Student Exploration: Mouse Genetics (One Trait AND Two Traits)

Vocabulary: allele, DNA, dominant allele, gene, genotype, heredity, heterozygous, homozygous, hybrid, inheritance, phenotype, Punnett square, recessive allele, trait Gizmo Warm-up Heredity is the passage of genetic information from parents to offspring. The rules of inheritance were discovered in the 19th century by Gregor Mendel. With the Mouse Genetics (One Trait) Gizmo™, you will study how one trait, or feature, is inherited. 1. Drag two black mice into the Parent 1 and Parent 2 boxes. Click Breed several times. What do the offspring look like? [All of the offspring will have black fur ] The appearance of each mouse is also called its phenotype. 2. Click Clear, and drag two white mice into the parent boxes. Click Breed several times. What is the phenotype of the offspring now? [ All offspring are white fured. ] 3. Do you think mouse offspring will always look like their parents? [Yes. But it will different ways the offspring will very from the parent. ] Explain: [ For example if your mom has sharp ears and your dad has flat ears, you could get a mixture of both types of ears. ]_ Activity A: Patterns of inheritance Get the Gizmo ready: ● Click Clear. ● Drag a black mouse and a white mouse into the parent boxes, but don’t click Breed yet. Question: What patterns are shown by offspring traits? Downloaded by james mwangi () lOMoARcPSD| 1. Predict: What do you think the offspring of a black mouse and a white mouse will look like? [ I think most of them will be black and some will be white ] 2. Observe: Click Breed several times. What do you see? [ they are all black ] 3. Observe: Drag two offspring into the Holding Cages. These mice are called hybrids because their parents had different traits. Click Clear, and then breed the two hybrids. What do you see now? [4 black mice and 1 white mice. ] 4. Experiment: Turn on Show statistics. Click Breed until there are 100 offspring. How many offspring were black? [ 76 ] How many were white? [ 24 ] 5. Explore: Try other combinations of mouse parents. Write the results of each experiment in your notes. When you have finished, answer the following questions. (Note: You can refer to the parents as “pure black,” “pure white,” or “hybrid.”) A. Which parent combination(s) yield only white offspring? [Both parents are white mice ] B. Which parent combination(s) yield only black offspring? [ Both parents are black mice ] C. Which parent combination(s) yield a mixture of black and white offspring? [ A parent being, for example Ff and the second parent will be ff. ] Activity B: Genetics basics Get the Gizmo ready: ● Click Clear. ● Drag a black mouse and a white mouse into the parent boxes. Introduction: Inherited traits are encoded on a molecule called DNA (deoxyribonucleic acid). Genes are segments of DNA that control a particular trait. Most genes have several different versions, or alleles. The genotype is the allele combination an organism has. Question: How do alleles determine fur color? 1. Observe: Turn on Show genotype. Move your cursor over a mouse to see its genotype. A. What is the genotype of the black parent? [FF ] White parent? [ ff ] Downloaded by james mwangi () lOMoARcPSD| These mice are homozygous for fur color, meaning both alleles are the same. B. Click Breed. What is the genotype of the offs