BIOL 100 Genetics Unit Notes
BIOL 100 Genetics Unit Notes BIOL 100 7012 01
Popular in Biology with Lab
BIOL 100 7012 01
verified elite notetaker
Popular in Biology
verified elite notetaker
This 7 page Class Notes was uploaded by kgrunwaldt on Saturday January 23, 2016. The Class Notes belongs to BIOL 100 7012 01 at Truman State University taught by B Moore in Fall 2015. Since its upload, it has received 26 views. For similar materials see Biology with Lab in Biology at Truman State University.
Reviews for BIOL 100 Genetics Unit Notes
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 01/23/16
1. Genetics: study of patterns of inheritance 2. Inheritance: process by which traits are passed from parents to offspring 3. Genes: discrete units of inheritance (segments of DNA which code for a particular protein) 4. Locus: particular location of a gene on a chromosome (pluralloci) a. Gene pair: two genes at homologous loci 5. Alleles: alternative forms of a gene a. Dominant allele: its effect masks the recessive allele i. Uppercase letter represents a dominant allele ii. Lowercase letter represents a recessive allele b. Homozygous dominant (homozygote) i. Two dominant alleles (AA) c. Homozygous recessive (homozygote) i. Two recessive alleles (aa) d. Heterozygous (homozygous) i. Two different alleles (Aa) “hybrid” 6. Phenotype: observable or expressed traits 7. Genotype: the alleles; the genetic makeup 8. Pea Plant Advantages: a. They can produce several offspring in a short amount of time b. Easy to keep carefully recorded observations 9. Monohybrid cross: dealing with one trait 10. Exceptions a. Incomplete Dominance: phenotype exhibits blended effect (somewhere in between)phenotype is intermediate i. Good examples: snapdragons, carnations b. Codominance: a pair of nonidentical alleles results in the expression of both phenotypes c. Multiple Alleles: more than two alleles in a population that code for a particular trait i. ABO blood typing scheme d. Epistasis: one pair of alleles at one locus may control the expression of another gene pair at a different locususually involves pigment production i. Example: color of labradors, albinism e. Pleiotropy: one pair of genes affects more than one phenotype i. Examples: Marfan syndrome, albinism, sickle cell anemia f. Polygenic Inheritance: more than one pair of genes codes for a trait i. Examples: human skin color, height 11. Cloning a. Reproductive cloning i. Creating genetically identical organisms ii. 2 basic ways to accomplish reproductive cloning: 1. Split cells developing into an embryo 2. Take somatic cell from one organism and insert its nucleus into the egg cell of another organism and then insert it into a third organism b. Therapeutic cloning i. Producing stem cells that can differentiate to give rise to different cell types c. DNA cloning (recombinant DNA technology) i. Primarily used for the pharmaceutical industry and medicine 1. Therapeutic hormones 2. Diagnosis of disease 3. Vaccines 12. Controversy over Cloning a. Eating meat or drinking milk from cloned animal b. Costly c. Potentially using blastocysts from human embryonic tissue d. Use for organ transplants from pigs e. “Restocking” of endangered animals 13. Genetic Engineering a. The direct manipulation of genes for “practical” purposes b. Splicing genes (or a gene) from one organism and inserting them in another 14. Genetically Modified Organism a. An organism that has acquired one or more genes by artificial means i. If the gene is from another species, the organism is also known as a transgenic organism 1. Examples: a. Bt Corn b. Bollgard Cotton c. Roundup Ready Soybeans d. Golden Rice 15. Controversy over GM Plants a. May be hazardous to human health i. Some individuals may be allergic to the bacteria used as a vector b. May be dangerous to the environment 16. Positives a. May reduce the need for pesticides and herbicides b. May be economically positive for farmers if they have a better yielding crop c. May improve nutrition in developing countries 17. Gene Therapy a. A treatment for a genetic disorder in which a patient’s defective gene is replaced with a corrected one 18. Ex Vivo: cells with defective gene removed from the patient and given normal copies of affected DNA and then returned to the body 19. In Situ: carriers with corrective genes introduced into tissue where gene is needed a. Research in some cancers, hemophilia, rheumatoid arthritis, CF, AIDS, SCID 20. Challenges: a. Must reach enough cells to do some good b. Has to get past the human immune system c. Sometimes gene is inserted unpredictably d. Still very expensive 21. Cancer a. Causes: i. Mutations in genes ii. Some mutations may be inherited iii. Others are caused by carcinogens iv. Some occur randomly b. Some progress in reducing death due to cancer i. Early diagnosis ii. Better treatments 1. Hodgkin’s, testicular cancer, childhood leukemia c. What is it? i. Cells dividing without control 1. Often they are abnormal cells ii. Tumor: abnormal growth of cells 1. Benign: growth of cells confined to one area (usually determined not harmful) 2. Malignant: grow uncontrollably and are disruptive to tissues and organs d. Metastasize: ability of cancer cells to travel from original site to other areas of the body and begin growing new tumors i. Two basic ways: 1. Circulatory system 2. Lymphatic system ii. Breast cancer: may spread to lymph nodes, lungs, bones, brain iii. Melanoma: may spread to the lungs iv. Colorectal cancer: may spread to the liver v. Prostate cancer: may spread to bones e. Two genes involved in triggering cancer: i. Protooncogenes: encourage cell growth in normal tissue 1. When protooncogenes mutate into oncogenes, they drive excessive multiplication of cells ii. Tumor suppressor genes: inhibit cell growth 1. When these become inactivated by mutation, there are no “brakes” to stop inappropriate growth f. Internal factors: i. Inherited mutations, hormones, immune conditions and mutations that occur from metabolism g. Discovery of the p53 gene in 1981 located on the short arm of chromosome 17 i. Discovered it was a “tumor killer” in 1989 ii. p53 is a tumor suppressor gene that codes for p53 protein iii. Works in two ways: 1. May turn off cell copying until the cell can repair damage or mistake 2. May activate “cell suicide” (apoptosis) iv. If mutated, can no longer suppress tumor growth h. How to fight cancer: i. Prevention: avoid tobacco, intentional exposure to excessive sunlight, maintain healthy diet and level of exercise ii. Human immune system i. Treatments: i. Conventional: 1. Surgery to remove 2. Radiation: exposure of cancer cells to high energy rays 3. Chemotherapy: treatment with chemicals/drugs 4. Bone marrow transplants ii. New: 1. Angiostatin and endostatin 2. Gene therapy 3. Telomerase 4. Molecularly targeted therapy 5. Immunotherapy j. Cancer is geneticbut not necessarily heritable k. Genetics load the gunenvironment pulls the trigger 1. Homologous Chromosomes: carry genes for the same traits 2. Diploid: cells that have homologous pairs of chromosomes (2n) 3. Haploid: cells that do not have homologous pairs of chromosomes (n) a. Sex cells 4. Karyotype a. First 22 pairs are known as autosomes b. 23rd pair is known as sex chromosomes (determine gender) 5. Cell Cycle a. Interphase: takes up 90% of the cell cycle i. Gap 1: period of cell growth before the DNA is duplicated ii. Synthesis: period when the DNA is duplicated (that is, when chromosomes are duplicated) iii. Gap 2: period after DNA is duplicated; cell prepares for division b. Prophase: first stage of mitosis (usually the longest) i. Chromosomes condense and become visible ii. Microtubules start to assemble iii. Nuclear envelope begins to “break up” c. Metaphase i. Sister chromatids become oriented toward opposite poles ii. Spindle fibers attached at centromeres iii. Chromosomes line up on the “equator” d. Anaphase i. Very rapid ii. Sister chromatids separate and move to opposite poles e. Telophase i. Begins when chromosomes reach poles ii. Chromosomes decondense iii. Nuclear envelope begins to form iv. Overlapping of cytokinesis visible f. Cytokinesis i. Physical division of the cell ii. Usually overlaps with anaphase and/or telophase iii. Different in plants and animals 1. Most animals form cleavage furrow 2. Most plants form a cell plate 6. Meiosis: occurs in germ cells (found within testes/ovaries) a. Only one purposeto form gametes (also called egg/ovum and sperm, sex cells) b. During meiosis, the chromosome number will be reduced by 1/2 each gamete has one pair of homologous chromosomes c. 2 meiotic divisions: Meiosis I and Meiosis II i. Meiosis I 1. DNA is duplicated during interphase prior to meiosis I 2. Duplicated chromosomes line up with partner (homologous chromosomes line up together) 3. Homologous pairs separate 4. Results in 2 daughter cells that have a haploid number of chromosomes (but are still duplicated) 5. Meiosis I/cytokinesis followed by INTERKINESIS a. Interkinesis: a resting phase where no new DNA is made ii. Meiosis II 1. Sister chromatids separate 2. Cytokinesis follows 3. Results in 4 haploid cells iii. Stages of Meiosis I 1. Prophase I a. Homologous chromosomes pair with each other b. Tetrads form synapsis and crossing over occurs (this helps achieve genetic variability) 2. Metaphase I a. Homologous pairs line up on the equator i. Provid es more genetic variability ii. 2^23 possibilities in humans 3. Anaphase I a. Homologous pairs separate and move toward opposite poles 4. Telophase I a. Haploid number of chromosomes at ends of cells 5. Interkinesis a. Resting stage b. No new DNA is made iv. Stages of Meiosis II 1. Prophase II a. Chromosomes condensesister chromatids still attached to centromeres d. Spermatogenesis and Oogenesis i. Spermatogenesis: formation of sperm 1. Diploid spermatogonia grows into spermatocyte which produces 4 equal sized spermatids ii. Oogenesis: formation of an ovum
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'