Biochemistry 2280A Chapter Notes - Chapter 8: Microrna, Cytosine, Dicer

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sapphirebear815

1 Jan 2017

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All the cells of a multicellular organism contain the same genome: cell differentiation achieved by changes in gene expression, switching genes on and off. The difference between cells depend on the control of gene expression. Gene expression: cells selectively direct the synthesis of thousands of proteins and rnas encoded in their genome: cells become specialized producing muscle, nerve and blood cells. Cell differentiation arises because cells make and accumulate different sets of rna and protein molecules, expressing different genes. The different cell types of a multicellular organism contain the same dna. Cells have the ability to change which genes they express without altering the nucleotide sequence of their dna. If the chromosome of the differentiated cell were altered irreversibly, they would not be able to accomplish this. Dna in specialized cell types of multicellular organisms can still contain the entire set of instructions needed to form a whole organism.

Related Questions

1. Which cellular processes occur as a consequence of differential control of gene expression in eukaryotic cells?

a) Cell Differentiation

b) Differential Translation

c) Differential Polymerization

d) Differential DNA Replication

e) Differential tRNA Degradation

2) Multicellular organisms are comprised of a variety of cells with different morphologies and different functions. Which is the underlying mechanism that leads to the generation of diverse cell in one organism?

a) The expression of all genes in all cell types.

b) The duplication of the genome in certain cell types.

c) The elimination of specific group of genes from different cell types.

d) The differential expression of particular sets of genes required for a particular cellular phenotype

e) All of the above

3) Which of these statements defines paracrine cell signaling?

a)		A messenger molecule released into the blood stream to bind to a receptor on a cell far away from the release site.
b)		A messenger molecule released by a cell into the extracellular space that binds to receptors on the surface of the same cell.
c)		A messenger molecules released by a cell into the extracellular space that travels short distances to bind to a receptor in a nearby cell.
d)		A messenger molecule release by a tissue into the lumen of an organ that diffuse to bind to receptors far away from the release site.
e)		All of the above.

4) Which effect has the binding of the ligand to a G-protein coupled receptor on intracellular G-protein?

a)		ATP is hydrolyzed, activating phosphorylation
b)		GTP is exchanged for GDP on the G protein, inactivating the G protein
c)		GDP is exchanged for GTP on the G protein, activating the G protein
d)		GMP is released from the G-protein, inactivating the receptor
e)		None of the above

coffeehippopotamus191

Cell Biology (#1-5)

1) What does a non-synonymous DNA mutation cause?

a) No amino acid change

b) A change in the reading frame of the mRNA

c) The substitution of an amino acid

d) Creates a premature termination codon

e) All of the above

2) What does a non-sense DNA mutation cause?

a) No amino acid change b) Alters the normal reading frame of the mRNA

c) The substitution of an amino acid

d) Creates a premature termination codon

e) All of the above

3) If you sequence the genome of 100 cells from different tissues of the same multicellular organism. How do you expect the sequences to be?

a) 10% identical c)100% identical

b) 50% identical d) 100% different e) will depend on the tissue selected

4) Multicellular organisms are comprised of a variety of cells with different morphologies and different functions. Which is the underlying mechanism that leads to the generation of diverse cell in one organism?

a) The expression of all genes in all cell types

b) The duplication of the genome in certain cell types

c) The elimination of specific group of genes from different cell types

d) The differential expression of particular sets of genes requires for a particular cellular phenotype

e) All of the above

5)You are growing bacteria which can use lactose and glucose. The culture medium has lactose, which induces transcription of the enzymes required to use lactose. If you add glucose to the medium. What do you expect to happen?

a) The bacteria will keep using lactose

b) The bacteria will shut down the Lac operon and use glucose

c) The bacteria will stop growing

d) The bacteria will die

e) The bacteria will use both lactose and glucose

salmoneagle868

Hello can you help me with the following questions:

1. Which part of an udder was transferred to an empty oocyte to clone the sheep Dolly?

a. blastocyst (I think its this one)

b. meiotic spindle

c. intact udder cell

d. nucleus

2. What is the principle of nuclear equivalence?

a. Differentiated cells have lost DNA that codes for other cell types.

b. All nuclei are the same shape.

c. Only nuclei of germ cells contain DNA capable of producing an entire organism.

d. The genome of every somatic cell contains information capable of generating any other cell type in the body.

3. A gene contains 6 exons, numbered 1-6. Which of the following mRNA isoforms is not a possible transcriptional product of this gene?

a. 1-2-3-4-5-6

b. 2-5-3-4

c. 2-4-5-6

d. 5-6

4. Which of the following is a mechanism used to alter gene expression using mRNA transcripts?

a. Different stability (longevity) of mRNA transcripts

b. Inhibition of translation of certain mRNAs

c. Production of small RNA molecules (microRNAs) that block translation

d. All of the above

e. None of the above

5. You have recently started working in an embryology lab and have obtained a large number of unfertilized zebrafish oocytes. You decide to treat the oocytes with RNAse (a protein that will degrade RNAs, but leave DNA proteins intact) prior to fertilizing them. Will the resulting embryos develop into normal fish?

a. Yes, because RNAs from sperm cells can replace those lost from the egg.

b. Yes, because intact DNA is the only factor required for development to proceed.

c. No, because RNAse treatment will damage the structure of the oocyte.

d. No, because maternal mRNAs are required for the early stages of development.

Biochemistry 2280A Chapter Notes - Chapter 8: Microrna, Cytosine, Dicer

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