What Are Multiple Alleles
What are multiple alleles?
/ Multiple alleles are three or more forms of a single gene (The ABO blood group gene has multiple alleles.)What are polygenetic traits?
/ Single traits that are produced by multiple genes acting together (Eye color, hair color, and height are examples of polygenetic traits.)What factors might influence the expression of a gene? / Traits are often influenced by environmental factors such as include diet, disease, etc.)
What are the sex chromosomes?
/ The X & Y chromosomes are called the sex chromosomes. Among other things they code for the production of hormones that make males - males and females – females. In humans the sex chromosomes are the 23rd pair.What are the sex chromosomes for a male?
/ Males have one X & one Y chromosome. (XY)
What are the sex chromosomes for a female? / Females have two X chromosomes. (XX)
What is a sex-linked trait? / A sex-linked trait is a condition caused by a defective gene on the X chromosome that has no homologous (the same) gene on the Y chromosome to override it.
What is special about a pedigree chart used by geneticists? / A pedigree chart used by geneticists shows the pattern of inheritance of a particular trait through a number of generations of a family.
What is a genetic disorder? / A genetic disorder is an abnormal condition caused by a mutation, a change in a organism’s DNA in a gene or a chromosome. (There are several kinds of mutations.)
Can genetic disorders be inherited? / Some genetic disorders like cystic fibrosis, and sickle-cell anemia can be inherited.
What is amniocentesis? / Amniocentesis is a test used to diagnose genetic disorders before a baby is born.
What is the procedure for amniocentesis? / During amniocentesis a small amount of fluid (amniotic fluid) from around the developing fetus is extracted using a syringe. Fetal cells from the fluid are analyzed to see if there are any chromosomal abnormalities.
What is karyotyping? / Karyotyping is a tool used by geneticists to discover genetic disorders. A sample of genetic material is taken from a white blood cell. The chromosomes are isolated, organized in pairs, photographed and studied.
What does a genetic counselor do? / Genetic counselors help couples understand their chances of having a child with a genetic disorder.
What is selective breeding? / Selective breeding is the process of selecting a few organisms with desired traits to serve as parents for the next generation of organisms.
Why has selective breeding been practiced by farmers and animal breeders? / Farmers and animal breeders have used selective breeding to improve domesticated plants and animals for thousands of years.
What is cloning? / Cloning is a technique used to produce an organism that is genetically identical to the organism from which it was produced.
What is the procedure for cloning an organism? / Cloning involves removing a nucleus from an egg cell, replacing it with the nucleus of the organism to be cloned, and placing the egg cell with its new nucleus into a compatible or the same female for gestation.
What is genetic engineering?
/ Genetic engineering involves the transfer of a gene from the DNA of one organism to the DNA of another organism.How is genetic engineering used? / Genetic engineering can be used to produce medicines like insulin and to improve food crops like tomatoes, which can withstand cold temperatures.
What is gene therapy? / Gene therapy involves the insertion of working copies of a gene into the cells of a person with a genetic disorder in an attempt to correct the disorder.
What is DNA fingerprinting / DNA fingerprinting involves extracting DNA from bodily fluids, hair, and/or skin and using it to create a pattern of images of DNA sequences that are unique to every individual except for identical twins.
Why is DNA fingerprinting used? / DNA fingerprints can determine if a particular suspect was at a crime scene.
What is the Human Genome Project? / The goal of the Human Genome Project was to identify the DNA sequence of every gene on every chromosome in a human cell (a genome).
What was the importance of sequencing the genes in a human genome? / Scientists feel that the identification of all human genes will lead to understanding diseases and discovering their cures.