BIOL 112 Lecture Notes - Lecture 17: Xist (Gene), Cpg Site

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27 Oct 2014

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BIOL 112 Full Course Notes

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Biol 112 - biology of the cell - lecture 17 (chapter 19): transcription. Hundreds of genes contribute to the production of one trait. Answer: this is controlled by gene regulation. Gene expression can be influenced by chemical modification of dna or histones. Near the promoter (starting point of transcription), there can be clusters of cytosine- guanine pairs. This cluster is referred to as cpg island. Add methyl group to cpg, the transcription for the gene is suppressed. No methyl group to cpg, the gene is still active. The image of the modification to cpg island. Chromatin is the coiled structure of a threat of nucleosomes. Each nucleosome is 150 base pairs of dna wrapped around a histone protein. Chromatin is not accessible to transcriptional proteins. Histone proteins have strings of amino acids protruding - histone tails. Methyl groups or acetyl groups are added. Addition of chemical groups is referred to as histone coding.

Related Questions

1. What reaction is catalyzed by reverse transcriptase and used in the laboratory to generate cDNA?

a. transcription of RNA to DNA

b. transcription of DNA to RNA

c. conversion of ribonucleotides into deoxyribonucleotides

d. translation of RNA to DNA

e. conversion of a ribonucleotide to a DNA double helix

2. In eukaryotic cells, _________determine the amount of mRNA arising from a particular gene.

a. transcriptional-level controls

b. RNA processing-level controls

c. translational-level controls

d. replication-level controls

e. b and c

3. In eukaryotic cells, _________determine how a primary transcript is converted to mature mRNA

a. transcriptional-level controls

b. RNA processing-level controls

c. translational-level controls

d. replication-level controls

e. a and d

4. In eukaryotic cells, _________determine when a particular mRNA is actually used in protein synthesis.

a. transcriptional-level controls

b. RNA processing-level controls

c. translational-level controls

d. replication-level controls

e. None of the above because protein synthesis takes place immediately

5. Under what circumstances do cells selectively activate and suppress their genes?

a. at different stages of embryonic development

b. in different tissues

c. exposure to different types of stimuli

d. No such circumstances exist in natureâcells express all their genes throughout life.

e. a, b and c

6. Which statement about the control of gene expression is FALSE?

a. A single gene may be controlled by different transcription factors.

b. A single transcription factor may be necessary for the expression of different genes.

c. Each cell type has a characteristic pattern of gene transcription, which is determined by the particular complement of transcription factors contained in that cell.

d. Expression of protein genes is primarily controlled in nucleoli

e. Control of gene transcription is complex and influenced by various circumstances.

7. What is thought to maintain X chromosome inactivation in females?

a. DNA acetylation

b. DNA methylation

c. RNA inactivation

d. Histone methylation

e. None of the above because both X chromosomes are active in females and males.

crimsonplatypus494

2. In eukaryotic cells, _________determine the amount of mRNA arising from a particular gene.

a. transcriptional-level controls

b. RNA processing-level controls

c. translational-level controls

d. replication-level controls

e. b and c

3. In eukaryotic cells, _________determine how a primary transcript is converted to mature mRNA

a. transcriptional-level controls

b. RNA processing-level controls

c. translational-level controls

d. replication-level controls

e. a and d

4. In eukaryotic cells, _________determine when a particular mRNA is actually used in protein synthesis.

a. transcriptional-level controls

b. RNA processing-level controls

c. translational-level controls

d. replication-level controls

e. None of the above because protein synthesis takes place immediately

5. Under what circumstances do cells selectively activate and suppress their genes?

a. at different stages of embryonic development

b. in different tissues

c. exposure to different types of stimuli

d. No such circumstances exist in natureâcells express all their genes throughout life.

e. a, b and c

6. Which statement about the control of gene expression is FALSE?

a. A single gene may be controlled by different transcription factors.

b. A single transcription factor may be necessary for the expression of different genes.

c. Each cell type has a characteristic pattern of gene transcription, which is determined by the particular complement of transcription factors contained in that cell. d. Expression of protein genes is primarily controlled in nucleoli

e. Control of gene transcription is complex and influenced by various circumstances.

7. What is thought to maintain X chromosome inactivation in females?

a. DNA acetylation

b. DNA methylation

c. RNA inactivation

d. Histone methylation

e. None of the above because both X chromosomes are active in females and males.

periwinklehorse209

QUESTION 1

How is a bone marrow transplant able to treat someone with leukemia?

		The donor blood contains antibodies that destroy cancer cells
		Donor blood contains stem cells that regenerate cells in the immune system
		Bone marrow contains induced pluripotent stem cells that turn into red blood cells
		Bone marrow contains tumor supressor genes that slow down leukemia growth
		Bone marrow contains pluripotent human embryonic stem cells

1.2 points

QUESTION 2

What would happen if siRNAs designed to target mRNA from an oncogene were introduced into cancer cells?

		Increased genomic instability would result from adding foreign nucleic acids
		New mutations would arise in the oncogene
		The oncogene would be converted back into a proto-oncogene
		The siRNAs would compete with the oncogene's active site
		Production of the oncogene protein would decrease

1.2 points

QUESTION 3

What is the purpose of chromatin-remodeling enzymes in human cells?

		The enzymes control the rate of translation of an mRNA transcript
		The enzymes add phosphate or methyl groups to histone tails
		The enzymes slide nucleosomes farther apart or closer to each other
		The enzymes send damaged proteins to the proteasome for degradation
		The enzymes cause DNA looping to occur

1.2 points

QUESTION 4

If you wanted to resurrect the mammoth, how would you do it?

		Use somatic cell nuclear transfer to insert the mammoth genome into the egg of an elephant
		Use transcription factors to re-program adult cells from elephants into mammoth cells
		Change the gene expression patterns of elephants to increase production of mammoth genes
		Use siRNAs to decrease expression of elephant-specific genes in an elephant embryo

1.2 points

QUESTION 5

How is eukaryotic transcription initiated?

		RNA polymerase is recruited to the start codon by transcription factors
		RNA polymerase begins transcription at the enhancer sequence
		RNA polymerase is activated by binding to GTP
		An initiator tRNA binds to the ribosome
		A complex of proteins forms at the promoter of a gene

BIOL 112 Lecture Notes - Lecture 17: Xist (Gene), Cpg Site

BIOL 112 Full Course Notes

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