Name: Key Block: Define the following terms: 1. Chromosome-organized structures of DNA that stay inside the nucleus 2. DNA-Deoxyribonucleic Acid-the molecule that contains the code for traits 3. Gene-sections of chromosomes that code for specific traits 4. Environmental Trait-characteristics influenced by where and how an organism lives 5. Inherited Trait-characteristics that are genetically passed from parent to offspring 6. Alleles-options or choices for specific genes 7. Probability-the likelihood, or chance, of an event happening Answer the following questions: 8. What important contribution did Gregor Mendel make to our body of knowledge about genetics? Studied pea plants and discovered dominant and recessive traits 9. What important contribution did Rosalind Franklin make to our body of knowledge about genetics? Took a famous photo (Photo 51) of DNA and discovered that DNA has a spiral shape 10. What important contribution did James Watson and Francis Crick make to our body of knowledge about genetics? Discovered that DNA is a double helix 11. What is the shape of DNA? Spiral, twisted ladder 12. What is the structure of DNA? Draw and describe. Double helix The structure of DNA is two phosphate sugar chains held together by nitrogen bases 13. What makes up the backbone of DNA? (known as the side poles of the ladder) Sugar and phosphates 14. What makes up the inside of the DNA molecule? (steps or rungs of the ladder) Nitrogen bases 15. How do the bases pair together? A T, and C G
16. Complete the complementary strand for the strand of DNA given. A T C A G C C T T A G T A G T C G G A A T C 17. Explain the difference between inherited and environmental traits. Inherited traits are passed from parent to offspring and are a part of an organism s genetic makeup. Environmental traits are a result of an organism s environment. 18. Give two examples of inherited traits. Skin color, height, tongue rolling, and long second toe 19. Give two examples of environmental traits. Favorite music, dyeing hair, choice of clothing style, language spoken 20. Why do identical twins have the same DNA and not the same personality? Personality is not a result of DNA (inherited traits), but environmental ones instead.
Short answer Questions you may continue your answer on a separate sheet of paper. 1. Use a DNA strand to DRAW and EXPLAIN how a strand of DNA would replicate. Why is it important for DNA to be able to make an exact copy (how does that ability help an organism live?)? DNA must be able to make an exact copy of itself to pass on the stored/coded information to the next generation. For the process of how it happens, remember: A. Untwist, B. Unzip, C. New Nucleotides come in and use the pattern as a template to make an exact copy with: D. one old strand and one new strand. Full answer: 2. Give 2 examples of environmental traits. Explain why they are considered to be environmental traits. Give 2 examples of inherited traits. Explain why they are considered to be inherited traits.
Answers will vary, but should include that inherited traits are passed down IN THE DNA, and environmental/acquired traits may be learned, and/or will be influenced by surroundings. 3. Scientific history is full of DRAMA. Pick one of our four scientists from this unit and share their dramatic story. Answers will vary, but a discussion of Mendel should include Fisher s analysis of Mendel s work and how his data was too perfect. Why is that ok and why is that not ok? What would a trained scientist do if he/she had issues with his/her experimental data? A discussion of Franklin/Watson and Crick should include how they looked at her data without explicit permission and how they received credit and she did not and passed away due to cancer she probably got from her research with X-rays.
4. Draw and label a DNA strand. Be detailed and include ALL parts in the proper places and include at least 8 bases per strand. P = phosphates, S = sugar (deoxyribose), A = adenine, T = thymine, G = guanine, and C = cytosine. Your strand should have 8 bases.