Chapter 17, Problem 1P

For each of the terms in the left column, choose the best matching phrase in the right column.

a.	basal factors	1.	organizes enhancer/promoter interactions
a.	repressors	2.	pattern of expression depends on which parent transmitted the allele
a.	CpG	3.	activates gene transcription temporal- and tissue-specifically
a.	imprinting	4.	site of DNA methylation
a.	miRNA	5.	identifies DNA-binding sites of transcription factors
a.	coactivators	6.	bind to enhancers
a.	epigenetic effect	7.	bind to promoters
a.	insulator	8.	bind to activators
a.	enhancer	9.	prevents or reduces gene expression posttranscriptionally
a.	ChIP-Seq	10.	heritable change in gene expression not caused by DNA sequence mutation

Summary Introduction

a.

To determine:

The phrase that describes “basal factors” among the options given below.

1. organizes enhancer/promoter interactions

2. pattern of expression depends on which parent transmitted the allele

3. activates gene transcription temporal- and tissue-specifically

4. site of DNA methylation

5. identifies DNA-binding sites of transcription factors

6. bind to enhancers

7. bind to promoters

8. bind to activators

9. prevents or reduces gene expression posttranscriptionally

10. heritable change in gene expression not caused by DNA sequence mutation

Introduction:

Basal transcription factors are a group of general transcription factors that play a key role in the process of transcription.

Answer to Problem 1P

Correct answer:

Basal factors: Bind to promoters

Explanation of Solution

Basal factors are classified as sequence specific proteins. These factors bind to the promoters and influences the process of transcription.

Summary Introduction

b.

To determine:

The phrase that describes “repressors” among the options given below.

1. organizes enhancer/promoter interactions

2. pattern of expression depends on which parent transmitted the allele

3. activates gene transcription temporal- and tissue-specifically

4. site of DNA methylation

5. identifies DNA-binding sites of transcription factors

6. bind to enhancers

7. bind to promoters

8. bind to activators

9. prevents or reduces gene expression posttranscriptionally

10. heritable change in gene expression not caused by DNA sequence mutation

Introduction:

Repressors are a type of transcription factors that bind to enhancers and inhibit the process of transcription.

Answer to Problem 1P

Correct answer:

Repressors: Bind to enhancers

Explanation of Solution

Repressors are the transcription factors present in eukaryotes. They bind to the enhancers and prevent transcription initiation.

Summary Introduction

c.

To determine:

The phrase that describes “CpG” among the options given below.

1. organizes enhancer/promoter interactions

2. pattern of expression depends on which parent transmitted the allele

3. activates gene transcription temporal- and tissue-specifically

4. site of DNA methylation

5. identifies DNA-binding sites of transcription factors

6. bind to enhancers

7. bind to promoters

8. bind to activators

9. prevents or reduces gene expression posttranscriptionally

10. heritable change in gene expression not caused by DNA sequence mutation

Introduction:

Almost 70 to 80% of cytosines present in CpG islands are methylated. The process of mehtlyation incase of CpG islands is mediated by DNA methyltransferase.

Answer to Problem 1P

Correct answer:

CpG: Site of DNA methylation

Explanation of Solution

CpG dinucleotide is the site of methylation. Here the methyl group is added at the 5^th carbon of the cytosine base on one strand of double helix DNA.

Summary Introduction

d.

To determine:

The phrase that describes “imprinting” among the options given below.

1. organizes enhancer/promoter interactions

2. pattern of expression depends on which parent transmitted the allele

3. activates gene transcription temporal- and tissue-specifically

4. site of DNA methylation

5. identifies DNA-binding sites of transcription factors

6. bind to enhancers

7. bind to promoters

8. bind to activators

9. prevents or reduces gene expression posttranscriptionally

10. heritable change in gene expression not caused by DNA sequence mutation

Introduction:

Impriting is the term that is majorily concerned with the branch of biology called epigenetics.

Answer to Problem 1P

Correct answer:

Imprinting: Pattern of expression depends on which parent transmitted the allele

Explanation of Solution

Genome imprinting is an epigenetic phenomenon in which allele expression depends on the parent that transmits it. In this phenomenon, the copy of the gene from one parent remains transcriptionally inactive, whereas the copy of the gene from other parent remains active.

Summary Introduction

e.

To determine:

The phrase that describes “miRNA” among the options given below.

1. organizes enhancer/promoter interactions

2. pattern of expression depends on which parent transmitted the allele

3. activates gene transcription temporal- and tissue-specifically

4. site of DNA methylation

5. identifies DNA-binding sites of transcription factors

6. bind to enhancers

7. bind to promoters

8. bind to activators

9. prevents or reduces gene expression posttranscriptionally

10. heritable change in gene expression not caused by DNA sequence mutation

Introduction:

miRNA or microRNA play a significant role in the process of post transcriptional gene silencing and gene regulation.

Answer to Problem 1P

Correct answer:

miRNA: Prevents or reduces gene expression posttranscriptionally

Explanation of Solution

The miRNAs are the negative regulators of target mRNAs. As a result, they block the translation of mRNA and destabilizes it.

Summary Introduction

f.

To determine:

The phrase that describes “coactivators” among the options given below.

1. organizes enhancer/promoter interactions

2. pattern of expression depends on which parent transmitted the allele

3. activates gene transcription temporal- and tissue-specifically

4. site of DNA methylation

5. identifies DNA-binding sites of transcription factors

6. bind to enhancers

7. bind to promoters

8. bind to activators

9. prevents or reduces gene expression posttranscriptionally

10. heritable change in gene expression not caused by DNA sequence mutation

Introduction:

Coactivator functions as a regulator and bind to activators to enhance the process of transcription.

Answer to Problem 1P

Correct answer:

Coactivators: Bind to activators

Explanation of Solution

Coactivators are the proteins that bind to the activators and open chromatin structure for gene transcription.

Summary Introduction

g.

To determine:

The phrase that describes “epigenetic effect” among the options given below.

1. organizes enhancer/promoter interactions

2. pattern of expression depends on which parent transmitted the allele

3. activates gene transcription temporal- and tissue-specifically

4. site of DNA methylation

5. identifies DNA-binding sites of transcription factors

6. bind to enhancers

7. bind to promoters

8. bind to activators

9. prevents or reduces gene expression posttranscriptionally

10. heritable change in gene expression not caused by DNA sequence mutation

Introduction:

Epigentics deals with changes in the expression of the gene and epigenetic effect does not involve the role underlying DNA sequence.

Answer to Problem 1P

Correct answer:

Epigenetic effect: Heritable change in gene expression not caused by DNA sequence mutation.

Explanation of Solution

The epigenetic effect is observed in mammals especially in humans. It is the phenomenon in which the base sequence of DNA does not change. DNA methylation is responsible for altering the gene expression.

Summary Introduction

h.

To determine:

The phrase that describes “insulator” among the options given below.

1. organizes enhancer/promoter interactions

2. pattern of expression depends on which parent transmitted the allele

3. activates gene transcription temporal- and tissue-specifically

4. site of DNA methylation

5. identifies DNA-binding sites of transcription factors

6. bind to enhancers

7. bind to promoters

8. bind to activators

9. prevents or reduces gene expression posttranscriptionally

10. heritable change in gene expression not caused by DNA sequence mutation

Introduction:

Insulators function as sites for the binding of specific DNA binding proteins. These insulators may function as enhancer blocker.

Answer to Problem 1P

Correct answer:

Insulator: Organizes enhancer/promoter interactions.

Explanation of Solution

Insulators are the DNA elements which help in the interaction of enhancer and a promoter that are present in the same loop. Insulators are the elements of DNA which form a loop from chromatin.

Summary Introduction

i.

To determine:

To determine:

The phrase that describes “enhancer” among the options given below.

1. organizes enhancer/promoter interactions

2. pattern of expression depends on which parent transmitted the allele

3. activates gene transcription temporal- and tissue-specifically

4. site of DNA methylation

5. identifies DNA-binding sites of transcription factors

6. bind to enhancers

7. bind to promoters

8. bind to activators

9. prevents or reduces gene expression posttranscriptionally

10. heritable change in gene expression not caused by DNA sequence mutation

Introduction:

Enhancers are specific region of DNA which increase the rate of transcription of a specific gene.

Answer to Problem 1P

Correct answer:

Enhancer: Activates gene transcription temporal-and tissue-specifically

Explanation of Solution

Enhancers are cis-acting sequences which control the gene regulation and have many binding sites for different activators and repressors. Therefore, they are responsible for tissue and temporal specific gene transcription.

Summary Introduction

j.

To determine:

The phrase that describes “Chip-Seq” among the options given below.

1. organizes enhancer/promoter interactions

2. pattern of expression depends on which parent transmitted the allele

3. activates gene transcription temporal- and tissue-specifically

4. site of DNA methylation

5. identifies DNA-binding sites of transcription factors

6. bind to enhancers

7. bind to promoters

8. bind to activators

9. prevents or reduces gene expression posttranscriptionally

10. heritable change in gene expression not caused by DNA sequence mutation

Introduction:

Chip-Seq is sequencing methodology that can be used to determine the presence of transcription factors in the genome.

Answer to Problem 1P

Correct answer:

ChIP-Seq: Identifies DNA-binding sites of transcription factors

Explanation of Solution

Chromatin immunoprecipitation sequencing (ChIP-Seq) is a technique which helps in the identification of target genes belonging to a specific transcription factor. The specific antibody identifies the target gene that regulates specific transcription factors.