primers are removed by the combined action of 5ʹ to 3ʹ exonucleases and a. RNase A. b. RNase H. c. DNA polymerase I. d. DNA polymerase α.

b

In polysaccharides, sugars are linked together by means of _______ bonds. Question 8Answera. hydrophobic b. glycosidic c. peptide d. phosphodiester

b

Origins of replication are the a. sites where DNA transcription starts. b. binding sites for the protein complex that initiates DNA synthesis c. loops with two replication forks seen in replicating DNA. d. forks where DNA replication is occurring.

b

Sugars can cyclize if they contain _______ or more carbons Question 9Answera. four b. five c. six d. seven

b

In E. coli, the major enzyme responsible for DNA replication is DNA polymerase Question 2Select one:a. I. b. II. c. III. d. a

c

Nucleic acid hybridization is the :a.mating of two genetically different organisms. b.formation of hybrid nuclei when two cells are fused . c.formation of a double-stranded molecule from the interaction of two complementary-sequence single-stranded molecules. d.recombining of DNA molecules from two different organisms.

c

Telomeres are a.microtubule binding sites in the center of chromosomes. b.sites at the ends of chromosomes where DNA replication begins. c.chromosome end structures required for complete replication of linear chromosomes. d.sites at the ends of chromosomes where microtubules bind.

c

Pyrimidines

cytosine, thymine, uracil

DNA polymerases can synthesize DNA a. de novo by catalyzing the polymerization of free dNTPs. b. by adding dNTPs to complementary dNTPs on a single-stranded DNA. c. by adding dNTPs to a hydroxyl group on the end of a growing polynucleotide chain hydrogen-bonded to a strand of RNA. d. by adding dNTPs to a hydroxyl group on the end of a growing polynucleotide chain hydrogen-bonded to a strand of DNA.

d

Homology-directed repair a. is used to repair double-stranded breaks b. has much greater accuracy compared to non-homologous end-joining c. mediated recombination of homologous chromosomes during meiosis d. all of the above

d

The chromosomes of prokaryotes differ from those of eukaryotes in that prokaryotic chromosomes are Question 1Select one: a.linear .b.multiple .c.complexed with histones .d.circular.

d

When thymidine and adenosine interact within a DNA molecule, they form Question 10Answera. nucleotide triphosphates b. two phosphodiester bonds c. three hydrogen bonds d. two hydrogen bonds

d

Animal cells and most cells of higher plants are a. tetraploid b. euploid c. haploid d. diploid

diploid

The technique by which fragments of DNA are separated by gel electrophoresis, denatured, blotted on nitrocellulose paper, labeled with a complementary radioactive probe, and detected by autoradiography is called _______ blotting.

southern

Hydrogen bonds

strongest IMF(but weaker than covalent bonds), that forms between two adjacent nucleotides. G and C have 3 hydrogen bonds. A and T have 2 hydrogen bonds.