Advances in Genetics #101

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1 Questions: Five study Questions EQ1: What are 3 ways of producing organisms with desired traits? EQ2: What are 2 applications of DNA technology in human genetics? Like your fingerprints, your DNA is different from everyone else s. DNA evidence can show many things, including family relationships. Selective Breeding Genetic techniques have enabled people to produce organisms with desirable traits : Selective breeding, cloning, and genetic engineering are three methods for developing organisms with desirable traits. Selective Breeding The process of selecting organisms with desired traits to be parents of the next generation EXAMPLE: Corn Thousands of years ago, every year farmers saved seeds from the healthiest plants that produced the best corn and planted those seeds in the spring. They repeated this for many years and eventually they were growing better corn. Selective breeding has been used with many plants and animals There are 2 types of selective breeding 1. Inbreeding 2. hybridization

2 Inbreeding Hybridization Advances in Genetics #101 Inbreeding The technique that involves crossing 2 individuals that have similar characteristics EXAMPLE: Turkeys male and female turkeys that are both plump and grow fast will likely produce offspring that also have those traits inbred organisms are genetically very similar to each other and their parents inbreeding produces desired traits but also increases the chance that organisms inherit genetic disorders Hybridization The technique where breeders cross 2 genetically different individuals the hybrid organism that results is bred to have the best traits from both parents EXAMPLE: Corn a farmer might cross corn that produces many kernels with corn that is resistant to disease. The result might be a hybrid corn plant with both of these desired traits. Can you think of another example of a food that might be a hybrid? Cloning For some organisms, cloning can be used to produce offspring with desired traits Clone An organism that has exactly the same genes as the organism from which it was produced

3 EXAMPLE: Some plants are easy to clone cut a stem from one plant, put it in soil, water it and it will grow a new plant. The new plant is genetically identical to the plant the stem originally came from. Cloning animals is more complex EXAMPLE: sheep and pigs have been cloned take the nucleus of an animal s body cell and use it to produce a new animal Genetic Engineering Genetic Engineering Another technique used to produce desirable traits in organisms When genes from one organism are transferred into the DNA of another organism EXAMPLE: this technique is used to produce medicines and improved food crops Genetic Engineering in Bacteria One type of genetically engineered bacteria produces insulin the protein needed to regulate blood sugar. Diabetics need to take insulin injections because they typically do not produce enough of their own insulin. Scientists use genetic engineering to create bacterial cells that produce important human proteins such as insulin

4 Genetic Engineering in Other Organisms Scientists can also insert genes into animals EXAMPLE: Cows human genes can be inserted into the cells of cows and the cows then produce the human protein in their milk (scientists used this to produce a blood clotting protein for people with hemophilia) Scientists can insert genes into plants for beneficial reasons EXAMPLE: Tomatoes and Rice genes have been inserted into these plants to enable them to survive in cold temperatures, poor soil, and resist insect pests Gene Therapy Gene Therapy Scientists hope to someday use genetic engineering to correct some genetic disorders A process involving inserting copies of a gene directly into a person s cells.

5 Concerns About Genetic Engineering Some people think genetically engineered crops may not be safe fear they may harm environment or cause health problems in humans Scientists do not have all the answers and are trying to learn more about the effects of genetic engineering Learning About Human Genetics : Applications of DNA technology include studying the human genome in detail and identifying people Genome The Human Genome Project All the DNA in one cell of an organism The goal of the Human Genome Project is to identify the DNA sequence of every gene in the human genome DNA of humans has at least 30,000 genes The average gene has 3,000 bases Scientists now know the DNA sequence of nearly every human gene DNA Fingerprinting DNA technology can also identify people and show whether people are related DNA from the nucleus is broken into small pieces and used to make a pattern called a DNA fingerprint Nobody has the exact same DNA fingerprint EXCEPT identical twins

6 Mitochondria has its own DNA which can also be used to identify people Mitochondria is passed down from the mother s egg cell (when the egg and sperm fuse to make the daughter cell, the mitochondria comes from the egg) This means that a child has virtually the same mitochondrial DNA as his or her mother, making it possible to trace inheritance from grandmothers to grandchildren Summary: 5 sentence paragraph that includes the answers to the EQ