Donohue dna practice questions

Donohue dna practice questions

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  Biology EOC ExamDNA, RNA, Protein synthesis review questions By: M. Donohue 1. The first step in DNA replication occurs when the DNA molecule separates into two strands. What is the next step of DNA replications? a. DNA polymerase joins the individual nucleotides b. Enzymes produce two new complementary strands c. Enzyme break down the hydrogen bonds between the base pairs d. DNA polymerase proofreads each strand to make sure the sequence is correct 2. Scientists can use evidence to estimate how often a particular segment of DNA in a particular organism will undergo mutation. They can then locate the analogous segment in a related organism, tabulate the differences between segments and then use this “molecular clock” to do which of the following? a. Compare the adaptive fitness of each species in different habitats b. Predict the possible future forms of that the organisms might take as they undergo mutations c. Make an educated guess as to how long ago the two species diverged from a common ancestor d. Evaluate whether the mutations seen in the organisms DNA will remain in the population 3. Hemoglobin is a protein made in red blood cells that carry oxygen. Sickle cell anemia is a disease in which the body produces an abnormal form of hemoglobin with a decreased capacity to carry oxygen. Scientists hope to one day treat sickle-cell anemia with gene therapy: the insertion of strands of DNA into the cells that produce hemoglobin. How might this work? a. The inserted DNA will bind to and fix the abnormal hemoglobin molecules, allowing them to carry more oxygen b. The DNA will provide a blue print for the synthesis of normal hemoglobin, which the cell will then begin to make c. The DNA will shut off cells producing abnormal hemoglobin , allowing other cells to develop d. The DNA will function to take up any extra oxygen the abnormal hemoglobin was unable to carry. 4. Every cell contains DNA. The main purpose of DNA is to store the cell’s genetic information. How does DNA control the cell? a. DNA activates nerve signals b. DNA speeds up chemical reactions c. DNA protects the cells from invaders d. DNA determines what proteins are made 5. The process of transcription is known to have a less effective “proofing” stage to check the sequence of bases than does the process of DNA replication. What effect does this have on the base sequences produced by transcription? a. Errors in the base sequence will result in a damaged strand of DNA b. The base sequences of mRNA can be exactly the same as those on DNA. c. It is more likely that there will be more errors in coding base sequences in mRNA than there will be in DNA. d. It is more likely that there will be fewer errors in coding base sequences ion mRNA than there will be in DNA.
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  6. Our geneticcode is written using the four bases found in DNA. They are arranged in three-letter words called codons. Which statement provides evidence that this code is universal for most living things? a. Some amino acids are coded by more than one codon. b. Each codon codes for the same amino acid in most living things c. Changing the order of these bases changes the amino acid coded for by that codon. d. The codons in the DNA of most living things are mixed with non-coding sequences of bases 7. Look at the figure to the right. What structure does it represent? a. DNA b. RNA c. Protein d. Amino acid 8. The figure to the right shows which of the following? a. Translation b. Replication c. Transcription d. Protein synthesis 9. DNA fingerprinting is used in forensics and other applied fields of science. A fragment if DNA from a piece of hair collected at the crime scene is compared to a fragment of DNA from an individual suspected of being there. What aspect of the cell theory is supported by comparing the fragments shown in the figure? a. Gametes join together to form unique combinations of DNA b. Cells combine to make up larger structures such as hair and tissue c. Cells replicate genetic information before dividing to form new cells d. Cells perform specialized functions according to genetic instructions 10. The diagram below shows part of a DNA molecule. What would happen if two of the base pairs on this strand were switched? a. A different protein would be made b. The strand would not be replicated c. Transcription would stop at that point d. The rest of the DNA strand would detach and unravel
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  11. To demonstrateDNA replication, Doug draws a model on construction paper. See figure. In order to show replication, Dough should carry out which of the following steps first? a. Fold the model in half length wise b. Cut the nitrogenous base pairs where they meet c. Draw a second, identical model of a DNA molecule d. Separate the nitrogenous base pairs from the sugar phosphate backbone 12. Look at the diagrams below. They show the different steps of DNA replication, although not necessarily in order. What are the steps of DNA replication in order? An RNA primer binds to the template to begin synthesis a. 4,1,2,3 b. 4,2,3,1 c. 4,3,2,1 d. 4,1,3,2 mRNA 13. Use the chart and your knowledge of biology to answer the questions below. Codon Which base sequence of a DNA molecule produces a codon on an mRNA molecule that will allow the amino acid valine to be incorporated into a protein? a. T-G-G b. G-A-T c. C-G-A d. C-A-A 14. Genes for medically important proteins can be cloned and inserted into bacteria, as shown in the diagram to the right. Why can bacteria recognize a human gene and then produce a human protein? a. DNA replication in bacteria is the same as in a human b. Bacterial cells contain the same organelles as a human c. The basic components of DNA are the same in humans and bacteria d. Bacterial cells and human cells contain the same kind of chromosomes