Chapter 12 Reading Questions

Transcription

1 Chapter 12 Reading Questions Name Section 11 In Frederick Griffith s experiment, what four substances were given to laboratory mice, and what was the result of each? 4. Which result was surprising, and what was Griffith s conclusion? Oswald Avery helped to identify the transforming factor in Griffith s experiments. What was it, and how did Avery determine this? 4. Alfred Hershey and Martha Chase performed another experiment to verify the transforming factor. This experiment involved bacteria and bacteriophages. a. What are bacteriophages? b. What was done in this experiment, and what was the result?

2 5. When scientists were trying to discover the structure of DNA, they knew it had to perform three significant tasks. What were these tasks? 6. Name the components of a nucleotide and label them on this diagram. 7. Name the four nitrogenous bases found in DNA, identify each as a purine or a pyrimidine, and name the base that each will bond with. Base Type Will bond with What technique was used by Rosalind Franklin to help discover the structure of DNA? 9. What shape, discovered by Watson and Crick, agreed with Franklin s x-ray pattern? 10. The weak hydrogen bonds that form between adenine and thymine, and also between cytosine and guanine, allow for. Section 12 1 Where would you find the DNA of a prokaryote, and what would it look like? 1 If you could stretch out the DNA contained in one human cell, how long would it be? How is it possible for this DNA to fit inside a cell nucleus?

3 1 Describe the process of DNA replication. 14. If one strand of DNA has the base sequence A-T-C-C-G-T-T-G, what will be the sequence of bases on the new strand? 15. What is DNA polymerase, and what is its role in replication? Section What is the purpose of the nucleic acid known as RNA? What are the three types of RNA? 17. How is RNA similar to DNA? 18. What are the three major differences between RNA and DNA? 19. Describe the process known as transcription.

4 20 Define each of the following and give its role in the process of transcription: RNA polymerase Promoter Intron Exon 2 If a strand of DNA has the sequence A-A-C-G-T-T-T-G-G, and if a strand of RNA is produced from this sequence, what will be the sequence of bases on the RNA? 2 What is a codon, and what is its significance? 2 What happens during the process known as translation? 24. Where does an mrna molecule go so that translation can occur? 25. What things are carried by a transfer RNA (trna) molecule? 26. When the trna molecules line up, their amino acids are joined together. What type of bond joins these amino acids? What is the newly formed chain of amino acids called?

5 27. How does the ribosome know when to end the process of translation? Section What are mutations? 29. What is the difference between gene mutations and chromosomal mutations? 30. Mutations involving only a few nucleotides are called. 3 Inserting or deleting a base in a DNA sequence causes a more serious mutation than simply substituting one base for another. Explain why this is true, and give the name for this type of change. 3 Name and describe four types of chromosomal mutations. 3 How do mutations affect the organisms that have them?