Name: Living Environment Date: Period:
Heredity & DNA 1. Arrange the following structures from largest to smallest. a chromosome a nucleus a gene 2. The diagram below represents a portion of a molecule found in cells of the human body. a. What is the name of this molecule? b. What is the function of this molecule? c. What do the different letters represent? d. Why is the sequence of these letters so important? 3. Which nuclear process is represented below?
Protein Synthesis 1. Animal cells utilize many different proteins. Discuss the synthesis of proteins in an animal cell. Your answer must include at least: the identity of the building blocks required to synthesize these proteins the identity of the sites in the cell where the proteins are assembled an explanation of the role of DNA in the process of making proteins in the cell state two differences between DNA and RNA 2. Base your answer to the following question on the diagram below, which represents some biochemical reactions involved in a cellular process. a. What is the name of this process? b. What type of molecule will be produced by this process? c. Which numbered molecule was coded directly from DNA? d. What is the name of the cell organelle labeled 4 in the diagram?
Genetic Changes 1. What is the name given to an alteration of change in DNA? 2. Some organs in the human body are represented in the diagram below. A sudden change in the DNA of cells developing in which organ could be passed to future generations? 3. What is a disadvantage of having a genetic mutation in a human skin cell? 4. People have been warned about the dangers of excessive exposure to radiation during certain medical procedures. What is the most likely reason for this warning? 5. Molecule 1 represents a segment of hereditary information, and molecule 2 represents the portion of a molecule that is determined by information from molecule 1. What will most likely happen if there is a change in the first three subunits on the upper strand of molecule 1? 6. Hemoglobin is a complex protein molecule found in red blood cells. Hemoglobin with the normal sequence of amino acids is able to carry oxygen to body cells effectively. In the disorder known as sickle-cell anemia, one amino acid is substituted for another in the hemoglobin. One characteristic of this disorder is poor distribution of oxygen to the body cells. Explain how the change in amino acid sequence of this protein could cause the results described.
Gene Mutations 1. The diagram below represents a segment of a gene on two chromosomes. The change in the gene sequence is an example of a. 2. Four different segments of a DNA molecule are represented below. In which sequence is there an error in the DNA? 3. An alteration of genetic information is shown below. A-G-T-A-C-C-G-A-T à A-G-T-G-A-T What type of mutation is this an example of? Base your answers to questions 4 through 6 on the information below and on your knowledge of biology. Mutations are often referred to as the "raw materials" of evolution. 4. State one reason that mutations are often referred to as the raw materials of evolution. 5. Use appropriate letters to write a 9-base DNA sequence that could represent a portion of a gene. 6. Show one example of what could happen to the 9-base DNA sequence you wrote in the previous question if a mutation occurred in that gene.
Gene Expression 1. Two different types of cells from an organism are shown below. Explain how these two different types of cells can function differently in the same organism even though they both contain the same genetic instructions. 2. The photograph below was taken of two identical twins. Although identical twins inherit exact copies of the same genes, the twins may look and act differently from each other. Explain how this could occur. 3. When S. marcescens, a bacterium, is grown in a refrigerator, it produces red-colored colonies. However, if the bacterium is grown at room temperature, the colonies are white. Explain why this would occur.
Selective Breeding 1. Modern dogs are direct descendants of the gray wolf. They first appeared about 130,000 years ago. Today, there are about 150 different breeds of domestic dog, a few of which are shown below. Which process brought about by humans created the great variety of modern dogs? 2. Over the past few thousand years, humans have helped to bring about changes in many plant and animal species in order to make them more useful. Examples include strong workhorses, hunting dogs, large-eared corn, and beautiful flower varieties. Which technique was most likely used to develop this new variety of organisms? 3. Selective breeding has been used to improve the racing ability of horses. a. Define selective breeding and state how it would be used to improve the racing ability of horses. b. State one disadvantage of selective breeding.
Genetic Engineering 1. A laboratory technique is represented in the diagram below. Discuss the process used by scientists to insert a gene from one organism into the DNA of another. In your answer, be sure to: Describe the function of a gene Identify the scientific technique used to insert a gene from one organism into another Identify the type of molecule used to cut the gene from the DNA of an organism State one benefit of this technique to humans
Gel Electrophoresis Base your answers to questions 1 through 4 on the information and diagram below and on your knowledge of biology. DNA samples were collected from four children. The diagram below represents the results of a procedure that separated the DNA in each sample. 1. Identify the procedure used to obtain these results. 2. Describe the size of Band X and the speed of movement of Band X through the gel compared to the other bands. 3. The DNA is most similar in which two children? Support your answer. 4. State one way information obtained from this procedure can be used.
Cloning 1. A technique used to alter cells is represented in the diagram below. How does the DNA in the new cells produced by these methods compare to the DNA in the original organism? 2. Scientists have successfully cloned sheep and cattle for several years. A farmer is considering the advantages and disadvantages of having a flock of sheep cloned from a single individual. Discuss the issues the farmer should take into account before making a decision. Your response should include: how a cloned flock would be different from a noncloned flock one advantage of having a cloned flock one disadvantage of having a cloned flock one reason that the farmer could not mate these cloned sheep with each other to increase the size of his flock one reason that the offspring resulting from breeding these sheep with an unrelated sheep would not all be the same