bartleby

Concept explainers

bartleby

Videos

Textbook Question
Book Icon
Chapter 21, Problem 1NST

In a sequence encompassing 99.4 percent of the euchromatic regions of human chromosome 1, Gregory et al. [(2006) Nature 441:315–321] identified 3141 genes.

  1. (a) How does one identify a gene within a raw sequence of bases in DNA?
  2. (b) What features of a genome are used to verify likely gene assignments?
  3. (c) Given that chromosome 1 contains approximately 8 percent of the human genome, and assuming that there are approximately 20,000 genes, would you consider chromosome 1 to be “gene rich”?

(a)

Expert Solution
Check Mark
Summary Introduction

To determine: The ways by which an individual can identify a gene within a raw sequence of bases in DNA.

Introduction: The bioinformatics includes the use of computer hardware and software, mathematics applications to organize, share and analyze data that is related to gene structure, gene sequence and expression; and protein structure and function.

Explanation of Solution

To annotate a gene, an individual identifies gene-regulatory sequences such as promoters, enhancers, and silencers that are found upstream of genes. A person can also identify downstream elements such as termination sequences and in-frame triplet nucleotides that are part of the coding region of the gene. Moreover, 5’ and 3’ splice sites are also used. These splice sites distinguish exons from introns. The polyadenylation sites can also be used in annotation.

Thus, a person can identify a gene from the raw sequence of bases by identifying gene-regulatory sequences and the downstream elements.

(b)

Expert Solution
Check Mark
Summary Introduction

To determine: The characteristics of a genome which are used to verify similar gene assignment.

Introduction: Gene is a unit of DNA that is present on a chromosome. It controls the development of one or more traits. The gene is the basic unit through which genetic information is passed from parent to offspring.

Explanation of Solution

The similarity to other annotated sequences provides an approach to a sequence’s functions, and it confirms a particular genetic assignment. Direct sequencing of cDNAs from various tissues and developmental stages aids in verification.

Thus, direct sequencing of cDNAs of a genome is used to verify similar gene assignment.

(c)

Expert Solution
Check Mark
Summary Introduction

To determine: Whether the chromosome 1 will be considered as “gene rich” provided that it contains approximately 8 % of the human genome and 20,000 genes.

Introduction: The human genome is referred to as the genome of Homo sapiens. The human genome consists of 23 pairs of the chromosome with a total of about 3 billion DNA base pairs.

Explanation of Solution

The 3141 genes identified on chromosome 1which constitute 15.7 % of the total number of genes in the human genome (estimated to be 20,000). As per the given information, chromosome 1 contains 8 % of the human genome and nearly 16 % of the genes; one can say that chromosome 1 is “gene rich”.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!
Students have asked these similar questions
If the bandicoot genome is 3.62 x 109 base pairs, and the "highly repetitive DNA" fraction is composed entirely of copies of sequence 5'TGCGTGTGTGC3' and its complement, how many copies of this sequence are present in the bandicoot genome?
At the end of the short arm of human chromosome 16 (16p), several genes associated with disease are present, including thalassemia and polycystic kidney disease. When that region of chromosome 16 was sequenced, gene-coding regions were found to be very close to the telomere-associated sequences. Could there be a possible link between the location of these genes and the presence of the telomere-associated sequences? What further information concerning the disease genes would be useful in your analysis?
Although DNA transposons are abundant in the genomes of multicellular eukaryotes, class 1 elements usually make up the largest fraction of very large genomes such as those from humans (~2500 Mb), maize (~2500 Mb), and barley (~5000 Mb). Given what you know about class 1 and class 2 elements, what is it about their distinct mechanisms of transposition that would account for this consistent difference in abundance?

Chapter 21 Solutions

Concepts Of Genetics, Books A La Carte Edition; Modified Masteringgenetics With Pearson Etext -- Valuepack Access Card -- For Concepts Of Genetics (11th Edition)

Knowledge Booster
Background pattern image
Biology
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biology and related others by exploring similar questions and additional content below.
Similar questions
SEE MORE QUESTIONS
Recommended textbooks for you
Text book image
Biology: The Dynamic Science (MindTap Course List)
Biology
ISBN:9781305389892
Author:Peter J. Russell, Paul E. Hertz, Beverly McMillan
Publisher:Cengage Learning
Genome Annotation, Sequence Conventions and Reading Frames; Author: Loren Launen;https://www.youtube.com/watch?v=MWvYgGyqVys;License: Standard Youtube License