Mutations and Disorders TAKE HOME TEST HBIO COLOSI 1. The diagram below shows a process that can result in the alteration of the composition of chromosomes. A piece of each chromosome in the diagram has broken off and been reattached to the other chromosome, resulting in an exchange. The process that occurs when a section of a chromosome breaks off and reattaches to another chromosome is known as _______. A. chromosome deletion B. chromosome translocation C. chromosome nondisjunction D. chromosome inversion 2. Sometimes, during the process of replication, the DNA code is copied incorrectly, and an incorrect nucleotide is attached to the new strand of DNA. This incorrect copy is known as a A. codon. B. mutation. C. duplicate. D. protein. 3. When environmental conditions change, it is more likely that at least some members of a species will survive if A. there is variation among the members. B. the members are genetically identical. C. the species reproduces asexually. D. the species requires very specific environmental conditions. 4. Triple X syndrome, or trisomy X, occurs when a female has an extra X chromosome in each of her cells. This results when the mother's reproductive cells divide improperly, and two X chromosome are moved into one gamete. When that gamete is fertilized and the father's DNA and X chromosome are combined with the mother's, that gives the cell three X chromosomes instead of two. Triple X syndrome occurs because of _______. A. nondisjunction B. point mutations C. crossing over D. deletions 5. The chart below shows the codons that make up the genetic code and the sequence of nucleotides that corresponds to them. A mistake during DNA replication leads to a mutation in the nucleotide sequence shown above. What kind of mutation will result from the mistake made during DNA replication in the nucleotide sequence above? A. a silent mutation B. a frame shift mutation C. a chromosomal mutation D. a nonsense mutation 6. An organism's genotype describes its specific combination of alleles. For example, an Aa genotype is heterozygous for the A allele. An organism's phenotype describes a visible trait, such as tall height, brown eyes, or black fur. How does genotypic variation occur? A. B. C. D. Genotypic variation occurs when alleles are randomly sorted during sexual reproduction. Genotypic variation only occurs during binary fission. Genotypic variation only occurs when genetic mutations occur. Genotypic variation occurs when alleles are randomly sorted during asexual reproduction. 7. The process of meiosis increases genetic variation when genetic information is exchanged during crossing-over and when alleles are independently and randomly assorted into daughter cells. Which of the following processes also contributes to genetic variation? A. cell specialization B. mitotic divisions C. genetic cloning D. random fertilization 8. Down syndrome is a genetic disorder that is typically caused by an extra copy of chromosome 21 in a person's genome. In a small number of cases, however, Down syndrome occurs because a section of chromosome 21 becomes fused onto another chromosome. The type of Down syndrome that occurs because a section of chromosome 21 attaches to another chromosome is an example of a genetic disorder caused by A. a recessive allele. B. a frame shift mutation. C. chromosome deletion. D. chromosome translocation. 9. How do mutations lead to genetic variation? A. by changing the way that the organism reproduces B. by producing random changes in an organism's genetic code C. by changing the organism's behavior D. by changing the organism's appearance 10. Which of the following is a source of genetic variation in sexually-reproducing organisms? A. meiosis B. translation C. mitosis D. all of these 11. ______ is a source of genetic variation that involves the swapping of sections of chromosomes during meiosis. A. Transcription B. Crossing over C. Fertilization D. Translation 12. Errors that are made during DNA replication may result in A. mutations. B. radioactive decay. C. a viral infection. D. identical twins. 13. Organisms are able to reproduce either sexually or asexually. Which of the following statements is true of these reproductive processes? A. B. C. D. During every cell division in asexual reproduction, the number of chromosomes is reduced by half. During every cell division in sexual reproduction, the number of chromosomes is reduced by half. The sorting of genes during sexual reproduction results in a large amount of genetic variation. The sorting of genes during asexual reproduction results in a large amount of genetic variation. 14. The diagram below illustrates a process that can occur during cell division and results in an alteration in the composition of a chromosome. Each letter in the diagram represents a specific gene on the chromosome. The diagram shows that a section of the chromosome was broken out and reinserted backwards. This is known as A. chromosome translocation. B. chromosome deletion. C. chromosome inversion. D. chromosome insertion. 15. What is occurring in this diagram? A. Segments of DNA are crossing over. B. Sister chromatids are separating. C. Genes are replicating. D. Alleles are independently assorting. 16. Most heritable differences are due to A. gene shuffling that occurs during the production of gametes. B. the inability to form proper DNA sequences due to poor nutrition. C. point mutations that occur during mitosis. D. the insertion of incorrect sequences of DNA by faulty polymerases. 17. ______ is a source of genetic variation that refers to a random error in the genetic code. A. Fertilization B. Mitosis C. Meiosis D. A mutation 18. Mutations in genes can occur whenever a segment of DNA is _______. A. substituted B. inserted C. deleted D. all of these 19. A genetic mutation that does not result in a change in the amino acid sequence of the resulting protein is called A. a frame shift mutation. B. a nonsense mutation. C. a chromosomal mutation. D. a silent mutation. 20. During meiosis, diversity is achieved by the process of I. crossing over. II. chromosome separation. III. DNA replication. A. I, II, and III B. II and III only C. I and III only D. I and II only 21. A genetic mutation that causes a codon that should code for a specific amino acid to be changed into a stop codon results in a shortened protein product and is known as A. a nonsense mutation. B. a chromosomal mutation. C. a silent mutation. D. a frame shift mutation. 22. How could an apple farmer increase the number of genotypes and phenotypes present in his next apple crop? A. Cross plants that have very different characteristics. B. Cross plants that have the same characteristics. C. Make genetic clones of plants using asexual reproduction. D. It would be impossible for a farmer to increase the genetic variation of plants. 23. During meiosis, the process of crossing over results in new combinations of alleles due to the fact that A. genetic material is added by a third chromosome during this process. B. genetic material always mutates randomly during this process. C. genetic material is removed during this process. D. genetic material is exchanged between chromosomes during this process. 24. A cat’s coloring is mostly determined by genes on their X chromosomes, which contain alleles for colors, such as black, orange, gray and cream. The allele for white fur is located on a different gene. Calico cats, by definition must display 3 different colors in their fur – white plus two of the other colors. This is easily possible in female cats, because female cats normally possess 2 X chromosomes. However, this occurs rarely in male cats, because males typically possess only 1 X chromosome plus 1 Y chromosome. What must be the genetic make-up of a male calico cat, and what type of chromosomal disorder does this most resemble? A. XXY, Klinefelter's Syndrome B. XYY, Klinefelter's Syndrome C. XX, Down Syndrome D. XO, Turner's Syndrome 25. Gametes in humans are haploid. This means that they have half the number of chromosomes as normal body cells. Sometimes, the gamete of a male and the gamete of a female combine to form a zygote that will eventually turn into a fetus. Phenotypic changes in a fetus may result A. if a mutation occurs in the father's heart cells. B. only if a mutation occurs in both the mother's and father's cells. C. if a mutation occurs in the gametes. D. if a mutation occurs in the mother's brain cells. 26. A frame shift mutation is a genetic mutation that is caused by the insertion or deletion of a specific number of nucleotides that shifts the reading frame of the sequence. The insertion or deletion of how many nucleotides would cause a frame shift mutation? A. 6 B. 2 C. 9 D. 3 27. During normal meiosis, homologous chromosomes pair up and separate so that each gamete receives a copy of every chromosome. Sometimes an error is made during this separation and homologous chromosomes fail to separate. This results in one gamete that has two copies of the chromosome, and another gamete that does not have the chromosome at all. This type of error is known as _______ and usually results in zygotes that either do not develop to term or have severe abnormalities. A. chromosome inversion B. chromosome nondisjunction C. chromosome translocation D. chromosome insertion 28. The chart below shows the codons that make up the genetic code and the sequence of nucleotides that corresponds to them. A mistake during DNA replication leads to a mutation in the nucleotide sequence shown above. What kind of mutation will result from the mistake made during DNA replication in the nucleotide sequence above? A. silent mutation B. nonsense mutation C. chromosomal mutation D. frame shift mutation 29. During meiosis, homologous chromosomes frequently exchange portions of their DNA. This process further increases the number of different genotypes that can appear in an offspring. What is the name of this process? A. crossing-over B. genetic transfer C. transduction D. mutation 30. The chart below shows the codons that make up the genetic code and the sequence of nucleotides that corresponds to them. A mistake during DNA replication leads to a mutation in the nucleotide sequence shown below. This mutation results from the insertion of two nucleotides into the original sequence, which causes the reading frame of the sequence to change. This kind of mutation is known as A. a chromosomal mutation. B. a nonsense mutation. C. a silent mutation. D. a frame shift mutation.