DNA, RNA, Protein Synthesis Keystone 1. During the process shown above, the two strands of one DNA molecule are unwound. Then, DNA polymerases add complementary nucleotides to each strand which results in the formation of two identical DNA molecules. This process is known as DNA. A. translation B. replication C. cloning D. transcription 2. When a molecule of double-stranded DNA undergoes replication, it results in A. two double-stranded DNA molecules, each composed of one new and one old strand. B. one double-stranded DNA molecule composed only of entirely new strands. C. three double-stranded DNA molecules, each composed of sections of old and new strands. D. four double-stranded DNA molecules, each composed only of old strands of DNA. 3. Which of the following correctly organizes genetic material from the broadest category to the most specific category? A. genome chromosome gene DNA molecule B. genome DNA molecule chromosome gene C. genome chromosome DNA molecule gene D. gene chromosome DNA molecule genome
4. How is the nucleus involved in the production of enzymes? The nucleus translates the ribosomal RNA for the enzymes to be synthesized in mitochondria. A. The nucleus is involved in the packaging and transportation of enzymes outside of the cell. B. The nucleus receives the messenger RNA and is the site where enzymes are synthesized. C. The nucleus transcribes and releases messenger RNA signaling for the enzymes to be synthesized. D. 5. A diagram demonstrating the process of protein translation is shown below. The structure labeled with a question mark in the diagram represents A. a chloroplast. B. a ribosome. C. a mitochondrion. D. a vacuole. 6. The sequence of bases on one strand of a DNA molecule is ATTGCCCATG. What will be the sequence on the complementary strand? A. ATTGCCCATG B. GCCATTTGCA C. TAACGGGTAC D. CGGTAAACGT
7. The nucleotide of DNA is one large molecule composed of three smaller molecules. Which of the following sets of molecules bond together to form a nucleotide? A. deoxyribose, a nitrogen base, a phosphate group B. a purine, a pyrimidine, and a five-carbon sugar C. adenine, thymine, and cytosine D. a nitrogen atom, a phosphate atom, and a five-carbon sugar 8. From the list below, select the items that are used during RNA translation. A. I, III, and IV only B. III and IV only C. II, III, and IV only D. I, II, III, and IV I. mrna II. trna III. ribosome IV. amino acid 9. After the process of occurs, each daughter cell receives an exact copy of the parent cell's DNA. A. DNA transcription B. DNA elongation C. DNA translation D. DNA replication 10. Which choice below correctly summarizes the base-pairing rules in DNA? A. B. C. D. A-G C-T A-U C-G A-T C-G A-C T-G
11. Which of the following cellular materials is solely composed of DNA and proteins? A. chromosomes B. Golgi complex C. mitochondria D. ribosomes 12. Which of the following is a true statement about codons? A. A codon is a sequence of four nitrogenous bases. B. In translation, an mrna codon is recognized by its complementary amino acid. C. A codon is a sequence of three amino acids. D. In translation, an mrna codon is recognized by its complementary trna. 13. Which of the following is the term for one possible form of the gene for a particular trait? A. sex-linked trait B. autosomal trait C. codon D. allele 14. Cells store genetic information in DNA. That genetic information is used to synthesize. A. genes B. polysaccharides C. carbohydrates D. proteins 15. Which of the following correctly describes the components of DNA? A. B. DNA is made up of nucleotides consisting of the sugar deoxyribose, a phosphate, and one of four nitrogenous bases. DNA is made up of proteins consisting of the sugar deoxyribose, a phosphate, and one of four nitrogenous bases. C. DNA is made up of proteins consisting of the sugar ribose, a carbon ring, and one of four
D. phosphorus bases. DNA is made up of nucleotides consisting of the sugar ribose, a carbon ring, and one of four phosphorus bases. 16. Integral membrane proteins, such as transport proteins, are permanently attached to cellular membranes. After integral membrane proteins are synthesized, which organelle would aid in transporting them to their final destination? A. mitochondrion B. endoplasmic reticulum C. plasma membrane D. chloroplast 17. DNA contains instructions for making the different molecules, such as proteins, that the cell needs for growth and function. To use these instructions, the DNA must first be into. A. transcribed; amino acids B. translated; amino acids C. translated; mrna D. transcribed, mrna 18. The DNA of a cell is organized into structures. What are these structures called? A. nuclei B. mitochondria C. vacuoles D. chromosomes 19. The picture below shows the process of transcription.
During transcription, enzymes bind to a molecule of DNA. Then, the enzymes unwind and separate the DNA's double helical strands. As the molecule unwinds, complementary nucleotides pair with one of the DNA strands to form A. a DNA polymerase. B. an RNA molecule. C. an identical strand of DNA. D. a protein molecule. 20. Which of the following best describes the product of DNA transcription? A. a DNA molecule B. a chromosome C. an RNA molecule D. a protein 21. What is a gene? A. a set of instructions in the DNA sequence of an organism B. a characteristic of any organism C. a sex cell that aids in organism reproduction D. any single amino acid in a multicellular organism 22. In eukaryotic organisms, DNA transcription occurs in the of a cell. A. mitochondria B. cytoplasm C. nucleus D. ribosome
23. The genetic information that is passed from a parent to its offspring is found in. A. hydrogen bonds B. amino acids C. DNA molecules D. carbon atoms 24. Which of the following best describes the product of RNA translation? A. a DNA molecule B. a chromosome C. a protein D. an RNA molecule 25. Which of the following is true regarding the process shown above? The process shown above is known as replication and involves the production of DNA from RNA. A. B. C. D. The process shown above is known as transcription and involves the production of proteins from DNA. The process shown above is known as cloning and involves the production of RNA from protein molecules. The process shown above is known as translation and involves the production of proteins from RNA.
26. Proteins play a variety of roles within cells, but there are many steps that must be undertaken to make these proteins and deliver them to where they need to go. The above picture implies that no organelles are necessary for the synthesis and transportation of proteins. A. organelles must interact with each other to synthesize and transport proteins. B. only the organelles shown in the picture are important to cells. C. organelles act independently when synthesizing and transporting proteins. D. 27. Hemoglobin is a protein containing iron, which is involved with oxygen transport in the blood. In which organelle would this protein be sorted? A. mitochondrion B. lysosome C. nucleus D. Golgi apparatus 28. A nucleotide is about to be added to a growing strand of DNA. What factor determines which type of nucleotide will be added? A. base-pairing rules B. the length of the DNA strand C. random chance D. the type of cell in which replication is taking place
29. All cells contain DNA, which provides information for the cells to make A. different kinds of proteins. B. new types of organisms. C. different kinds of DNA. D. new types of genes. 30. How are complementary strands of DNA held together? A. with hydrogen bonds connecting complementary sugars B. with phosphodiester bonds connecting sugars and phosphate groups C. with ionic bonds between sugars and phosphate groups D. with hydrogen bonds connecting complementary bases
Answers 1. B 2. A 3. C 4. D 5. B 6. C 7. A 8. D 9. D 10. C 11. A 12. D 13. D 14. D 15. A 16. B 17. D 18. D 19. B 20. C 21. A 22. C 23. C 24. C 25. D 26. B 27. D 28. A 29. A 30. D Explanations 1. The process of DNA replication begins with one double-stranded molecule of DNA. The two strands of this molecule separate during replication, and DNA polymerases add complementary nucleotides to each strand. The end results of DNA replication are two identical DNA molecules. 2. When a molecule of double-stranded DNA undergoes replication, it results in two double-stranded DNA molecules, each composed of one new and one old strand. This is known as semi-conservative replication, and the process is shown below.
3. From the broadest category to the most specific category, genetic information is organized as follows: genome chromosome DNA molecule gene The genome of an organism refers to its complete genetic makeup and includes the organism's entire set of chromosomes. Chromosomes are single pieces of DNA, along with the proteins that package and control their functions. DNA (deoxyribonucleic acid) is a type of nucleic acid that carries all the instructions for the characteristics of an organism. Genes are specific segments of DNA that influence a particular trait or group of traits. 4. The nucleus serves as the control center for the cell. It houses the DNA, which contains the directions for making all of the proteins needed for life functions. The nucleus transcribes messenger RNA from DNA and releases it, signaling for the enzymes to be synthesized. 5. Ribosomes are RNA and protein complexes that are found in all cells. These complexes help cells during protein translation by joining amino acids together to form polypeptides. 6. According to the base-pairings rules, adenine (A) always forms bonds with thymine (T), and cytosine (C) always forms bonds with guanine (G). 7. Each nucleotide is made of a phosphate group, deoxyribose, and a nitrogen base. Deoxyribose is a fivecarbon sugar. The only portion of the nucleotide that can vary is the nitrogen base. DNA has four types of nitrogen bases: adenine, thymine, cytosine, and guanine. Adenine and Guanine are purines, or nitrogen bases made of two rings of carbon and nitrogen atoms. Thymine and cytosine are pyrimidines, or nitrogen bases made of a single ring of carbon and nitrogen atoms. 8. The key items involved in RNA translation are: mrna - a transcript of DNA which serves as instructions for polypeptide formation. amino acid - a single building block of a protein.
trna - a molecule that carries a specific amino acid and recognizes its complementary base sequence on an mrna strand. ribosome - an organelle which serves as the "factory" where amino acids are added to a growing polypeptide chain. 9. After the process of DNA replication occurs, each daughter cell receives an exact copy of the parent cell's DNA. During DNA replication, the parent cell's double-stranded DNA molecule separates into two single strands. Then, a new strand of DNA is made that corresponds to each old strand. This leaves two doublestranded DNA molecules, each with half of the original molecule. 10. The base-pairing rules that govern the binding of complementary DNA strands are shown below. Adenine (A) pairs with thymine (T). Cytosine (C) pairs with guanine (G). 11. While mitochondria contain genetic material, chromosomes are the only objects in a cell that are composed solely of DNA and proteins. Genetic information is stored in genes on the chromosomes, which, in turn, are located in a cell's nucleus. 12. Transfer RNA (trna) is a molecule that carries a specific amino acid and recognizes its complementary base sequence on an mrna strand. 13. An allele is one possible form of the gene for a particular trait in a given population. Humans have two alleles for each trait. These alleles can be dominant or recessive. Dominant alleles are always expressed in the phenotype (traits) of organisms that have either one or two copies of the allele. Recessive alleles are expressed only in organisms that have two copies of the recessive allele. 14. The genetic information stored in cells is used to synthesize proteins. During protein synthesis, DNA is first replicated to form other copies of DNA. Then, it is transcribed to form strands of RNA. Finally, the RNA is translated into proteins which help the body to perform numerous functions. 15. DNA is made up of nucleotides consisting of the sugar deoxyribose, a phosphate, and one of four nitrogenous bases. The four nitrogenous bases include adenine, cytosine, guanine, and thymine. The sequence of the nucleotides within DNA provides the instructions needed to construct proteins. 16. The endoplasmic reticulum aids in the transportation of proteins, including integral membrane proteins. The Golgi apparatus and endoplasmic reticulum work closely together in the total process of modifying, packaging, and transporting proteins.
17. DNA contains instructions for making the different molecules, such as proteins, that the cell needs for growth and function. To use these instructions, the DNA must first be transcribed into mrna. Then the mrna is translated into proteins. 18. In simple cells like bacteria, DNA exists as a long molecule. But in more complex cells, the DNA exists in numerous different segments. These segments of DNA, along with their associated proteins, form compact structures called chromosomes. Genetic information is stored in genes on the chromosomes, which, in turn, are located in a cell's nucleus. 19. During transcription, enzymes bind to a molecule of DNA. Then, the enzymes unwind and separate the DNA's double helical strands. As the molecule unwinds, complementary RNA nucleotides temporarily pair with the nucleotides on one of the DNA strands to form an RNA molecule. Once base pairing is complete, the new RNA molecule (mrna) breaks away from the DNA strands, and the DNA strands reattach to each other. RNA is very similar to DNA, except RNA contains the nitrogenous base uracil (U) rather than thymine (T), which is present in DNA. 20. In DNA transcription, a segment of DNA is copied, or "transcribed," to a complementary strand of messenger RNA. This mrna strand contains a copy of the information in its specified DNA segment. It then moves from the nucleus to the cytosol where translation takes place. 21. A gene is a set of instructions in the DNA sequence of an organism. Genes are located in the chromosomes of each cell and specify the sequence of amino acids in an organism's polypeptides. Most organisms have two genes for each trait, one on each of the homologous chromosomes in a cell's nucleus. 22. In eukaryotic organisms, each cell's DNA is held in the nucleus. Since transcription involves the copying of DNA, it takes place in the nucleus. The resulting mrna strand then moves from the nucleus to the cytosol where translation takes place. 23. The genetic information that is passed from a parent to its offspring is found in DNA molecules. DNA contains genes, which, in turn, contain information such as hair color, eye color, and health factors. Genes code for the production of proteins that allow different traits to be expressed. 24. In translation, an mrna transcript is used as the instructions to link amino acids together in a specific sequence. The amino acid sequence is called a polypeptide chain, which eventually builds into a protein. 25. The process shown in the diagram is known as translation, and it involves the production of proteins from RNA. A codon is a series of three nucleotides that correspond to a specific amino acid. During the process of translation, a codon on an mrna molecule attaches to a ribosome. Then, the matching trna molecule (anticodon) carries the appropriate amino acid to the ribosome where it is linked to other amino acids via peptide bonds. Once an amino acid is attached, the ribosome slides to the next codon on the mrna molecule and repeats the process.
The chain of amino acids continues to grow until the ribosome reaches a stop codon on the mrna strand. The stop codon signals that no more amino acids should be added, and the protein is complete. 26. Organelles must interact with each other chemically and physically when carrying out an organism's life processes. For example, during protein synthesis: DNA is transcribed in the nucleus into mrna. The mrna travels into the cytoplasm, attaches to ribosomes, and is translated into a protein. The protein is pushed into the ER (endoplasmic reticulum) where it is stored for later use or packaged into vesicles. These vesicles can then be transported to the cell membrane and exported or to the Golgi apparatus where a more complex molecule may be formed. These complex molecules can then be repackaged into vesicles and transported to the cell membrane for export. 27. The Golgi apparatus is involved in the sorting of proteins. The Golgi apparatus also plays a significant role in modifying and packaging other macromolecules in the cell. 28. The type of nucleotide that is added to a growing strand of DNA is determined by base-pairing rules. These base-pairing rules are listed below. Adenine (A) pairs with thymine (T). Cytosine (C) pairs with guanine (G). 29. All cells contain DNA, which provides information for the cells to make different kinds of proteins. The proteins made by DNA have many jobs, such as acting as enzymes, storage, transport, and defense against diseases. 30. Complementary DNA strands are held together with hydrogen bonds connecting complementary nitrogenous bases. Adenine binds with thymine, and cytosine binds with guanine.