Deck 24: Genes,genomes and Chromosomes

Question 1

What term is used to describe a collection of cloned genomic fragments?

A)sequence
B)repository
C)fragmented genome
D)library
E)none of the above

Answer 1

D

Question 2

The argument that mitochondria and chloroplasts originally were self-sufficient bacteria is supported by the presence of what protein-DNA structure?

A)nucleoids
B)chromatin
C)importins
D)chromatids
E)nucleosomes

Answer 2

A

Question 3

What structure is responsible for linking the centromeres to the spindle fibers during mitosis?

A)metaphase plate
B)nucleosome
C)kinetochore
D)centromere scaffold
E)none of the above

Answer 3

C

Question 4

What technique is used to amplify portions of DNA,usually about 500 base pairs in size?

A)DNA sequencing
B)polymerase chain reaction
C)cloning
D)restriction digestion
E)electrophoresis

Question 5

A typical size for a viral genome is ______ nucleotides per haploid genome while a typical size for a bacterial genome is ______ nucleotides per haploid genome.

A)2 $\times$ 10⁶;4 $\times$ ⁸
B)8 $\times$ 10⁴;5 $\times$ 10⁷
C)1 $\times$ 10³;9 $\times$ 10⁴
D)5 $\times$ 10⁴;4 $\times$ 10⁶
E)3 $\times$ 10⁴;5 $\times$ 10⁹

Question 6

Which of the following describes a proper organization sequence for DNA in the nucleus?

A)DNA helix $\to$ nucleosome $\to$ chromatin fiber $\to$ condensed fiber
B)DNA helix $\to$ chromatin fiber $\to$ nucleosome $\to$ condensed fiber
C)DNA helix $\to$ condensed fiber $\to$ nucleosome $\to$ chromatin fiber
D)DNA helix $\to$ nucleosome $\to$ condensed fiber $\to$ chromatin fiber
E)none of the above

Question 7

Which of the following represents the correct order of steps usually taken in a Southern analysis?

A)electrophoresis $\to$ restriction digest $\to$ nitrocellulose transfer $\to$ hybridization
B)electrophoresis $\to$ hybridization $\to$ restriction digest $\to$ nitrocellulose transfer
C)hybridization $\to$ restriction digest $\to$ electrophoresis $\to$ nitrocellulose transfer
D)restriction digest $\to$ electrophoresis $\to$ hybridization $\to$ nitrocellulose transfer
E)restriction digest $\to$ electrophoresis $\to$ nitrocellulose transfer $\to$ hybridization

Question 8

The alteration in chromatin structure that occurs within the centromere is brought about by the replacement of which histone protein?

A)H1
B)H2A
C)H2B
D)H3
E)H4

Question 9

The combination of histone proteins with DNA gives rise to what structure?

A)cohesins
B)telomeres
C)centromeres
D)nuclear scaffold
E)nucleosomes

Question 10

A pseudogene is a ___________.

A)gene that codes for a non-functional protein
B)nonexpressed gene
C)mutated gene
D)gene with multiple promoter regions that causes the start of transcription to be mistaken
E)none of the above

Question 11

For a restriction enzyme with a 6-base recognition site,what is the average number of base pairs between occurrences of the site?

A)1296 base pairs
B)4096 base pairs
C)46656 base pairs
D)16777216 base pairs
E)none of the above

Question 12

BamHI has a restriction site of G $\downarrow$ GATCC while HpaI has a restriction site of GTT $\downarrow$ ACC.Based upon this,BamHI produces __________ and HpaI produces __________.

A)a 5' overhang;a 3' overhang
B)a 5' overhang;a 5' overhang
C)a 5' overhang;blunt ends
D)a 3' overhang;a 5' overhang
E)a 3' overhang;blunt ends

Question 13

Which histone protein is associated with the linker DNA and therefore not actually part of the nucleosome?

A)H1
B)H2A
C)H2B
D)H3
E)H4

Question 14

What chemical modification of host DNA is used to protect it against cleavage by the host's own restriction enzymes?

A)methylation
B)phosphorylation
C)acetylation
D)conversion of some cytosine to uracil
E)conversion of some guanosine to inosine

Question 15

Where in the following DNA sequence is the start of a 6-base type II restriction site? Every fifth nucleotide is indicated with a bold letter using the top strand for numbering.

A)1
B)7
C)10
D)18
E)there is no restriction site in this sequence

Question 16

What is a haplotype?

A)a collection of polymorphisms that occur by insertions
B)a collection of polymorphisms that occur by deletions
C)a collection of polymorphisms that occur by repetition of short sequences
D)a collection of polymorphisms that occur by single base changes
E)a collection of polymorphisms that display a distinct pattern that arises from the use of similar modifications to the area of the genome in question

Question 17

What does a yeast artificial chromosome (YAC)allow one to do?

A)selective analysis of yeast replication and transcription
B)incorporation of eukaryotic genes into prokaryotic cells
C)sequence analysis of DNA fragments up to 10⁶ base pairs in size
D)analysis of chromosomal-sized DNA in the absence of centromeres and telomeres
E)all of the above

Question 18

What is the term used to describe genetic variation that occurs among individuals of the same species resulting in gain or loss of restriction sites that can be detected by Southern analysis?

A)polymorphism
B)hybridization
C)clone
D)epigenetic variant
E)none of the above

Question 19

What is the typical percentage of lysine + arginine in histone proteins?

A)<5%
B)5-10%
C)10-20%
D)20-35%
E)>35%

Question 20

What is present in many eukaryotic genes that drastically increases the size of eukaryotic DNA,but are not present in prokaryotic genes?

A)satellite DNA
B)long interspersed elements
C)Alu sequences
D)exons
E)introns

Question 21

A linear DNA molecule was treated with PstI and gave two fragments with sizes of 2150 and 3420 base pairs.The same DNA was treated with BamHI and gave three fragments of 1250,1930 and 2390 base pairs.Finally,the DNA was treated with both enzymes at the same time and gave fragments of 900,1250,1490 and 1930 base pairs.Provide a map of the DNA molecule clearly indicating the restriction sites.

Question 22

Show the product of the following restriction digest.PstI has a restriction site of CTGCA $\downarrow$ G.P- indicate the 5' phosphate,-OH indicates the 3'hydroxyl.

Question 23

Southern analysis of an individual DNA sample with an overall size of 10.1 kbp using a restriction enzyme that recognized a 6-base restriction site gave the following results.If the same test was performed on a different individual and four bands were seen in the analysis,what would the result look like and why?

Question 24

What proteins,responsible for specific protein kinase activation,are major control elements in the cell cycle?

A)Rb proteins
B)cyclins
C)p53
D)cohesins
E)nonhistone chromosomal proteins