Section 4- Solution key:
1. Below is pictured the nucleus from a skin cell taken from a mouse (named Mouse #1), with the
chromosomes shown in bold.
a) Is the cell haploid or diploid?
It is diploid since the chromosomes are present in pairs.
b) Lets say we
Section 1-Solution key:
1. Organisms such as bacteria, yeasts, flies, mice and rabbits are used as model systems for different
Classify each of the above organisms as prokaryotic or eukaryotic.
Cells that lack a membrane bound
- Solution key
1. What components does the virus bring in at the time of infection?
It brings in its reverse transcriptase and genome at the time of infection
2. Why do HIV patients succumb to simplistic infections?
The HIV tar
Solution Key- 7.013 EXAM 2 (4 / 3 / 13)
Question 1 (20 points)
a) In the table below, name the sub-cellular location or organelle(s) of the eukaryotic cell that will
fluoresce when the following macromolecules are tagged with a fluorescent dye.
Solution Key- 7.013 EXAM 3 (4 / 29 / 13)
Question 1 (20 points)
Diabetes occurs either due to a reduced insulin hormone production by the pancreatic cells or the
resistance of target cells to insulin. As shown by the schematic on Page 9, insulin signaling
Solution Key- 7.013 Finals (5 / 19 / 09)
Familial adenomatous polyposis (FAP) affects nearly 1/8000 people in the USA. Patients having FAP
are genetically predisposed to colon cancer. Mutations in the APC gene have been identified as the
Solution Key- 7.013 Problem Set 1- 2013
a) With the exception of germ cells, the nucleus of all somatic cells in your body carries two copies of
each DNA segment or chromosome, which together make your genome. To fit the entire DNA into a
Solution Key- 7.013 Problem Set 2- 2013
You are working with the following parental flies (P1-P4).
P1: Light body color and normal wings
P2: Light body color and wingless
P3: Dark body color and wingless
P4: Light body color and normal wings
Solution Key- 7.013 Problem Set 3- 2013
You are analyzing the following human pedigree for a disease. Please note: The filled squares or circles
represent the abnormal phenotype. The disease related allele is rare in the population and individu
Solution key - 7.013 Problem Set 4- 2013
The following human pedigree shows the inheritance of a specific disease. Please note: The filled squares
or circles represent the abnormal phenotype. The individuals marrying into the family do not have
Solution Key- 7.013 Problem Set 5- 2013
During a summer hike you suddenly spot a huge grizzly bear. This emergency situation triggers a
fight or flight response through a signaling pathway as shown below.
Solution key- 7.013 Problem Set 6 - 2013
a) Our immune system is comprised of different cell types. Complete the table below by selecting all
correct cell types from the choices provided.
Cells types that
Choose from mast cells, macrophages, he
Solution key- 7.013 Problem Set 7 - 2013
a) Neuronal path finding is crucial for structured cellular organization and development of neural
circuits. The elongation or retraction of the growth cone is dependent on the guidance cues. You are
Section 1 8 - Solution key
1. Retinoblastoma is caused by the mutation in the retinoblastoma tumor suppressor
gene. There are several mechanisms, which can cause a cell to lose its normal gene and
thus be predisposed to develop into a tumor. These may res
Section 17 Solution key
1. Why is cancer predominantly a disease of old age? What about the usual cause of
cancer makes it more common in older people?
Cancer is caused by multiple mutations inside the same cell. The chances of a single cell ac
Solution Key- Section 16
1. Shown below is a plot of axonal membrane potential as a function of time, measured at a single
position on the axon.
For each of the three time points indicated, fill in the following table. Na
Section 2- Solution key:
1. Many glucose monomers can be linked together through glycosidic bonds to make polysaccharides
such as glycogen in animals and starch in plants. What is the advantage of storing carbohydrates as
polysaccharides as opposed to mon
Section 3- Solution key:
1. Nucleic acids are of two major types: double helical DNA and single stranded RNA.
i. Draw the chemical structure of a DNA molecule composed of three deoxy-ribonucleotides.
Label the 3 and 5 ends.
How is a nucleotide di
Section 5- Solution key:
1. In the box below, write the most likely mode of inheritance of the following pedigree?
Given each consistent mode of inheritance, if the couple in question decides to have a child, what is
SOLUTION KEY- SECTION 6
1. Say you wanted to replicate the following piece of DNA:
a) Design a 10-bp-long primer you would use to gener
S O L U T I O N K E Y - S E C T I O N 7
1. S h ow n bel ow i s th e gen om i c s tr u ctu r e of th e h u m an b- gl obi n gene. T he n u m ber s w i thi n the box es
i n d icate th e len gth ( in n u cleotid es ) of each r egion . T h e D N A s equ ences
SOLUTION KEY- SECTION 8
1. Assume that the sequence of DNA below is a short protein-encoding gene; the sequences in between
the transcription start and stop sites are shown. The entire DNA sequence of the very short gene is:
SOLUTION KEY- SECTION 9
1. Three restriction enzymes have recognition sites in a plasmid: EcoRI (E), HindIII (H), and XbaI
(X). You digest the plasmid with each of the following combinations of enzymes and see the
SOLUTION KEY- SECTION 10
1. How is a cDNA library different from a genomic library?
A genomic library is a population of host bacteria, each of which carries a DNA fragment that was inserted into
a cloning vector, such that the collection of cloned DNA fr
SOLUTION KEY- SECTION 11
1. You are interested in four different proteins in a yeast cell: protein 1 is a cytosolic protein, protein 2 is
a secreted protein, protein 3 is a nuclear protein and protein 4 is a transmembrane protein. You plan to
study how th
SOLUTION KEY- SECTION 12
1. The wnt signaling pathway is one of the most important in biology. It is required for cell proliferation
and its inhibition leads to programmed cell death. As diagrammed below
Wnt ligands bind to frizzled receptors.
Solution Key- Section 13
2. This question is about development of the alimentary canal (the gut) from the endodermal cell
layer of the mouse embryo. This process requires contact between the endoderm (unshaded, labeled A,
B, C, D in the diagrams below) an
Solution Key- Section 14
1. Classify the following as totipotent, pluripotent, bipotent, unipotent or differentiated:
a) Cells that can differentiate into many cell types. Pluripotent
b) A zygote that is about to start cleavage. Totipotent (it c
Section 15- Solution key
1. Viral infections can be treated using anti-viral drugs, or they can be prevented in the first place
through the use of vaccines. Some vaccines are just injections of viral particles that have been
inactivated in some
Running head: ESSAY QUESTIONS
1. Explain the classification system used in biology to organize living creatures. Pick two organisms from
each Kingdom and explain why th