KEY Name: Period: ______________ Biology: Genetic Technology questions (revised 11/2015 1. Selective breeding has been used for at least 2,000 years. What job (career) do you think the first breeders had? Farmers 2. Besides being gross, marrying close relatives is illegal in the United States. Since rare recessive genes control most deadly diseases, explain how this law helps protect the health of future generations. Reduces the chances of two recessive alleles coming together to produce disorders. 3. Mutts (non purebred) dogs from an animal shelter often make great pets because they generally live long, healthy lives. What would a geneticist call a “mutt” and how would they explain its health. Mutts to a geneticist are “hybrids”. The health and strong growth of most hybrids is referred to as “hybrid vigor”. 4. Compare and contrast selective breeding and genetic engineering. Both are used to change traits of organisms. Selective breeding tries to make organisms “purebred” for the trait, in other words make a trait that is already present in some individuals the more common version of the trait. Genetic engineering usually targets a specific gene, and can even take genes (and therefore a trait) from a different type of organism. 5. DNA must be cut to change its genes. But DNA is way too small to cut even with a laser. What is used to cut DNA? Restriction enzymes 6. What is a transgenic organism? An organism with functional DNA in it obtained from a different organism 7. Both mechanical and biological types of DNA vectors are useful. What is the benefit of each? Mechanical provides more control over which cells get the new gene, biological uses a natural process that incorporates the gene into the host’s DNA. Biological shows more promise of working in a whole organism as opposed to cells in a laboratory. 8. How is reproductive cloning achieved? (list as steps). 1. 2. 3. 4. Obtain a 2n donor cell. Fresh, new cells such as skin cells work best. Get a donor egg cell. Remove nucleus from egg (enucleate). Put DNA from 2n donor cell into egg. Plant “fertilized” egg in womb of surrogate mother. 9. Why is reproductive cloning being mostly abandoned by genetic researchers? Poor success rate and lots of birth defects. 10. List and defend two current or future uses of recombinant DNA/transgenic organisms that you think will benefit the world’s populations the most. Why do you think so? (think global, not just Southington!) Lots of choices. Rice with protein in it is already being grown in some areas of the world to provide more nutrition to people where meat is not common or available in the diet. Bt corn is pest resistant, requiring far less pesticide use. 11. How many genes are believed to be in the entire human genome? 20,000 – 25,000 (current best estimate is around 22,400) 12. How is it possible that the number of genes is far less than the ~100,000 proteins known in humans? The same sequence is edited into different combinations after transcription 13. How much of the human genome codes for proteins? only 1.5% a. What is the nickname for non-coding part and what is its main function? The rest is called “junk” but now known to code for some gene expression control genes. 14. What discovery/invention allowed the human genome project and most of the current research into the molecular basis of genetics to be possible? Polymerase chain reaction (PCR.) This technology replicates or clones samples of DNA to allow research to be done on it. 15. Describe gene editing and one treatment that has been created by editing genes. Gene editing is using engineered restriction enzymes to specifically remove and then sometimes replace genes. Used to edit T-cells to attack leukemia, used to remove proteins from pig organs to reduce rejection when they are given as donor organs. 16. What use for microRNA (miRNA) has been discovered? To silence genes and stopping them from producing a protein without having to remove or repair the gene. 17. List and describe the three types of stem cells. Embryonic (pluripotent) stem cells are any purpose cells, Adult (multipotent) stem cells are limited to some cell lines and types, but are useful blood cell disease treatments. Induced pluripotent stem cells are somatic cells reversed back to being "anything"cells. 18. What is the great bioethical benefit of induced pluripotent stem cells (iPSCs)? iPSCs do not require the sacrifice of embryos for the collection of stem cells.