TEST 3

Question 1

Which of the following can cause a phenotypic change in an organism?
ALL OF THESE

Answer 1

Too few chromosomes.
Changes in part of a chromosome.
Too many chromosomes and too few chromosomes.
Too many chromosomes.

Question 2

Why are many polyploids sterile?

Answer 2

Extra sets of chromosomes segregate irregularly in meiosis leading to aneuploidic gametes.

Question 3

Which of the following disorders is not caused by a trisomy in human beings?

Answer 3

Turner’s syndrome

Down, Patau’s, Edwards - caused by trisomy

Question 4

Polyploids created from a hybridization between diff species are known as:

Answer 4

Allopolyploids

Question 5

Although most frequent forms of Down syndrome are caused by a random error, nondisjunction of chromosome 21, Down syndrome occasionally runs in families. The cause of this form of familial down syndrome is

Answer 5

a translocation between chromosome 21 and another chromosome

Question 6

What is the specific term that describes the loss of a single chromosome (2n-1)?

Answer 6

Monosomy

Question 7

The chromosomal aberration that cases cri-du-chat syndrome can be referred to as a

Answer 7

segmental deletion

Question 8

When mapping genes in bacteria, which of the following is true about the interrupted mating technique?

Answer 8

Genes are transferred from the donor to recipient in a linear fashion based upon time of contact.

Question 9

Bacteria that are in a particular physiological state to become transformed are called

Answer 9

component

Question 10

Bacteriophages engage in 2 interactive cycles with bacteria. What are these cycles?

Answer 10

Lytic and lysogenic

Question 11

When a bacteriophage genome incorporates itself into the chromosome of the host, that phage genome is referred to as a

Answer 11

prophage

Question 12

Whose experiments provided direct evidence indicating that DNA, rather than RNA or protein, is the genetic material in bacteriophages?

Answer 12

Hershey and Chase

Question 13

Which of the following is true regarding the structure of DNA?

Answer 13

Double stranded molecule and composed of nucleotides

Question 14

The central dogma specifies that the information in

Answer 14

DNA is copies into an RNA molecule during transcription, and the info in that RNA molecule is used to make a protein during translation

Question 15

The classic Hershey and Chase (1952) experiment that offered evidence in support of DNA being the genetic material in the bacteriophages made use of which of the following labeled components?

Answer 15

Phosphorus and sulfur

Question 16

The figure below shows a representative dinucleotide. The figure represents _____ and the arrow is closest to the _____ end.

Answer 16

DNA; 3’

Question 17

The basic structure of a nucleotide includes

Answer 17

base, sugar, phosphate

Question 18

What kind of daa on DNA structure was gathered by Rosalind Franklin and Maurice Wilkins?

Answer 18

X-ray diffraction pattern data

Question 19

DNA extracted from a cheek cell contains 16% cytosine. What percentage content of adenine would you find?

Answer 19

34

Question 20

What is meant by the description “antiparallel” regarding the strands that make up DNA?

Answer 20

The 5’ to 3’ direction of one strand runs counter to the 3’ to 5’ direction of the other strand.

Question 21

Explain the technique of electrophoretic separation of DNA fragments

Answer 21

A mixture of different sized DNA molecules are subjected to an electric field, and migrate through a semisolid matrix such that smaller fragments travel further in the matrix.

Question 22

What is the function of topoisomerase during the DNA replication process?

Answer 22

Relieving twisting tension in the DNA ahead of the replication fork.

Question 23

Which of the following enzymes catalyzes the synthesis of DNA during replication?

Answer 23

DNA polymerase

Question 24

Meselson and Stahl are best known for demonstrating that:

Answer 24

DNA replication occurs in a semi-conservative manner in E.coli

Question 25

The functions associated with telomeres are to:

Answer 25

facilitate replication of chromosomes without the loss of the chromosome’s arms tips

Question 26

When one DNA molecule is copied to make 2 DNA molecules, the new DNA contains

Answer 26

50% of the parent

Question 27

What is the basis for the difference in how the leading and lagging strands of DNA molecules are synthesized during DNA replication?

Answer 27

DNA polymerase can join new nucleotides only to the 3’ end of a growing strand.

Question 28

DNA replication occurs by adding

Answer 28

dNTPs to the 3’ end of the daughter strand

Question 29

The RNA molecule produced in RNA synthesis is:

Answer 29

complementary to the template DNA

Question 30

Which process transfers info from DNA to RNA?

Answer 30

transcription

Question 31

How many codons specify the different amino acids?

Answer 31

61

Question 32

Why is the reading fram of an mRNA important?

Answer 32

It is the series of nucleotide triplets that are read during translation.
If the reading frame is incorrect, the amino acid sequence will not be correct.

Question 33

Which of the following enzymes catalyzes DNA synthesis?

Answer 33

DNA polymerase