Pierce’s Genetics: Chapter 1

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What does heredity do to human life?
Heredity affects many of our physical features as well as our susceptibility to many diseases and disorders. Genetics contributes to advances in agriculture, pharmaceuticals, and medicine and is fundamental to modern biology. All organisms use similar genetic systems, and genetic variation is the foundation of the diversity of all life.
What are some of the implications of all organisms having similar
genetic systems?
a. That all life forms are genetically related
b. That research findings on one organism’s gene function can often
be applied to other organisms
c. That genes from one organism can often exist and thrive in
another organism
d. All of the above
d. All of the above
What are the three divisions of genetics?
The three major divisions of genetics are transmission genetics,
molecular genetics, and population genetics. Transmission genetics
examines the principles of heredity; molecular genetics deals
with the gene and the cellular processes by which genetic information
is transferred and expressed; population genetics concerns
the genetic composition of groups of organisms and how that
composition changes over time and geographic space. Model
genetic organisms are species that have received special emphasis
in genetic research; they have characteristics that make them useful
for genetic analysis.
Would the horse make a good model genetic organism? Why or why not?
No, because horses are expensive to house, feed, and
propagate, they have too few progeny, and their generation time
is too long.
What is the first application of genetics?
Humans first applied genetics to the domestication of plants and
animals between approximately 10,000 and 12,000 years ago.This
domestication led to the development of agriculture and fixed
human settlements.
What is the foundation of genetics?
Developments in plant hybridization and cytology in the eighteenth
and nineteenth centuries laid the foundation for the field
of genetics today. After Mendel’s work was rediscovered in 1900,
the science of genetics developed rapidly and today is one of the
most active areas of science.
How did developments in cytology in the nineteenth century
contribute to our modern understanding of genetics?
Developments in cytology in the 1800s led to the
identification of parts of the cell, including the cell nucleus and
chromosomes. The cell theory focused the attention of biologists
on the cell, which eventually led to the conclusion that the
nucleus contains the hereditary information
A complete set of genetic instructions for any organism
transmission genetics
Transmission genetics is also known as classical genetics, transmission genetics encompasses the basic principles of heredity and how traits are passed from one generation to the next.
molecular genetics
Molecular genetics concerns the chemical nature of the
gene itself: how genetic information is encoded, replicated,
and expressed
population genetics
Population genetics explores the genetic composition
of groups of individual members of the same species (populations)
and how that composition changes over time and
geographic space
Model genetic organisms
organisms having characteristics that make
them particularly useful for genetic analysis and about which
a tremendous amount of genetic information has accumulated
The ancient Greeks gave careful consideration to human
reproduction and heredity. The dissection of animals by the
Greek physician Alcmaeon (circa 520 B.C.) sparked a long
philosophical debate about where semen was produced that
culminated in the concept of pangenesis.
inheritance of acquired characteristics
Pangenesis led the ancient Greeks to propose the notion of the inheritance of acquired characteristics, in which traits acquired in one’s lifetime become incorporated into one’s hereditary information and are passed on to offspring; for example, people who
developed musical ability through diligent study would produce children who are innately endowed with musical ability. Although incorrect, these ideas persisted through the twentieth century.
Preformationism meant that all traits would be inherited from only one parent—from the father if the homunculus was in the sperm or from the mother if it was in the egg. According to preformationism, inside the egg or sperm there exists a tiny miniature adult, a homunculus, which simply enlarges during development
blending inheritance
blending inheritance,
which proposed that offspring are a blend, or mixture,
of parental traits. This idea suggested that the genetic material
itself blends,much as blue and yellow pigments blend to
make green paint. Once blended, genetic differences could
not be separated out in future generations, just as green paint
cannot be separated out into blue and yellow pigments.
Some traits do appear to exhibit blending inheritance; however,
thanks to Gregor Mendel’s research with pea plants, we
now understand that individual genes do not blend.
cell theory
all life is
Introduction to Genetics 9
composed of cells, cells arise only from preexisting cells, and
the cell is the fundamental unit of structure and function in
living organisms. Biologists began to examine cells to see
how traits were transmitted in the course of cell division.
germ-plasm theory
the germ-plasm theory, which holds
that the cells in the reproductive organs carry a complete
set of genetic information that is passed to the egg and
What role does genetics play in life of every person?
Genetics is central to the life of every person: it influences a
person’s physical features, susceptibility to numerous diseases,
personality, and intelligence.
What role does genetics play in other aspects of life?
Genetics plays important roles in agriculture, the
pharmaceutical industry, and medicine. It is central to the
study of biology
What is the foundation of evolution?
All organisms use similar genetic systems. Genetic variation is
the foundation of evolution and is critical to understanding all
What are the divisions of the study of genetics?
The study of genetics can be divided into transmission
genetics, molecular genetics, and population genetics
What are model genetic organisms?
Model genetic organisms are species having characteristics
that make them particularly amenable to genetic analysis and
about which much genetic information exists.
What did the use of genetics begin?
The use of genetics by humans began with the domestication
of plants and animals.
Who developed the concepts of pangenesis?
The ancient Greeks developed the concepts of pangenesis and
the inheritance of acquired characteristic
What is preformationism?
Preformationism suggested that a person inherits all of his or
her traits from one parent. Blending inheritance proposed that
offspring possess a mixture of the parental traits.
How did Gregor Mendel discovered the principles of heredity?
By studying the offspring of crosses between varieties of peas,
Gregor Mendel discovered the principles of heredity.
Developments in cytology in the nineteenth century led to the
understanding that the cell nucleus is the site of heredity
What were Mendel’s principles of heredity rediscovered?
In 1900, Mendel’s principles of heredity were rediscovered.
Population genetics was established in the early 1930s, followed
closely by biochemical genetics and bacterial and viral
genetics. The structure of DNA was discovered in 1953,
stimulating the rise of molecular genetics
What are the basic types of cells?
Cells are of two basic types: prokaryotic and eukaryotic
What is genotype and phenotype?
The genes that determine a trait are termed the genotype; the
trait that they produce is the phenotype
What are genes located?
Genes are located on chromosomes, which are made up of
nucleic acids and proteins and are partitioned into daughter
cells through the process of mitosis or meiosis.
How is genetic information expressed?
Genetic information is expressed through the transfer of
information from DNA to RNA to proteins
What does evolution require?
Evolution requires genetic change in populations
Categories: Genetics