What are the main epigenetic mechanisms that interfere with the expression of genes?

CRCs (chromatin remodeling complexes) drive the formation of heterochromatin regardless of any regulatory input.

CRCs condense chromatin in centromeres, telomeres and origins of replication. gene-rich genomic DNA regions that are not condensed by CRCs (chromatin remodeling complexes) are able to be accessed by transcription factors that may activate or repress transcription (gene expression).

CRCs (chromatin remodeling complexes) locally (regionally) reorganize global chromatin structure making it inaccessible (by condensing) or accessible (by relaxing) to transcription factors.

CRCs (chromatin remodeling complexes) recognize certain labels, chemical modifications on specific amino acids side chains on histone tail domains and as a response promote the condensation or relaxation of chromatin regions preventing or allowing transcription to occur, respectively.

Arrange the following steps in E. coli translation from first (1) to last (9).

Dissociation of the peptide chain as well as the large and small ribosomal subunits from the complex.

Recruitment of the 50S subunit to form a completed initiation complex in a GTP-dependent manner.

Translocation of uncharged tRNA from P site to E site of the ribosome, and docking of the next charged tRNA at the A site.

A stop codon is encountered at the A site. Peptide bond formation between two adjacent amino acids catalyzed by peptidyl transferase.

Release factor recognizes a stop codon, and the bond between tRNA and the nascent polypeptide chain is broken.

Binding of a charged tRNA to the aminoacyl (A) site of the ribosome complex.

fMet-tRNAfMet recognizes the initiator codon AUG and binds to it.

The small ribosomal subunit binds to the ribosome binding site.

elect the correct answer from the pull down menu.

choose from this list:

stop codon

reverse transcriptase inhibitor

latent

polypeptide chain

protein synthesis

genome

rna polymerse

host cell

carcinogen

hydrogen

a)The urea cycle:The reciprocal substrate relationship (ATP vs GTP) in purine nucleotide synthesis ensures a balanced pool of adenine nucleotide and guanidine nucleotide be available for the synthesis of nucleic acid. True/False?

b) The urea cycle:converts urea to ammonia and carbon dioxide.True/False?

c) The urea cycle: acts as an energy-supplying mechanism by oxidizing waste materials.True/False?

d) The urea cycle:converts ammonia into urea. True/False?

e) The urea cycle:converts urea into uric acid. True/False?

f) The urea cycle:supplies the bodily requirement for arginine in adults. True/False?

g) For mammals, some amino acids are essential in the diet, whereas others may be formed from dietary components. Humans are capable of converting: oxaloacetate to aspartic acid. True/False?

1.   In the proximal tubule under normal conditions, 50% of glucose is reabsorbed back into the peritubular capillaries.
a.   true
b.   false

2.   The transport maximum (Tmax) is the upper limit of reabsorption of glucose and amino acids due to the saturation of carrier systems that return these substances back to the blood.
a.   true
b.   false

3.   Which of the following is an effect of aldosterone? MIGHT BE C***
a.   excretion of sodium ions
b.   conservation of potassium ions
c.   conservation of sodium ions
d.   all are correct

4.   Some hydrogen ions secreted into the collecting duct are buffered. These buffers are
a.   bicarbonate buffers
b.   ammonia (NH3)
c.   phosphate buffers
d.   all of the above

5.   The glomerular filtration rate average in an adult male is 125 ml/min. (Might be F)
a.   true
b.   false

1. Antibodies against both type A and type B red blood cell antigens are found in the plasma of a person whose blood is:
a)any of these types

b)type O

c)type A

d)type AB

e)type B

2.What plasma protein helps draw water from tissues into capillaries to maintain blood volume and pressure?

a)albumin

b)gamma globulins

c)fibrinogen

d)beta globulins

e)alpha globulins

3) Fibrinogen is to fibrin as
a)amino acids are to proteins

b)deoxyribonucleotides are to DNA

c)All of these choices

d)ribonucleotides are to RNA

4)Sympathetic neurons could
a)speed up the heart beat

b)slow down the heart beat

d)would have no effect on the heart beat

Match the following descriptions to the most appropriate method of genome engineering presented within the list. Use each answer once. List: MuGENT, Transformation, CRISPR, Transposon mutagenesis, and MAGE.

a. You are attempting to see the effect of substituting similar amino acids across the genome (called conservative replacement). Thus, by using _____ you try and replace all glycine codons with alanines.

b. You are looking to create a heterogenous mixture of knockout mutants from a pool of 6 genes.

c. A broadly-applicable technique that can make efficient gene edits based on guide RNA.

d. You are looking to randomly disrupt genes within the genome to assess their function.

e. Using a PCR fragment with homology to the genome, you must get this DNA into your target cells somehow...

3. Fit a multiple regression model that relates the salary to education, work experience, and time spent at the bank so far.

a - State what your model is.

b - Determine whether the independent variables are significant, or not, at a level of significance of 5%.

c - Which independent variable is most significant in explaining salary? Which is least significant?

d - Is your overall model significant? Provide statistical proof by conducting an F-test for overall fit of the regression. State the hypothesis to be tested, the p-value for your F-statistic, and your decision. How much weight of evidence is there in rejecting the null hypothesis?

This data set was obtained by collecting information on a randomly selected sample of 93 employees working at a bank.

SALARY- starting annual salary at the time of hire

EDUC   - number of years of schooling at the time of the hire

EXPER - number of months of previous work experience at the time of hire

TIME    - number of months that the employee has been working at the bank until now

2. Use the least squares method to fit a simple linear model that relates the salary (dependent variable) to education (independent variable).

a- What is your model? State the hypothesis that is to be tested, the decision rule, the test statistic, and your decision, using a level of significance of 5%.

b – What percentage of the variation in salary has been explained by the regression?

c – Provide a 95% confidence interval estimate for the true slope value.

d - Based on your model, what is the expected salary of a new hire with 12 years of education?

e – What is the 95% prediction interval for the salary of a new hire with 12 years of education? Use the fact that the distance value = 0.011286

QUESTION 1

1. In a cross of AABB x aabb, how frequent are the individuals displaying the recessive trait for both genes in the F1 offspring?

   		0
   		1/16
   		3/16
   		9/16
   		100%

QUESTION 2

1. If the amino acid sequence of the polypeptide chain below is written in the direction of its translation from the mRNA (from left to right), which amino acid has an exposed amino group?
   Met Phe Leu Ser Tyr Cys Pro His Gln Arg Ile Thr

   		Met
   		Thr
   		Phe at the second position
   		Both (a) and (b)
   		None of the above.

QUESTION 3

1. In order for a human (or another mammal) to grow to its normal size, the igf gene encoding the insulin-like growth factor

   		has to be imprinted in exactly the same way in both the sperm and the ovum.
   		has to be imprinted in different ways (has to carry different epigenetic marks) in the sperm and in the ovum.
   		cannot be imprinted (cannot have any epigenetic mark whatsoever) in the gametes by either the male or the female parent.
   		has to be deleted in the sperm, but not in the ovum.
   		None of the above.

QUESTION 4

1. Lac operon transcription is _____________when the operator sequence is eliminated by a mutation

   		induced by the presence of glucose.
   		repressed
   		constitutive
   		not influenced at all
   		entirely blocked