Question 1

What word below refers to a pair of homologous chromosomes?

Accepted Answer

A) chromophores 
B) bivalent 
C) birefringence 
D) bilateral 
E) nucleolus

Question 2

Which type of enzyme is essential for processes like DNA replication and transcription to prevent excessive supercoiling from developing as the complementary strands of the DNA duplex separate and unwind?

Accepted Answer

A) topoisomerase I 
B) topoisomerase II 
C) topologicase I 
D) topologicase II 
E) isomerase I

Question 3

When a gene is duplicated one or more times,it gives rise to a group of genes that may diverge by mutation,but their sequences will generally remain closely related and they will encode similar polypeptides.The proteins and genes produced in this way can be referred to as ________.

Accepted Answer

A) isotopes 
B) isomers 
C) isosceles 
D) gene families 
E) gene isoforms

Question 4

What kind of DNA sequence makes up from about 20% to more than 80% of the total DNA in a eukaryotic genome,depending on the organism,and includes sequences repeated within the genome a few times to tens of thousands of times?

Accepted Answer

A) moderately repeated DNA sequences 
B) nonrepeated sequences 
C) highly repeated sequences 
D) satellites,minisatellites and microsatellites 
E) very unique sequence DNA

Question 5

Hemoglobin molecules analyzed at various times during an animal's life seem to be highly variable.What is the explanation?

Accepted Answer

A) Contaminants at various points in an organism's life cause the variation in data. 
B) Hemoglobin denatures when isolated from older embryos. 
C) The combinations of of $\alpha$-family and $\beta$-family globin polypeptides differ with developmental stage. 
D) Hemoglobins are chemically altered as they age. 
E) Hemoglobins bind copper ions instead of iron ions.

Question 6

To what does avidin directly bind with high affinity?

Accepted Answer

A) RNA 
B) DNA 
C) fish 
D) biotin 
E) centromeres

Question 7

How is a cluster of tandemly repeated segments generated at a localized site within a chromosome?

Accepted Answer

A) by a single duplication event 
B) by multiple vaporizations 
C) by repeated duplication of a particular sequence over a number of generations 
D) by a single inversion event 
E) by a single deletion even

Question 8

What appears to be the reason for the production of the large Drosophila larvae salivary gland cells?

Accepted Answer

A) to allow less gene expression 
B) to allow moderate gene expression 
C) to allow cells to maintain their high secretory activity 
D) to allow the cells to take up more space 
E) to allow the cells to digest larger amounts of phagocytic material

Question 9

Satellite DNAs have been localized to what location during in situ hybridization studies?

Accepted Answer

A) nucleolus 
B) centromere 
C) spindle 
D) mitochondria 
E) nucleosomes

Question 10

The individual banding patterns on Drosophila chromosomes provided evidence for the validity of what phenomenon?

Accepted Answer

A) mitosis 
B) meiosis 
C) the ability to map the positions of genes on their chromosomes 
D) translation 
E) respiration

Question 11

You are studying three restriction enzyme sites.They are 4,6 and 8 bases long,respectively.Which one would probably be more plentiful in a given genome?

Accepted Answer

The answer of You are studying three restriction enzyme sites.They...

Question 12

You are given a sample of DNA and everything you need to carry out a renaturation study.The resulting data are composed of a single,symmetrical curve.What do you know about the curve and what can you guess about its source?

Accepted Answer

The answer of You are given a sample of DNA...

Question 13

What is one explanation for the wide discrepancies in genome sizes from species to species?

Accepted Answer

A) More advanced organisms have more DNA. 
B) Genomes have an extremely variable number of repeated DNA sequences that do not code for proteins. 
C) Some organisms have multiple repeats of each gene. 
D) More advanced organisms have more genes. 
E) More advanced organisms have more centromeric DNA.

Question 14

Which type of DNA sequence is typified by short sequences of DNA (five to a few hundred base pairs in length)repeated a large number of times in tandem to form very large clusters,each containing up to several million base pairs of DNA?

Accepted Answer

A) satellite DNAs 
B) minisatellite DNAs 
C) microsatellite DNAs 
D) consensus sequences 
E) microminisatellite DNAs

Question 15

_______ is thought to be derived from a reverse transcriptase encoded by an ancient retrotransposon.

Accepted Answer

A) Phosphatase 
B) Esterase 
C) Telomerase 
D) Protein kinase 
E) Phosphodiesterase

Question 16

What technique supplied the data that led Watson and Crick to the double helical structure of DNA?

Accepted Answer

A) sucrose density centrifugation 
B) polyacrylamide gel electrophoresis 
C) X-ray diffraction/crystallography 
D) autoradiography 
E) ion exchange chromatography

Question 17

Which of the following is an RNA nucleoside?

Accepted Answer

A) a phosphate group,adenine and ribose 
B) a phosphate group,guanine and deoxyribose 
C) cytosine and ribose 
D) thymine and deoxyribose 
E) a phosphate group and adenine

Question 18

________ plays a key role in replicating DNA at the ends of chromosomes.

Accepted Answer

A) PolyA polymerase 
B) DNA polymerase 
C) Telomerase 
D) Protein kinase 
E) Phosphodiesterase

Question 19

Which of the following is guanosine?

Accepted Answer

A) ribose + guanine 
B) guanine + deoxyribose 
C) guanine + thymine 
D) deoxyribose + guanine + phosphate group 
E) ribose + guanine + phosphate group

Question 20

The globin gene cluster contains stretches of DNA that are homologous to the sequences of functional globin genes,but contain severe accumulated mutations that render them nonfunctional.Most of these noncoding regions have no known function.They are considered to be evolutionary relics and are called _________.

Accepted Answer

A) reliquaries 
B) pseudoemissaries 
C) pseudogenes 
D) pseudoproteins 
E) pseudoglobins

Exam 10: The Nature of the Gene and the Genome