Biol 1350 Midterm Exam Questions With
Correct Answers
Categorize different forms of biological information (1.1) - ANSWER heritable
information provides continuity of life. non-heritable info is transmitted w/in and
b/w biological systems. information is shared knowledge (communication or
reception of knowledge); signal representing data that justifies a change
Interpret data showing that DNA is the heritable material and protein is not. (1.2
+ 1.3) - ANSWER Griffith demonstrated that the "S factor" produced more S cells
and its info was being communicated from parent to offspring. Avery extracted
water-soluble material to convert r cells -> S cells. Only DNase eliminated the
ability to transform the R cells -> S cells. Hershey + Chase blender experiment:
infer that sulfur-containing protein has no function in phage multiplication and
that DNA has some function.
Evaluate experimental design and analyze data from research on DNA as
molecular information. (1.2 + 1.3) - ANSWER Griffith's mice experiment. and then
his experiment with the cytoplasm and the cell membrane to figure out if it's DNA
or protein. membrane worked but not when washed with a buffer.
Avery's robust protocol, centrifuge, and using proteases, RNase, and DNase.
compared N/P ratio .
Hershey + Chase blender experiment with isotopes of radioactive p (in DNA) and
s (in protein). centrifuge. 80% protein not in cell and 70% dna in cells
explain the differences between S and R Streptococcus pneumoniae - ANSWER
injecting bacteria from R (rough) colonies into mice did not kill them, but
injecting bacterial S (smooth) colonies did
Compare and contrast the building blocks of DNA and proteins - ANSWER that
proteins are composed of twenty different amino acids, whereas DNA and RNA
are composed of only four different nucleotides. DNA has nitrogen and
phosphorus, proteins don't have phosphorus.
explain why amino acids make a better code than nucleotides and why biologists
were reluctant to concede that DNA was the heritable material. - ANSWER This
numerical difference (4 DNA nucleotides versus 20 amino acids) convinced the
biologists of Griffith's generation that protein was a logical choice for the
genetic code. Proteins studied more.
recognize the structure of DNA, including the nucleotides, double helix and base
pairings - ANSWER DNA composed of CHONP, nucleotides (phosphate group,
, nitrogenous base, and a 5-carbon sugar). second carbon lacks an O. A w/ T (2 h-
bonds), C w/ G (3 bonds). a and g have two rings(purines) and C and T are
pyrimidines. double helix helps with replication. Watson, crick, Wilkins, stokes,
Wilson, Franklin and gosling. 2 strands antiparallel 5' to 3'
demonstrate how DNA replication is semi-conservative - ANSWER meselson +
stahl use stable isotopes of N. 2 bands. lighter gets darker.
estimate the amount of DNA in a sample by finding the area under a curve -
ANSWER find area under graph using triangles and convert to percentages.
determine the number of generations that have passed in a population of cells -
ANSWER formula:
log_2 x = (log x)/(log 2)
describe the three major types of RNA and their functions - ANSWER messenger
RNA, transfer RNA, and ribosomal RNA (most abundant and highly conserved)
interpret data testing whether tRNA attaches to amino acids and rRNA transmits
genetic info (incorrect) - ANSWER rRNA doesn't transmit genetic info because it
only comes in two sizes. when a cell is infected by a virus the proteins need to
change quickly which the rRNA doesn't.
In 1964, a pair of investigators discovered the function of tRNA through
experimentation (Figure 2.5). The investigators purified all of the RNA from some
actively growing pea plants and then incubated the RNA with millions of copies
of radioactive amino acid leucine. They separated all of the RNA by size and
measured presence of RNA by ultraviolet (UV) absorption. The small ran
molecules bound to the leucine
explain why it's important to use words carefully when explaining scientific ideas
- ANSWER don't use "purpose," use "function." be careful of how and why.
cells can't see or know or like
explain how genes are regulated to control RNA production - ANSWER you have
discovered that cells regulate some genes by repressors (e.g., LacI+ protein)
that respond to environmental changes (e.g., lactose). You also learned that
RNA polymerase "knows" where to start transcription for some genes based on
AT-rich segment that may denature DNA to initiate transcription.
the transcription factors bound the DNA in an all-or-none fashion, meaning that
only if all of the proteins were present could any of them bind to the promoter.
regulation, you know that promoters are composed of specific DNA sequences
and they determine at which base transcription initiates.
steroids work as transcription factors
Correct Answers
Categorize different forms of biological information (1.1) - ANSWER heritable
information provides continuity of life. non-heritable info is transmitted w/in and
b/w biological systems. information is shared knowledge (communication or
reception of knowledge); signal representing data that justifies a change
Interpret data showing that DNA is the heritable material and protein is not. (1.2
+ 1.3) - ANSWER Griffith demonstrated that the "S factor" produced more S cells
and its info was being communicated from parent to offspring. Avery extracted
water-soluble material to convert r cells -> S cells. Only DNase eliminated the
ability to transform the R cells -> S cells. Hershey + Chase blender experiment:
infer that sulfur-containing protein has no function in phage multiplication and
that DNA has some function.
Evaluate experimental design and analyze data from research on DNA as
molecular information. (1.2 + 1.3) - ANSWER Griffith's mice experiment. and then
his experiment with the cytoplasm and the cell membrane to figure out if it's DNA
or protein. membrane worked but not when washed with a buffer.
Avery's robust protocol, centrifuge, and using proteases, RNase, and DNase.
compared N/P ratio .
Hershey + Chase blender experiment with isotopes of radioactive p (in DNA) and
s (in protein). centrifuge. 80% protein not in cell and 70% dna in cells
explain the differences between S and R Streptococcus pneumoniae - ANSWER
injecting bacteria from R (rough) colonies into mice did not kill them, but
injecting bacterial S (smooth) colonies did
Compare and contrast the building blocks of DNA and proteins - ANSWER that
proteins are composed of twenty different amino acids, whereas DNA and RNA
are composed of only four different nucleotides. DNA has nitrogen and
phosphorus, proteins don't have phosphorus.
explain why amino acids make a better code than nucleotides and why biologists
were reluctant to concede that DNA was the heritable material. - ANSWER This
numerical difference (4 DNA nucleotides versus 20 amino acids) convinced the
biologists of Griffith's generation that protein was a logical choice for the
genetic code. Proteins studied more.
recognize the structure of DNA, including the nucleotides, double helix and base
pairings - ANSWER DNA composed of CHONP, nucleotides (phosphate group,
, nitrogenous base, and a 5-carbon sugar). second carbon lacks an O. A w/ T (2 h-
bonds), C w/ G (3 bonds). a and g have two rings(purines) and C and T are
pyrimidines. double helix helps with replication. Watson, crick, Wilkins, stokes,
Wilson, Franklin and gosling. 2 strands antiparallel 5' to 3'
demonstrate how DNA replication is semi-conservative - ANSWER meselson +
stahl use stable isotopes of N. 2 bands. lighter gets darker.
estimate the amount of DNA in a sample by finding the area under a curve -
ANSWER find area under graph using triangles and convert to percentages.
determine the number of generations that have passed in a population of cells -
ANSWER formula:
log_2 x = (log x)/(log 2)
describe the three major types of RNA and their functions - ANSWER messenger
RNA, transfer RNA, and ribosomal RNA (most abundant and highly conserved)
interpret data testing whether tRNA attaches to amino acids and rRNA transmits
genetic info (incorrect) - ANSWER rRNA doesn't transmit genetic info because it
only comes in two sizes. when a cell is infected by a virus the proteins need to
change quickly which the rRNA doesn't.
In 1964, a pair of investigators discovered the function of tRNA through
experimentation (Figure 2.5). The investigators purified all of the RNA from some
actively growing pea plants and then incubated the RNA with millions of copies
of radioactive amino acid leucine. They separated all of the RNA by size and
measured presence of RNA by ultraviolet (UV) absorption. The small ran
molecules bound to the leucine
explain why it's important to use words carefully when explaining scientific ideas
- ANSWER don't use "purpose," use "function." be careful of how and why.
cells can't see or know or like
explain how genes are regulated to control RNA production - ANSWER you have
discovered that cells regulate some genes by repressors (e.g., LacI+ protein)
that respond to environmental changes (e.g., lactose). You also learned that
RNA polymerase "knows" where to start transcription for some genes based on
AT-rich segment that may denature DNA to initiate transcription.
the transcription factors bound the DNA in an all-or-none fashion, meaning that
only if all of the proteins were present could any of them bind to the promoter.
regulation, you know that promoters are composed of specific DNA sequences
and they determine at which base transcription initiates.
steroids work as transcription factors
