BIOMG 1350 Chapter Notes - Chapter 8: Gene Expression, Transcriptional Regulation, Multicellular Organism

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fuchsiadog160

7 Nov 2016

School

Cornell University

Department

Molecular Biology and Genetics

Course

BIOMG 1350

Professor

Huffaker

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Document Summary

Gene expression: how cells selectively direct the synthesis of proteins and rnas. Differentiation: cells make and accumulate different sets of rna and protein molecules, express different genes. The different cell types of a multicellular organism contain the same dna. Different cell types produce different sets of proteins: house-keeping proteins. Rna polymerases, dna repair enzymes, etc: specialized proteins. Responsi(cid:271)le for (cid:272)ell"s distin(cid:272)tive properties: gene e(cid:454)pression (cid:272)an (cid:271)e studied (cid:271)(cid:455) (cid:272)ataloging (cid:272)ell"s rnas. A cell can change the expression of its genes in response to external signals: steroid hormones, affects transcription of mrna for certain proteins. Gene expression can be regulated at various steps from dna to rna to protein: can control proteins it contains by: Controlling when and how often a gene is transcribed. Controlling how an rna transcript is spliced or processed. Selecting which mrnas are exported from nucleus to cytosol. Regulating how quickly certain mrna molecules are degraded. Selecting which mrnas are translated into proteins by ribosomes.

Related Questions

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.

13. The arms of a human and the wing of a bat are _________________ structures, composed of the same bones that have been modified for different functions.

analogous

vestigial

c.	homologous

d.	convergent

14. Xeroderma pigmentosum is an autosomal recessive genetic disorder. People who are homozygous for the disease-causing allele have skin that is damaged by exposure to ultraviolet radiation; this can lead to skin cancer at an early age. The mutation that causes this disorder is in a gene that functions:

a.	to repair DNA by excising (removing) nucleotides damaged by UV light.

b.	in lysosomes, to break down lipids that otherwise accumulate in the nervous system.

c.	to produce the UV blocking pigment melanin in the skin cells

d.	in red blood cells to carry oxygen to the skin.

15. The Amish are a religious sect descended from a small group of colonists who came to the United States over 200 years ago. Their religious beliefs have kept them isolated from society. The Amish have a much higher than average incidence of both polydactyly (extra fingers and toes) and dwarfism in their communities. This is most likely explained by:

a.	inheritance of acquired characters.

b.	the founder effect.

c.	disruptive selection.

d.	natural selection.

16. In the structure of DNA that Watson and Crick proposed, the sides of the "ladder" of the DNA molecule are always the same distance apart, making the molecule a constant width. This occurs because when the bases hydrogen bond to form the rungs of the "ladder", a:

a.	purine always pairs with a pyrimidine.

b.	purine always pairs with a purine.

c.	pyrimidine always pairs with a pyrmidine.

d.	The structure of the double helix is not determined by how the bases pair.

17. The RNA transcript of DNA that travels to the cytoplasm, carrying the instructions to make a protein, is called:

rRNA.

tRNA.

mRNA.

d.	RNA polymerase.

18. When DNA is replicated, the error rate is approximately one error for every 10,000 nucleotides copied. However, that error rate is reduced to only 1 error for every 1 billion nucleotides. The DNA sequence is "corrected" by:

a.	repeating S phase to see if the error rate is lower the second time around.

b.	enzymes that proofread the DNA and repair errors.

c.	messenger RNA during the process of transcription.

d.	Any errors made during DNA replication cannot be corrected. If errors are detected after S phase, the cell is destroyed.

19. Mendel's principle of segregation says that:

a.	when gametes are formed, each gamete receives only one allele for a particular gene.

b.	some genes are dominant to others.

c.	a testcross must be used to determine the genotype of an organism with a dominant phenotype.

d.	all of the above

20. Tay-Sachs disease is lethal before reproductive age, but the allele persists in Louisiana French Canadians because:

a.	it is a dominant allele.

b.	new mutations causing this disease are common in that population.

c.	it is not expressed in the phenotype of heterozygous individuals.

d.	the disease is contagious and can be transmitted by nonheritable means.

21. Physical features that are similar in organisms which are not closely related to each other are most likely a result of ____________. A good example of this is the similarities seen between some marsupial and placental mammals.

a.	natural selection.

b.	adaptation to similar environments

c.	convergent evolution

d.	All of the above phrases can be used to correctly fill this blank.

22. In humans, which of the following sex chromosome compliments could be found in males?

23. The proteins that are associated with eukaryotic chromosomes:

a.	help to package the DNA within the nucleus.

b.	are involved in gene expression, through binding with the DNA.

c.	may be replicating or transcribing the DNA.

d.	All of these are true of proteins that are associated with eukaryotic chromosomes.

24. A sequence of DNA nucleotides that contains the information to produce a single protein is a(n):

codon.

gene.

c.	polypeptide.

d.	anticodon.

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BIOMG 1350 Chapter Notes - Chapter 8: Gene Expression, Transcriptional Regulation, Multicellular Organism

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