BIO 100 - EXAM 2 QUESTIONS AND
ANSWERS.
Insulin is a protein that is produced by pancreatic cells and secreted into the bloodstream. Since
all the cells in a person's body contain the same DNA, why do only our pancreatic cells produce
insulin? - Answer Because some of our cells can be turned on or off to fulfill certain functions
If we insert the human gene for insulin into bacteria, the bacteria will produce human insulin.
How is this possible? - Answer Because bacteria can reproduce asexually, cells can code and
decode to proteins as normal humans
After sequencing a molecule of DNA, you discover that 20% of the bases are cytosine (C). What
percentage of the bases would you expect to be guanine (G)? What percentage of the bases
would you expect to be thymine (T)? - Answer There will be 20% Guanine because Guanine
and Cytosine are complimentary, this leaves 60% to be Thymine
Since DNA is contained in the nucleus of eukaryotic cells but protein synthesis occurs at
ribosomes outside of the nucleus, how is the information in DNA conveyed to the ribosomes? -
Answer Through mRNA and transcription
How many nucleotides are necessary to code for a protein that is 100 amino acids long? -
Answer 300 (1 amino acid = 3 nucleotides)
The DNA coding strand for a gene is AGT ATG GCC CGT ACA and reads from left to right. What
messenger RNA would be sent to the cytoplasm? What about the amino acid (AA) sequence? -
Answer UCA UAC CGG GCA UGU
How many different types of gametes could a person with the genotype AABbCc produce? -
Answer 4 types of gametes
ABC Abc ABc AbC
DNA paternity testing has become the most widely accepted method for establishing who the
father of a child is when there are doubts. In one case the mother refused to supply a sample of
her DNA, but the man claiming to be the father had his DNA and that of the baby's taken and
analyzed. Is it possible to establish who the father is in this method even if the mother's DNA is
not available to compare? - Answer Yes, because the child receives equal DNA from the
mother and father, because you are testing for DNA from the father the mother's DNA is not
needed
For some time, Russian prisons have been running on drastically reduced budgets. As a result,
when inmates contracted tuberculosis (TB; caused by an infection of the lungs by a particular
, bacteria species), treatment with antibiotics was often halted before all TB bacteria had been
killed by the antibiotics in an infected prisoner. It is now observed that strains of antibiotic
resistant TB have appeared in the Russian prison population. Such strains have now reached the
United States when freed prisoners have emigrated. Based on what we've learned so far this
semester, what might provide a scientifically valid explanation of the appearance of antibiotic-
resistant TB? - Answer They became resistant to tuberculosis because they were not given
enough/strong enough treatment to eliminate TB
A gene for red-green color blindness (daltonism) is carried on the "X" chromosome. It is only
expressed phenotypically as homozygous recessive in women but men that inherit the affected
chromosome will suffer from the disorder. What are the possible genotypes for a man and
woman with color blindness and for a man and woman with "normal" color vision? - Answer
Colorblind women genotype: X^bX^b
Colorblind men genotype: X^bY
Normal women genotype: XX, XX^b
Normal men genotype: XY
What percent of their male children will be affected by color blindness? (punnet square) -
Answer 100%
What percent of their female children will be affected by color blindness? (punnet sqaure) -
Answer 0%
A "normal" man is going to marry a "normal" woman who already has had a color-blind son by
another man. What are the probabilities of this new marriage producing a color-blind child?
(punnet square) - Answer 25% chance of being colorblind
Genetic inheritance is being studied in a certain species of plant in which orange flower color
(O) is dominant to white (o) and round leaf shape (S) is dominant to oval (s). A true-breeding
orange-flowered, round-leaved male plant (Plant A) is mated with a true-breeding white-
flowered, oval-leaved female plant (Plant B) to produce a dihybrid offspring plant (Plant C).
Assuming normal Mendelian genetics and independent inheritance of these two traits, which
gametes might be produced by Plant C? - Answer OS, Os, oS, os
Suppose male fruit flies with the HHNN genotype mate with female flies with the hhnn
genotype. H= hairy legs, h= hairless legs; N= normal wings, n=shriveled wings. About what
percentage of offspring flies will have hairy legs and normal wings? (punnet square) - Answer
100%
What are the mechanisms of evolution? How do they differ? - Answer Mutation refers to the
change in the genetic makeup of an organism affecting the gene pool of a population.
ANSWERS.
Insulin is a protein that is produced by pancreatic cells and secreted into the bloodstream. Since
all the cells in a person's body contain the same DNA, why do only our pancreatic cells produce
insulin? - Answer Because some of our cells can be turned on or off to fulfill certain functions
If we insert the human gene for insulin into bacteria, the bacteria will produce human insulin.
How is this possible? - Answer Because bacteria can reproduce asexually, cells can code and
decode to proteins as normal humans
After sequencing a molecule of DNA, you discover that 20% of the bases are cytosine (C). What
percentage of the bases would you expect to be guanine (G)? What percentage of the bases
would you expect to be thymine (T)? - Answer There will be 20% Guanine because Guanine
and Cytosine are complimentary, this leaves 60% to be Thymine
Since DNA is contained in the nucleus of eukaryotic cells but protein synthesis occurs at
ribosomes outside of the nucleus, how is the information in DNA conveyed to the ribosomes? -
Answer Through mRNA and transcription
How many nucleotides are necessary to code for a protein that is 100 amino acids long? -
Answer 300 (1 amino acid = 3 nucleotides)
The DNA coding strand for a gene is AGT ATG GCC CGT ACA and reads from left to right. What
messenger RNA would be sent to the cytoplasm? What about the amino acid (AA) sequence? -
Answer UCA UAC CGG GCA UGU
How many different types of gametes could a person with the genotype AABbCc produce? -
Answer 4 types of gametes
ABC Abc ABc AbC
DNA paternity testing has become the most widely accepted method for establishing who the
father of a child is when there are doubts. In one case the mother refused to supply a sample of
her DNA, but the man claiming to be the father had his DNA and that of the baby's taken and
analyzed. Is it possible to establish who the father is in this method even if the mother's DNA is
not available to compare? - Answer Yes, because the child receives equal DNA from the
mother and father, because you are testing for DNA from the father the mother's DNA is not
needed
For some time, Russian prisons have been running on drastically reduced budgets. As a result,
when inmates contracted tuberculosis (TB; caused by an infection of the lungs by a particular
, bacteria species), treatment with antibiotics was often halted before all TB bacteria had been
killed by the antibiotics in an infected prisoner. It is now observed that strains of antibiotic
resistant TB have appeared in the Russian prison population. Such strains have now reached the
United States when freed prisoners have emigrated. Based on what we've learned so far this
semester, what might provide a scientifically valid explanation of the appearance of antibiotic-
resistant TB? - Answer They became resistant to tuberculosis because they were not given
enough/strong enough treatment to eliminate TB
A gene for red-green color blindness (daltonism) is carried on the "X" chromosome. It is only
expressed phenotypically as homozygous recessive in women but men that inherit the affected
chromosome will suffer from the disorder. What are the possible genotypes for a man and
woman with color blindness and for a man and woman with "normal" color vision? - Answer
Colorblind women genotype: X^bX^b
Colorblind men genotype: X^bY
Normal women genotype: XX, XX^b
Normal men genotype: XY
What percent of their male children will be affected by color blindness? (punnet square) -
Answer 100%
What percent of their female children will be affected by color blindness? (punnet sqaure) -
Answer 0%
A "normal" man is going to marry a "normal" woman who already has had a color-blind son by
another man. What are the probabilities of this new marriage producing a color-blind child?
(punnet square) - Answer 25% chance of being colorblind
Genetic inheritance is being studied in a certain species of plant in which orange flower color
(O) is dominant to white (o) and round leaf shape (S) is dominant to oval (s). A true-breeding
orange-flowered, round-leaved male plant (Plant A) is mated with a true-breeding white-
flowered, oval-leaved female plant (Plant B) to produce a dihybrid offspring plant (Plant C).
Assuming normal Mendelian genetics and independent inheritance of these two traits, which
gametes might be produced by Plant C? - Answer OS, Os, oS, os
Suppose male fruit flies with the HHNN genotype mate with female flies with the hhnn
genotype. H= hairy legs, h= hairless legs; N= normal wings, n=shriveled wings. About what
percentage of offspring flies will have hairy legs and normal wings? (punnet square) - Answer
100%
What are the mechanisms of evolution? How do they differ? - Answer Mutation refers to the
change in the genetic makeup of an organism affecting the gene pool of a population.
