Bio Midterm 2

What was the surprising finding from Griffith's work with mice and pneumonia-causing bacteria in 1928?

• nonpathogenic cells (R cells) plus pathogenic S-cell mRNA caused pneumonia and killed mice.

• a heritable substance from heat killed pathogenic cells (S cells) transformed nonpathogenic (R cells) making them pathogenic and killed mice.

• nonpathogenic cells (R cells) plus pathogenic S-cell proteins caused pneumonia and killed mice.

• heat-killed pathogenic cells (S cells) caused pneumonia and killed mice.

In analyzing the number of different bases in a DNA sample, which result would be consistent with the base-pairing rules?

• A=C

• A+G=C+T

• A=G

• A+T=G+C

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

• The twisting nature of DNA creates nonparallel strands.

• One strand contains only purines and the other contains only pyrimidines.Base pairings create unequal spacing between the two DNA strnads.

• Base pairings create unequal spacing between the two DNA strnads.

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

Which of the following DNA sequences is complementary to 5' TAGAC 3'?

• 5' CAGAT 3'

• 5' ATCTG 3'

• 3' CAGAT 5'

• 5' GTCTA 3'

The copying of the information in DNA is efficient because

• The DNA molecule can be copied without disrupting the hydrogen bonds between bases

• Each strand of a DNA molecule carries complementary information and can be used as a template during replication

• Any purine (A or G) can pair with any pyrimidine (T or C).

   

• The pairing of two DNA strands allows DNA synthesis in both the 5' to 3' direction and the 3' to 5' direction

Which of the following unwinds the helix to provide a single-stranded template for DNA polymerase to be able to build a complementary strand?

• Topoisomerase

• DNase

• Helicase

• DNA binding proteins

Why is the lagging strand synthesized in a discontinuous fashion (multiple RNA primers and Okazaki fragments)?

• There isn’t any topoisomerase on the lagging strand

• The DNA polymerase enzyme that synthesizes the lagging strand can only synthesize short sequences of DNA before it falls off the template.

• DNA synthesis only occurs in a 5' to 3' direction, which causes lagging strand synthesis to “restart” as new 3’ regions of template DNA become available

• The lagging strand can’t be synthesized until the leading strand is completed

Which of the following best describes the function of telomerase at the telomere?

• It makes special primers that do not need to be removed.

• It adds new DNA to 3’ end of the new “daughter” strand (leading and lagging strand) of DNA

• It adds new DNA at the 3’ end of the template strand and the new “daughter” strand (leading and lagging strand) of DNA

• It adds new DNA to the 3’ end of the template strand of DNA

The process that produces mRNA from DNA is called

• translation.

• replication

• processing

• transcription

What process enables a single gene to encode two or more polypeptides that are different in their amino acid sequence?

• reverse transcription

• spliceosome processing

• alternative splicing

• capping