Bio 200 Exam 2 Study Guide Questions
and Answers
What is the significance of a recombination frequency of 50%? - ANSWER-The
genes are on separate chromosomes
Is it possible to have a recombination rate significantly greater than 50%? (80 or
90%) - ANSWER-No, 50% is the largest rate because anything above would be
independent assortment with genes on different chromosomes
Why are recombination frequencies not additive? - ANSWER-the number of cross
over events on a chromosome are additive, but the frequencies are not because the
recombination frequency is not a linear function with cross overs
Cross overs are the cause and recombination is the result, so not in a 1:1 ratio
Is it possible for a cross of two green parakeets to produce a white parakeet? How
would this work? - ANSWER-Yes. Parakeet feather color is controled by two genes
that are dominant for blue and black colors on the B gene and dominant for yellow
color on the C gene. For each gene, if a homologous recessive genotype is
produced, the offspring will not express that color and white will be expressed. Green
parakeets could have genotypes of BbCc or BBCC, but for a white offspring, both
parents must have a heterozygous genotype so be able to each pass on the
recessive B and C gene.
What's the principle difference between prokaryotes and eukaryotes? - ANSWER-
Prokaryotes have no nucleus (ex: bacteria and archaea). They have limited types of
organelles, limited cytoskeleton and are small.
Eukaryotes have a nucleus and membrane bound organelles and are large.
What is the cytoskeleton? Name a major cytoskeletal protein. - ANSWER-Part of a
cell that contains microtubules, actin filaments, and intermediate filaments that give
the cell its shape and allow for cell division and organization of organelles
What is the endoplasmic reticulum? (function) - ANSWER-Folds protein molecules in
cisternae and transport synthesized proteins in vesicles to golgi apparatus
What is the golgi apparatus? (function) - ANSWER-Made of membrane bound sacs
that processes and bundle macromolecules (lipids and carbohydrates)
Name the 4 major classes of biological macromolecules. Name the monomers that
make up each of these polymers. - ANSWER-Lipids- fatty acids
Carbohydrates- sugars
Nucleic acids- nucleotides
Proteins- amino acids
, Draw the basic structure of an amino acid - ANSWER-N-C-C back bone
"N" has 2 H's attached (amino group)
middle C is the alpha carbon and has an R group attached and a H
outer C has a double bonded O and an OH (carboxyl group)
When an amino acid is dissolved in water, what generally happens to its amino (-
NH2) group? to its carboxyl group (-COOH)? - ANSWER-Carboxyl is an organic acid
that donates an H+ and the amino is an organic base that accepts an H+
H2O is formed in the process
Pick out any 2 amino acids. Draw a peptide bond between them. - ANSWER-
What is the primary structure of a polypeptide? Secondary structure? Tertiary?
Quaternary? - ANSWER-Primary structure is the linear sequence of amino acids
Secondary structure is the localized folding stabilized by H-bonds. Beta sheets and
alpha helices are common patterns
Tertiary structures are the overall 3D structure stabilized by all kinds of bonds and
interactions (examples of interactions are hydrophobic interactions and covalent
sulfur to sulfur bonds between cysteine residues)
Quaternary structure is made up of subunits of tertiary structures (more than one
amino acid chain)
Describe the phospholipid bilayer - ANSWER-Hydrophilic head made of a polar
group, phosphate and glycerol and two hydrophobic fatty acid tails
What kinds of chemical bonds stabilize secondary structure? - ANSWER-Hydrogen
bonds
What kinds of chemical bonds stabilize tertiary and quaternary structure? -
ANSWER-Hydrophobic interactions, disulfide bonds, hydrogen bonds, ionic bonds
What bonds the monomers of starch and cellulose? - ANSWER-Starch: alpha 1,4
glycosidic bonds
Cellulose: beta 1,4 glycosidic bonds
What is a prosthetic group? - ANSWER-Part of an protein that is not an amino acid
and is necessary for the function of the protein
What is the distinction between a protein and a polypeptide? - ANSWER-A
polypeptide is a polymer made up of amino acids joined by peptide bonds. A protein
is a functional unit made up of one or more polypeptides and their associated
prosthetic group
Which amino acid has an R group that can form covalent bonds? And what's the
significance of its ability to do this? - ANSWER-Cysteine is an important among acid
because is forms disulfide bonds.
The R group is SH and it stabilizes the tertiary or quaternary structure
Are most R groups basic? acidic? large? small? - ANSWER-there is large variety
and Answers
What is the significance of a recombination frequency of 50%? - ANSWER-The
genes are on separate chromosomes
Is it possible to have a recombination rate significantly greater than 50%? (80 or
90%) - ANSWER-No, 50% is the largest rate because anything above would be
independent assortment with genes on different chromosomes
Why are recombination frequencies not additive? - ANSWER-the number of cross
over events on a chromosome are additive, but the frequencies are not because the
recombination frequency is not a linear function with cross overs
Cross overs are the cause and recombination is the result, so not in a 1:1 ratio
Is it possible for a cross of two green parakeets to produce a white parakeet? How
would this work? - ANSWER-Yes. Parakeet feather color is controled by two genes
that are dominant for blue and black colors on the B gene and dominant for yellow
color on the C gene. For each gene, if a homologous recessive genotype is
produced, the offspring will not express that color and white will be expressed. Green
parakeets could have genotypes of BbCc or BBCC, but for a white offspring, both
parents must have a heterozygous genotype so be able to each pass on the
recessive B and C gene.
What's the principle difference between prokaryotes and eukaryotes? - ANSWER-
Prokaryotes have no nucleus (ex: bacteria and archaea). They have limited types of
organelles, limited cytoskeleton and are small.
Eukaryotes have a nucleus and membrane bound organelles and are large.
What is the cytoskeleton? Name a major cytoskeletal protein. - ANSWER-Part of a
cell that contains microtubules, actin filaments, and intermediate filaments that give
the cell its shape and allow for cell division and organization of organelles
What is the endoplasmic reticulum? (function) - ANSWER-Folds protein molecules in
cisternae and transport synthesized proteins in vesicles to golgi apparatus
What is the golgi apparatus? (function) - ANSWER-Made of membrane bound sacs
that processes and bundle macromolecules (lipids and carbohydrates)
Name the 4 major classes of biological macromolecules. Name the monomers that
make up each of these polymers. - ANSWER-Lipids- fatty acids
Carbohydrates- sugars
Nucleic acids- nucleotides
Proteins- amino acids
, Draw the basic structure of an amino acid - ANSWER-N-C-C back bone
"N" has 2 H's attached (amino group)
middle C is the alpha carbon and has an R group attached and a H
outer C has a double bonded O and an OH (carboxyl group)
When an amino acid is dissolved in water, what generally happens to its amino (-
NH2) group? to its carboxyl group (-COOH)? - ANSWER-Carboxyl is an organic acid
that donates an H+ and the amino is an organic base that accepts an H+
H2O is formed in the process
Pick out any 2 amino acids. Draw a peptide bond between them. - ANSWER-
What is the primary structure of a polypeptide? Secondary structure? Tertiary?
Quaternary? - ANSWER-Primary structure is the linear sequence of amino acids
Secondary structure is the localized folding stabilized by H-bonds. Beta sheets and
alpha helices are common patterns
Tertiary structures are the overall 3D structure stabilized by all kinds of bonds and
interactions (examples of interactions are hydrophobic interactions and covalent
sulfur to sulfur bonds between cysteine residues)
Quaternary structure is made up of subunits of tertiary structures (more than one
amino acid chain)
Describe the phospholipid bilayer - ANSWER-Hydrophilic head made of a polar
group, phosphate and glycerol and two hydrophobic fatty acid tails
What kinds of chemical bonds stabilize secondary structure? - ANSWER-Hydrogen
bonds
What kinds of chemical bonds stabilize tertiary and quaternary structure? -
ANSWER-Hydrophobic interactions, disulfide bonds, hydrogen bonds, ionic bonds
What bonds the monomers of starch and cellulose? - ANSWER-Starch: alpha 1,4
glycosidic bonds
Cellulose: beta 1,4 glycosidic bonds
What is a prosthetic group? - ANSWER-Part of an protein that is not an amino acid
and is necessary for the function of the protein
What is the distinction between a protein and a polypeptide? - ANSWER-A
polypeptide is a polymer made up of amino acids joined by peptide bonds. A protein
is a functional unit made up of one or more polypeptides and their associated
prosthetic group
Which amino acid has an R group that can form covalent bonds? And what's the
significance of its ability to do this? - ANSWER-Cysteine is an important among acid
because is forms disulfide bonds.
The R group is SH and it stabilizes the tertiary or quaternary structure
Are most R groups basic? acidic? large? small? - ANSWER-there is large variety
