Genetics 303 Ch 1

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How does genetics influence our lives?
Affect our height, weight, hair color, pigmentation, and susceptibility to diseases and disorders. Contribute to our intelligence and personality.
What is a gene?
Unit of heredity; coded/noncoded information in DNA.
Is genetics a new field of study?
Yes and No .People have understood the hereditary nature of traits an practiced genetics for THOUSANDS of years.
What is Genetics?
Genetics is the scientific study of heredity that determines how traits and diseases are passed from generation to generation.
Examines the molecules that comprise genes and how genes are regulated (i.e., turned on and off) . Many specialized fields within “Genetics”: Population Genetics and Biotechnology. It’s a broad field because it is the key to all biology.
Is it possible to avoid eating foods containing genetically modified organisms (GMO’s)?
No, its impossible to avoid genetically modified foods.
Science + Ethics + Law = Genetics
Genetics and the application of its technologies give rise to issues of privacy, ethics, and legality .Scientists, physicians, politicians, and others constantly debate the fate of genetic information and the legality of its use—and misuse. Addressing the legal, ethical, and social questions associated with genetics is just as important as the information gained from it. Wrong ideas about genetics have influenced past laws and court decisions; they are still propagated today.
what is DNA?
Deoxyribonucleic acid is the blueprint of life, a string of four types chemical subunits. The order of the four different subunits (the genetic code) encodes information that dictates what each and every cell -the basic unit of life-does.
What controls cellular function and links all organisms?
Four classes of modern genetics:
1. Transmission Genetics
2. Cytogenetics
3. Molecular Genetics
4. Population Gentics
Transmission Genetics
Studies the mechanisms by which traits are passed from parents to offspring.• Geneticists use experimental organisms to study how traits are passed from parents to offspring.For humans, pedigree analysis is used instead of mating experiments. Analysis utilizes detailed family histories to reconstruct the pattern followed by a trait over generations.
studies the organization and arrangement of genes and chromosomes via microscopy. Study of chromosome number and structure using karyotyping, a method to visualize analyze chromosomes.Observations of chromosome behavior placed genes on chromosomes.Currently used to map genes, study chromosome structure, and identify abnormalities
Molecular Genetics
studies genetic events at the biochemical level, has had the greatest impact on human genetics since the early 1980s. Concerns the chemical nature of the gene itself (i.e., how genetic information is encoded, replicated and expressed). It includes the cellular processes of replication, transcription, translation, and—perhaps most importantly—gene expression. Focus is on the gene and its structure, organization and function. Utilizes recombinant DNA technology to identify, isolate, clone, and analyze genes (i.e., genetic engineering). Cloned genes give insight into how genes are organized, how they work, and can be transferred between organisms (e.g., gene therapy) or even species .
Population Gentics
studies the distributions and variation of genes in populations. Inherited variation in populations of individuals and the forces that alter gene frequency. Defines extent of genetic variation within populations.Also explains how migration, population size, natural selection, catastrophic phenomena, etc. affect variation.
What is the relation between genetics and evolution?
Life’s diversity and adaptation are products of evolution, which is simply genetic change through time. Evolution is a two-part process: first, inherited differences arise randomly and, then the proportion of individuals with particular differences increases or decreases. Genetic variation is therefore the foundation of all evolutionary change and its ultimately the basis of all life as we know it.
What are some characteristics of models genetic organisms that make them useful for genetic studies?
All possess life cycles and traits that make them particularly suitable for genetic study, including a short generation time, large but manageable numbers of progeny, adaptability to a laboratory environment, and the ability to be housed and propagated inexpensively.
Would a 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.
Genetics is central to the life of every person:
It influences a person’s physical features, personality, intelligence, and susceptibility to numerous disease. It is central to the study of biology.
Genetics plays important roles in:
agriculture, the pharmaceutical industry, and medicine.
All organism use similar genetic systems? True or False
Genetic variation is the foundation of evolution and is critical to understanding all life? T or F
The study of genetics can be divided into:
transmission genetics,cytogenetics, molecular genetics, population genetics.
What are model genetic organisms?
species about which much genetic information exist because of characteristics that make them particularly amenable to genetic analysis.
How did the use of genetics by humans began?
With domestication of plants and animals.
Why use zebrafish?
Important model in genetic studies because it is a small vertebrate that produces many offspring and is easy to rear in the laboratory
Recessive golden mutant is lighter;
has fewer, smaller and less-dense pigment-containing melanosomes. Lighter skin in humans is similarly due to fewer and less-dense melanosomes in pigmentation-containing cells.
Who is the founder of modern genetics?
Gregor Mendel, first to discovered the principle of heredity by crossing different varieties of pea plants and analyzing the patterns of the transmission of traits in subsequent generations.
Define blending inheritance and contrast with prerfomationism:
Blending inheritance proposed that offspring possess a mixture of the parental traits.
Preformationism suggested that a person inherits all of his of her traits from one parent
Blending inheritance
This idea suggested that the genetic material (parental traits) itself blends, much as blue and yellow pigments blend to make green paint. After having been blended, genetic differences could not be separated in future generations, just as green paint cannot be separated into blue and yellow pigments.
dictated that all traits were derived from ONE parent—contrary to many observations! inside the egg and or sperm there exists a fully formed miniature adult, a homunculus which simply enlarges during development. All traits were inherited from only one parent-from the father if the homunculus was a sperm and from the mother if it was the egg.
Genetic is NOT New
is around ~10,000 years old
The first domesticated organisms included:
wheat, peas, lentils, barley, dogs, goats, and sheep
Artificial selection:
Collected seeds from plants with the most desirable traits and bred only prized animals
Germ-plasm theory:
Ancient farmers preserved seeds, cuttings, etc.; preserved (even traded) genetic stocks
Ancient Greeks like Alcmaeon (alk-mai-ON; c. 520 B.C.) believed in the concept of pangenesis:
According to the pangenesis concept, genetic information from different part of the body, travels to the reproductive organs where its transferred to the gametes (sperm and egg) into the zygote.
Ancient Greeks believed in the inheritance of acquired characteristics;
traits learned during one’s lifetime are passed on to one’s offspring
Categories: Genetics