Unit 4 (Part I)

Question 1

Gregor Mendel discovered the principles of genetics in his early experiments on…

Answer 1

peas

Question 2

During formation of eggs and sperm, one member of each chromosome pair is transmitted to each cell in a type of cell division called…

Answer 2

meiosis

Question 3

Most animal cells are…

Answer 3

diploid

Question 4

Eggs and sperm are…

Answer 4

haploid

Question 5

The acceptance of the chromosome theory of inheritance followed the mapping of nearly a hundred genes on the four chromosomes of the…

Answer 5

fruit fly Drosophila

Question 6

George Beadle and Edward Tatum provided evidence for the one gene-one enzyme hypothesis in their experiments on the…

Answer 6

fungus Neurospora

Question 7

DNA was identified as the genetic material in experiments done by…

Answer 7

Avery, Macleod, and McCarty

Question 8

Deduction of the structure of DNA was based on X-ray crystallographic studies done by…

Answer 8

Wilkins and Franklin

Question 9

DNA is a double helix with … base pairs per complete turn of the helix.

Answer 9

10

Question 10

In the base pairing within a DNA double helix, …

Answer 10

A pairs with T and G pairs with C

Question 11

DNA replicates…

Answer 11

semiconservatively

Question 12

When thymidine and adenosine interact within the DNA molecule, they form…

Answer 12

two hydrogen bonds.

Question 13

In the Meselson and Stahl’s experiment, cells were grown in media containing 15N in place of 14N, and then their DNA was separated by equilibrium centrifugation. This experiment demonstrated that DNA…

Answer 13

replication is semiconservative.

Question 14

RNA molecules that serve as templates for protein synthesis are called… RNAs.

Answer 14

messenger

Question 15

How many different amino acids does the genetic code encode?

Answer 15

20

Question 16

Which of the following deletions will not change the reading frame of a gene?

Answer 16

Three nucleotides

Question 17

A codon is a…

Answer 17

Sequence of three nucleotides on an mRNA that binds to specific tRNAs.

Question 18

Because the genetic code usually has more than one codon for each amino acid, the code is said to be…

Answer 18

degenerate.

Question 19

How many different RNA triplets specify amino acids?

Answer 19

61

Question 20

Reverse transcriptase is an enzyme that catalyses… synthesis.

Answer 20

RNA-directed DNA

Question 21

Restriction endonuclease are enzymes that…

Answer 21

cleaves DNA only at specific sequences.

Question 22

To cut eukaryotic chromosomal DNA into large pieces of about 100 kilo bases, one would use a restriction nuclease that recognises and cuts in the middle of sequences that are … pairs long.

Answer 22

8 base

Question 23

The first enzymatic step in making a cDNA uses which of the following?

Answer 23

Reverse transcriptase

Question 24

To clone genes, a plasmid vector should contain a(n)…

Answer 24

All of the above (answer)

*Origin of replication;
restriction nuclease cut site;
antibiotic resistance gene;
both a and c

Question 25

Which of the following would be used to express a human protein in E.coli?

Answer 25

An expression plasmid containing cDNA made from the mRNA for the protein.

Question 26

Which of the following would be used to clone intact pieces of human DNA that are 400 kb pairs long?

Answer 26

Yeast artificial chromosomes

Question 27

A bacterial artificial chromosome is a vector...

Answer 27

derived from a plasmid with an origin of replication.

Question 28

the most common method of DNA sequencing is based on premature termination of DNA synthesis by inclusion of...

Answer 28

dideoxynucleotides

Question 29

Vectors for expressing a eukaryotic protein in a bacterium must contain which of the following?

Answer 29

All of the above (answer) *Bacterial promoter; Bacterial ribosome-binding sequence; Origin of replication; Both a and c.

Question 30

Expression of a human protein in a bacterial cell is best done with human...

Answer 30

cDNA in a bacterial expression vector.

Question 31

Taq polymerase is used in the polymerase chain reaction because it...

Answer 31

is stable at high temperatures.

Question 32

Nucleic acid hybridisation is the...

Answer 32

formation of a double-stranded molecule from the interaction of two complementary-sequence single-stranded molecules.

Question 33

Heat-denatured DNA will renature when cooled to about...

Answer 33

65C

Question 34

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.

Answer 34

Southern.

Question 35

The... technique would be used to compare expression of 10,000 genes in two different conditions (e.g. normal cells are cancer cells).

Answer 35

DNA microarray

Question 36

The technique by which a particular nucleic acid sequence is localised with labeled probes in a cell, tissue, or isolated chromosomes is called... hybridisation.

Answer 36

in situ

Question 37

To identify, in a sample, the protein against which you have an antibody, the best technique to used would be ... blotting.

Answer 37

Western

Question 38

SDS-polyacrylamide gel electrophoresis (SDS-PAGE) separates proteins on the basis of which of the following?

Answer 38

Size

Question 39

Temperature-sensitive mutants of yeast are useful because they...

Answer 39

allows identification of genes that control processes such as cell cycle progression, which are blocked when the gene product (protein) does not function at the non permissive temperature.

Question 40

The experimental introduction of DNA into eukaryotic cells is called...

Answer 40

Transfection.

Question 41

DNA can be introduced into cells by...

Answer 41

All of the above (answer) *Microinjection into the nucleus of a cell; fusion of DNA-containing liposomes with cells; electroporation of DNA into cells; Both a and b.

Question 42

Transgenic mice are usually produced by...

Answer 42

injecting DNA containing the gene into the pronucleus of a fertilised egg.

Question 43

Transgenic plants are easier to produce than transgenic animals because...

Answer 43

Plants can be grown from single cultured cells into which recombinant DNA has been introduced.

Question 44

Mutations are introduced into selected genes of living cells by...

Answer 44

homologous recombination with an altered cloned gene.

Question 45

When introduced into living cells, RNAi molecules bind...

Answer 45

proteins called RISC and cleave the complementary mRNA.

Question 46

in RNA interference, expression of a gene is most effectively inhibited by injection of...

Answer 46

double-stranded RNA

Question 47

A dominant inhibitory mutant is typically one that...

Answer 47

produces a protein that interferes with the function of the protein produced by the normal gene.