Horizon International School Biology Final Revision Worksheet 2024-2025 PDF

Horizon International School Science Department Academic year 2024-2025 /Term 1 Biology final revision worksheet Name: ……………………………………….……. Grade 10 ( ) Q1. Choose the correct answers....

Horizon International School Science Department Academic year 2024-2025 /Term 1 Biology final revision worksheet Name: ……………………………………….……. Grade 10 ( ) Q1. Choose the correct answers. 1. In prokaryotes, gene expression is regulated by controlling a. transcription. b. replication. c. translation. d. processing. 2. The bacterial lac operon is switched on when a. the operator binds to the promoter. b. lactose binds to the lac operator. c. the operator binds to the lac genes. d. lactose binds to the lac repressor. 3. In a eukaryotic cell, where does mRNA processing take place? a. cytoplasm b. nucleus c. ribosome d. operator 4. What is the term for the nucleotide sequences that are removed during mRNA processing? a. operators b. promoters c. exons d. introns 5. What is the main function of a promoter? a. codes for enzymes that break down sugar b. blocks the action of RNA polymerase c. tells RNA polymerase where to start d. keeps eukaryote genes permanently “off ” 6. Generally, mutations that affect a single gene occur during a. transcription. b. replication. c. translation. d. operation. 7. Cystic fibrosis is an example of a genetic disease caused by the deletion of a nucleotide. What is the term for this type of mutation? a. translocation b. chromosomal c. single-gene d. frameshift 8. Which type of mutation has no effect on phenotype? a. silent b. frameshift c. point d. chromosomal 9. Mutations that can affect the offspring of an organism occur in what cell type? a. body b. germ c. blood d. brain 10. Which of the following is an example of a mutagen? a. repair enzyme b. triglyceride c. UV sunlight d. thymine 11. Bacterial enzymes that cut the DNA of viruses are called a. bacterial helicases. b. restriction enzymes. c. DNA polymerases. d. mapping enzymes. 12. Which technique is used to separate DNA fragments by their size? a. nucleotide sequencing b. genetic engineering c. gel electrophoresis d. gene cloning 13. Suppose a segment of DNA contains five restriction sites for a particular restriction enzyme. How many fragments of DNA will remain after the enzyme is used to cut the DNA? a. 4 b. 5 c. 6 d. 10 14. Some restriction enzymes leave behind "sticky ends," or tails of a. repeating bases. b. exposed bases. c. paired bases. d. restricted bases. 15. What do the bands on a restriction map show? a. the genes being expressed b. DNA sequences c. locations of damaged genes d. sizes of DNA fragments 16. Which of the following statements about polymerase chain reaction (PCR) is true? a. produces RNA segments b. requires primers and nucleotides c. builds new polymerases d. occurs inside bacteria 17. The first step of PCR is to heat a DNA molecule to more than 90°C. What is the function of this step? a. to force DNA ligation to occur b. to mutate the DNA sequence c. to allow polymerases copy DNA d. to separate the DNA strands 18. The main role of primers during the PCR process is to a. free bound nucleotides from the template strand. b. form hydrogen bonds between nucleotides. c. provide a starting point for DNA synthesis. d. separate polymerases from DNA. 19. During each PCR cycle, what happens to the number of copies of a DNA segment? a. It stays the same. b. It doubles. c. It quadruples. d. It increases to 1 billion. 20. Scientists use PCR primarily to a. amplify DNA. b. isolate DNA. c. collect DNA. d. preserve DNA. 21. Which phrase is true for a DNA fingerprint? a. It cannot distinguish among siblings. b. It is a type of restriction map. c. It shows a person’s phenotype. d. It focuses on coding regions of DNA. 22. Which of the following is the basis for the molecular differences identified by DNA fingerprinting? a. each person’s entire genome b. regions of noncoding DNA c. DNA fragments with genes d. the X and Y chromosomes 23. The pattern of bands on a DNA fingerprint shows the sizes of DNA fragments related to the a. number of repeat sequences. b. order of genes on a segment of DNA. c. sequence of nucleotides in a gene. d. number of restriction sites. 24. The chance that two people both have three repeat sequences at location A is 1 in 500. The chance that two people have four repeat sequences at location B is 1 in 800. What is the probability that two people have the same number of repeats in both location A and location B? a. 1 in 5,000 b. 1 in 13,000 c. 1 in 40,000 d. 1 in 5,000,000 25. DNA fingerprinting can be used to a. assess actual disease risk. b. prove a family relationship. c. find all recessive alleles. d. measure gene expression. 26. Which of the following are examples of clones? a. flowers from one plant b. kittens from the same litter c. identical twin sisters d. offspring of glowing mice 27. DNA that contains genes from more than one organism is called a. restricted DNA. b. cloned DNA. c. recombinant DNA. d. plasmid DNA. 28. Scientists commonly use bacteria in genetic engineering because bacteria a. naturally make insulin. b. infect viruses. c. mutate quickly. d. can contain plasmids. 29. Which statement is true of all genetically engineered organisms? a. They have altered genomes. b. They are implanted with the Bt gene. c. They age more quickly than normal. d. They contain bacterial genes. 30. Plants that contain recombinant DNA are called a. clones. b. knockouts. c. transgenic. d. plasmids. 31. The two main goals of the Human Genome Project are to sequence all of the DNA base pairs of the human chromosomes and to a. compare the human genome with those of other species. b. identify all of the genes within the genome. c. classify all of the alleles that cause genetic disorders. d. find the closest living relative to humans. 32. Gene sequencing defines the order of a. DNA nucleotides in genes or genomes. b. genes on chromosomes. c. chromosomes in an organism’s genome. d. amino acids in proteins. 33. The study of the proteins that result from an organism’s genome is called a. genomics. b. bioinformatics. c. proteomics. d. gene sequencing. 34. Which of the following terms is used to describe the use of computer databases to analyze and organize biological data? a. gene sequencing b. DNA microarrays c. proteomic studies d. bioinformatics 35. DNA microarrays can be used to compare different cell types by showing a. recombinant DNA sequences. b. patterns of gene expression. c. very small DNA fragments. d. functions of proteins. 36. What type of mutation has occurred here? T-G-A-C-C-A T-G-A-G-C-A a. Substitution b. Deletion c. Insertion d. Frameshift 37. DNA molecule segment is : TTACGCAAG The mutated DNA segment is TTCGCAAG. This is an example of ___ mutation. a. Substitution b. Deletion c. Insertion d. Inversion 38. DNA molecule segment is: TTACGCAAG The mutated DNA segment is TTACGCAAC. This is an example of ______ mutation. a. Substitution b. Insertion c. Inversion d. Translocation 39. DNA molecule segment is : TTACGCAAG The mutated DNA segment is TTCGCAAG. This is an example of ______ mutation. a. Substitution b. Deletion c. Insertion d. Inversion 40. In eukaryotes, proteins that help the RNA polymerase bind to the regulatory region for transcription are called ____________. a. transcription factors b. topoisomerase c. regulatory genes d. activators 41. Most gene regulation happens at which step along the way? a. translation b. transcription c. signal transduction d. DNA replication 42. what does a promoter do? a. it allows a gene to be transcribed b. it creates a DNA segment c. it is another word for ribosomes d. it is another word for RNA 43. A protein that binds to the operator and blocks the RNA polymerase a. regulator b. repressor c. activator d. corepressor 44. In the lac operon model the genes within the operon will be expressed if: a. lactose is absent in the cell b. glucose is present in the cell c. lactose is present in the cell d. glucose is absent in the cell 45. What does the lactose do to the Operon? a. Blocks transcription because of the energy it provides b. Allows the repressor to be unbind from the Operator. c. The lactose binds the lactose and stops transcription d. Allows for the transcription to speed 46. How can a person's muscle cells have the same exact DNA sequences as their nerve cells even though the look and perform completely different? a. The two different cells become mutated b. The proteins expressed in each cell are different c. They actually have different DNA in the two types of cells. d. The genome of the different cells changes 47. What is the role of operons in prokaryote gene expression? a. It makes the genes prokaryotes be turned on b. It accounts for the regulation of gene activity in response to the needs of the cells c. To make DNA for the gene d. To make the gene turn of and off 48. The "on/off" switch for an operon is called the a. promoter b. enhancer c. operator d. gene 49. An operon consists of all the the following EXCEPT a. operator b. promoter c. regulatory gene d. genes of the operon 50. The repressor is the protein product of a(n) a. operator b. regulatory gene c. lac gene d. corepressor 51. The complete set of genetic material is called: a. Genetics b. Genome c. Karyotype d. Gene 52. In order to cut DNA into smaller pieces we must use: a. Lipase enzyme b. Lactase enzyme c. Restriction enzyme d. Pepsin enzyme 53. A type of cell that can differentiate and become any type of cell that is needed in the body? a. Blood cells b. Muscle Cells c. Skin Cells d. Stem Cells 54. What is gel electrophoresis? a. Is used to separate and analyze the differently sized fragments b. Is used to break larger molecules into smaller c. Is used to assemble the base pairs by adding a chemical dye d. Is used to read the base sequences 55. The process when an electrical current is used to separate a mixture of DNA is called a. Recombinant DNA b. Plasmid c. Gel electrophoresis d. Restriction enzyme 56. How do restriction enzymes "know" where to cut DNA a. A specific sequence of nucleotides b. They cut randomly c. Distance from the centromere d. No answer. 57. "Sticky-ends" are DNA strands with: a. single-stranded ends b. ends cut flat by an enzyme c. no way to be recombined d. no answer 58. GMO stands for a. Genetically Made Organism b. Growing More Organisms c. Genetically Modified Organism d. Growing Many Organisms 59. Why do the fragments of DNA in gel electrophoresis travel away from the negative electrode? a. DNA is negatively charged so attracted to the positive end of the unit b. DNA is positively charged to attracted to the negative end of the unit c. the agarose gel in negatively charged d. the agarose gel is positively charged 60. The PCR technique was developed by_________. a. Kohler b. Altman c. Milstein d. Kary Mullis Q.2 Answer the following questions. 1. Why do the cells in your body differ from each other? because they express different sets of genes 2. What role do transcription factors play in a cell? Transcription factors bind to the DNA and help RNA polymerase know where a gene starts. 3. What is a TATA box? A TATA box is a promoter that is found in almost all eukaryotic cells. 4. What is “sonic hedgehog” an example of? a protein that helps control the expression of many other genes and plays an important role in establishing body pattern 5. What is the difference between an exon and an intron? An exon is a sequence of nucleotides that is expressed in a protein, whereas an intron is an intervening sequence of nucleotides that will be removed during processing 6. Make an analogy to help you remember what a promoter is. A promoter is like a choir director who shows you when to start singing. 7. List two types of gene mutations. point mutation/substitution; frameshift mutation 8. List two types of chromosomal mutations. gene duplication; translocation 9. Which type of mutation affects more genes, a gene mutation or a chromosomal mutation? chromosomal mutation 9. What leads to gene duplication? unequal crossing over 10.What is a translocation? the attachment of a piece of one chromosome to a nonhomologous chromosome 11.For a mutation to be passed to offspring, in what type of cell must it occur? germ cells/gametes 13. Can DNA polymerase catch and correct every replication error? No 14. What is a mutagen? an agent in the environment that can change DNA 15. How does UV light damage the DNA strand? UV light can cause neighboring thymine nucleotides to break their hydrogen bonds to adenine and bond with each other instead 16. What is a mutation? a change in an organism’s DNA 17. If a nucleotide is deleted from a strand of DNA, what type of mutation has occurred? a frameshift mutation 18. List five ways in which scientists study and manipulate DNA. artificial nucleotides to sequence genes, copying genes, chemical mutagens, computers, enzymes, bacteria 19. What is a restriction enzyme? enzymes (from bacteria) that cut DNA at specific nucleotide sequences 20. What is the nucleotide sequence at which a restriction enzyme cuts DNA called? a restriction site 21. Why would different restriction enzymes cut the same DNA molecule into different numbers of fragments? different restriction enzymes have different restriction sites 22. After DNA is cut with a restriction enzyme, how is the mixture of DNA fragments sorted? by gel electrophoresis, on the basis of the size of the fragments 23. How does gel electrophoresis work? DNA is loaded into a gel that has a positive electrode at one end and a negative electrode at the other end. The DNA fragments (negatively charged) are pulled through the gel toward the positive electrode. The pores in the gel slow down larger fragments, and smaller fragments will travel a greater distance in a certain length of time. 24. How do different fragments of DNA show up on a gel? Different sizes of fragments show up as different lines, or bands, on the gel. 25. What information does a restriction map give about DNA? What information is not given by a restriction map? the lengths of DNA fragments between restriction sites, but nothing about the DNA sequence 26. How are restriction maps used? genetic engineering, studying gene mutations and diagnosing genetic disorders 27. How does a restriction enzyme limit, or restrict, the effect of a virus on a bacterial cell? by cutting the viral DNA 28. The prefix electro- means “electricity.” The suffix -phoresis comes from a Greek word that means “carrying.” How do these two meanings relate to what happens in gel electrophoresis? DNA is carried by electricity. 29. What is PCR? a technique that makes many copies of a particular segment of DNA 30. Why is PCR useful? without many copies of DNA there is too little to study 31. What four materials are needed for PCR? DNA to be copied, polymerases, nucleotides, primers 32. Why are primers needed in the PCR process? to start the new strands of DNA 33. DNA polymerase is an enzyme that helps put DNA molecules together. A chain reaction is a process in which one event leads to the next event and the effect is stronger over time. How does the combination of these two terms describe what happens during PCR? In PCR, polymerase makes more and more copies of DNA as the cycles continue 34. The verb to prime means “to prepare.” How does this meaning tell you what a primer does in PCR? The primer prepares a DNA strand to be copied. 35. How does identification through DNA fingerprinting depend on probability? in order to identify a particular person with a great degree of certainty there must be a low probability that the DNA fingerprints from two different people randomly match. 36. The chance that two people have four repeats in location A is 1 in 100. The chance that two people have eight repeats in location B is 1 in 50. The probability that two people have three repeats in location C is 1 in 200. What is the probability that two people would have matching DNA fingerprints for these three locations by chance? 1 in 1 million (1/100 x 1/200 x 1/50) 37. Why does using more regions of the genome decrease the probability that two people would have the same DNA fingerprint? the more regions used, the lower the probability that two people would randomly match 38. List two ways in which DNA fingerprinting is used for identification. criminal cases, immigration, species identification, biodiversity studies, tracking genetically modified crops 39. One definition of the term fingerprint is “a distinctive mark or characteristic.” How does this meaning relate to a DNA fingerprint? A DNA fingerprint is a distinctive pattern of bands on a gel 40. What is genetic engineering? changing an organism’s DNA to give the organism new traits 41. What is recombinant DNA? DNA that contains genes from more than one organism 42. Why are plasmids used to produce bacteria with recombinant DNA? Plasmids are loops of DNA that replicate separately from bacterial DNA. 43. What is a transgenic organism? an organism that has one or more genes from a different organism inserted into its genome 44. The term recombine means “to combine, or join, again.” How is the meaning of recombine related to the production of recombinant DNA? an organism’s DNA is put back together with a new gene from a different organism 45. The prefix trans- means “across,” and genic means “relating to genes.” How do these two meanings help to explain the meaning of transgenic? genes across organisms 46. What is bioinformatics? the use of computer databases to organize and analyze biological data 47. Why is bioinformatics important for genomics research? The databases are needed to store and compare the huge amount of information about genomes, as well as provide a way in which to model gene functions and identify genes. 48. What are DNA microarrays? small chips that allow the study of many genes and their expression at one time 49. How can DNA microarrays compare gene expression in different cells? Genes that are being expressed show up as glowing dots on a microarray; the pattern of dots can be compared across different types of cells to compare gene expression 50. What is proteomics? the study and comparison of all proteins in an organism; can include studies of functions and interactions of proteins 51. What are some potential benefits and uses of proteomics? studies of evolutionary relationships, proteins in human diseases, personalized medical treatments 52. The suffix -ic means “related to.” A genome is all of an organism’s DNA. A proteome is all of an organism’s proteins. What does this information tell you about genomics, proteomics, and bioinformatics? Genomics is related to all of an organism’s DNA, proteomics is related to all of an organism’s proteins, and bioinformatics is related to biological information 53. An array is an organized arrangement or a large number of objects. The prefix micro- means “small.” How are these meanings related to the definition of a DNA microarray. A DNA microarray is a small chip that contains a large number of genes in an organized pattern. With My Best Wishes