Molecular Biology 2nd Edition by
David P. Clark
Complete Chapter Solutions Manual
are included (Ch 1 to 26)
** Immediate Download
** Swift Response
** All Chapters included
,Table of Contents are given below
Chapter 1 - Cells and Organisms
Chapter 2 - Basic Genetics
Chapter 3 - DNA, RNA, and Protein
Chapter 4 - Genomes and DNA
Chapter 5 - Manipulation of Nucleic Acids
Chapter 6 - Polymerase Chain Reaction
Chapter 7 - Cloning Genes for Analysis
Chapter 8 - DNA Sequencing
Chapter 9 - Genomics & Systems Biology
Chapter 10 - Cell Division and DNA Replication
Chapter 11 - Transcription of Genes
Chapter 12 - Processing of RNA
Chapter 13 - Protein Synthesis
Chapter 14 - Protein Structure and Function
Chapter 15 - Proteomics: The Global Analysis of Proteins
Chapter 16 - Regulation of Transcription in Prokaryotes
Chapter 17 - Regulation of Transcription in Eukaryotes
Chapter 18 - Regulation at the RNA Level
Chapter 19 - Analysis of Gene Expression
Chapter 20 - Plasmids
Chapter 21 - Viruses
Chapter 22 - Mobile DNA
Chapter 23 - Mutations and Repair
Chapter 24 - Recombination
Chapter 25 - Bacterial Genetics
Chapter 26 - Molecular Evolution
,Chapter 1
Review Questions Answers
1. Life is difficult to define. There is no one definition of what is living that is suitable to all
organisms. There are some characteristics that are used to help identify living organisms.
These characteristic include growth and reproduction (at least at some point in existence),
possession of genetic information, mechanisms for energy generation, the ability to
synthesize new cellular components using chemical machinery, being made of cells, an
identity of self, and the ability to adapt to the environment.
2. The cell is the basic unit of life. In multicellular organisms, cells often differentiate into
specialized cells, such as a cardiac muscle cell, red blood cell, liver cell, etc.
3. The cell membrane separates the inside and outside environments of the cell and allows the
cell to maintain different conditions on the inside from the conditions present in the external
environment. The cell membrane is also called a phospholipid bilayer because it is made of
two layers of phospholipids and embedded with several proteins. The phospholipids each
have a hydrophilic “head” and two hydrophobic “tails”. In the presence of water, these lipids
arrange themselves so that the “heads” are in contact with the water of the cytoplasm and
external environment and the two fatty acid hydrophobic “tails” are protected from water.
The membrane is very flexible and forms a selectively-permeable barrier. The bilayer only
allows certain molecules to pass, usually only hydrophobic molecules can diffuse across the
membrane unaided. The proteins in the lipid bilayer serve various roles from transporting
hydrophilic or larger molecules, to catalyzing some of the reactions in respiration or
photosynthesis.
4. Ribosomes are cellular machines that translate the information on messenger RNA (mRNA)
into polypeptides. Ribosomes are located within the cytoplasm of all cell types. In higher
organisms (eukaryotes), ribosomes may also be anchored to a membranous subcellular
component called the rough endoplasmic reticulum.
5. Prokaryotes and eukaryotes are divided based upon subcellular compartmentalization.
Prokaryotes are simpler organisms that lack membrane-bound organelles, the largest of
which is the nucleus. Eukaryotes are more complicated and compartmentalize into various
subcellular organelles that are membrane-bound. Quite simply, prokaryotes do not have a
nucleus and eukaryotes do have a nucleus, as well as many other membrane-bound
organelles. Despite the differences, all cells have some general features in common. These
features include the presence of genetic information, a plasma membrane, cytoplasm, and
ribosomes.
6. Eubacteria and archaebacteria (archaea) are two distinct groups of prokaryotes. Despite the
fact they are both prokaryotes, they are not genetically related to each other. Since they are
both prokaryotic, they lack a nucleus and other membrane-bound organelles. In terms of gene
expression, the machinery used for such processes as transcription and translation in archaea
resemble the eukaryotic machinery. The phospholipid bilayer is also different between
archaea and eubacteria. The linkage of the fatty acid “tails” to the “head” portion of a
phospholipid is different between the two groups. Additionally, the cell walls of eubacteria
always contain peptidoglycan. Archaea also have cells walls made of a variety of materials.
Peptidoglycan is not one of them.
, 7. Bacteria are widely used to study cell function because they are single-celled microorganisms
that reproduce asexually, which means all the cells in the bacterial cultures are identical.
Bacteria are also used because they have small numbers of genes compared to higher
organisms. Bacterial genomes are haploid, having only a single copy of the chromosome,
which makes analyzing genes easier. Plasmids are often present in bacterial genomes, which
are useful for carrying extra genes for study. Bacteria are easy to grow in a wide variety of
conditions and even grown very quickly, some dividing in as little as 20 minutes. A single
bacterial culture contains billions of cells, so large numbers of identical cells can be analyzed
at the same time. Bacteria are easy to store for extended period of times, even years. The
model bacterial organism often used in research is Escherichia coli, which is found in the
mammalian colon.
8. The eukaryotic nucleus is surrounded by a double membrane called the nuclear envelope.
The nuclear envelope has tiny nuclear pores to allow communication between the nucleus
and cytoplasm.
9. Organelles are subcellular structures designed for a specific function within eukaryotic cells.
Some organelles include the endoplasmic reticulum (smooth and rough), Gogli apparatus,
lyososomes, mitochondria, and chloroplasts. The endoplasmic reticulum (ER) is membranous
and continuous with the nuclear envelope. The endoplasmic reticulum as two varieties, rough
and smooth. The rough ER contains ribosomes and is partly responsible for the synthesis of
some proteins. The smooth ER has many functions, some of which include calcium storage
and detoxification of harmful substances. The Golgi apparatus is a stack of flattened
membranous stacks and functions to secrete proteins or other substances outside of the cell.
Lysosomes are membrane-bound organelles that contain digestive enzymes. They degrade
food substances and malfunctioning or deformed organelles. The reactions of cellular
respiration occur within the mitochondria. Mitochondria are the powerhouses of cells
because they convert the energy in food substance into a more usable form, usually
adenosine triphosphate (ATP). Chloroplasts are also membrane-bound organelles that are
used to capture sunlight energy for photosynthesis. Chloroplasts are found only in
photosynthetic eukaryotes.
10. Domain Eukarya; Kingdom Animalia; Phylum Chordata (subphylum vertebrata); Class
Mammalia; Order Primates; Family Hominidae; Genus Homo; Species sapiens.
11. Saccharomyces cerevisiae is a single-celled yeast (eukaryote) that is often used as a model
organism in molecular biology for many of the same reasons that bacteria are used (See
Number 7). The life cycle of this yeast alternates between a diploid and a haploid phase. The
haploid yeast have only a single copy of each gene, which makes the isolation of mutations
and analysis of gene function easier. In the diploid phase, the interaction of two alleles for a
gene can be studied within the same cell.
12. Roundworms, Caenorhabditis elegans, are useful for studying multicellular animals because
the lineage of each cell in the roundworm (959 cells to be exact) can be traced from the
fertilized egg. This knowledge is used then to study animal development. In addition to C.
elegans, Drosophila melanogaster, a fruit fly, is often used to study cell differentiation,
development, signal transduction, and behavior in multicellular animals.
13. Danio rerio (zebrafish) is used to study the genetic effects in vertebrate development.
Because the fish are transparent, the development of internal organs can be observed.
Additionally, zebrafish are now being used in the initial screening of drugs for toxicity.
