Microsoft Word - Exam 3 Biol101v1

Microsoft Word - Exam 3 Biol101v1 - 1 Exam 3 Biol101-003

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Unformatted text preview: 1 Exam 3 Biol101-003 Name_________________________________________________________________ You have one hour to answer this exam, please read the questions carefully and ask if you do not understand any of them. In the scantron, please mark 1 under K in “Special Codes”. Return both your scantron and this form with your name to me, Good luck! 1) 2) 3) 4) 5) 6) 7) A student in your class makes the following analogy about cell division: cell division is like making a photocopy of the entire blueprint of a completed building and then giving the copied blueprint to another contractor to build a completely new building. Is this an accurate analogy?? a) Yes. Cells replicate their DNA (their blueprint) and then use that newly copied DNA to construct an entire new cell. b) No. A cell does not replicate all of its DNA (their blueprint) prior to cell division; only the DNA that codes for the cellular machinery and structure of that particular cell is copied. c) The analogy is only partially accurate. Cells replicate all of their DNA (the blueprint) prior to cell division, but this DNA is not used to construct an entire new cell. Rather, components of the original parent cell are divided equally between the two daughter cells. d) None of the above What is the relationship between genes and chromosomes? a) Chromosomes are proteins that carry genes made of DNA. b) Genes are the proteins encoded by chromosomes. c) Genes are the proteins around which DNA chromosomes are packaged. d) A chromosome is a DNA molecule with many genes. Meiosis a) allow chromosomes to split in half b) does not change the number of chromosomes c) duplicates the number of chromosomes at the end of the process d) Reduces the number of chromosomes in half e) Will result in two identical cells What is the function of cell division a) To reproduce in single-celled organisms. b) To keep cell size small as multicellular organisms grow. c) To make more cells in a multicellular organism. d) All of the above are functions of cell division. If a cell with 2 nuclei was discovered, which of the explanations below would be true? a) Mitosis occurred without cytokinesis. b) The cell remained in interphase continuously. c) Meiosis and mitosis occurred together. d) Cytokinesis occurred without mitosis. e) None of the above In cell division, when are mitochondria, lysosomes, ribosomes and other cytoplasmic cell components divided between two cells? a) Mitosis b) S c) G2 d) Cytokinesis e) G1 Which cell cycle stage is NOT part of interphase? a) G2 b) M 8) 9) 10) 11) 12) 13) 14) c) G1 d) S After Mitosis, the chromosome number of a daughter cell is the _______ the mother’s cell a) The same as b) One-half c) Rearranged compared to d) Doubled compared to e) b and c One of the main functions of meiosis is to ________. a) produce somatic cells b) produce homologous chromosomes c) reduce the number of chromosomes d) produce gametes e) c and d Interphase a) is the longest phase of the cell cycle b) is characterized by the splitting of the sister chromatids c) is another term for the S stage of the cell cycle d) is the phase in which no cellular metabolic activity is occurring The genetic makeup of an individual is called his/her a) Phenotype b) genotype. c) epistasis. d) recombinant DNA. What is one of the main differences between somatic cells and gametes? a) Gametes undergo meiosis b) Gametes fuse to produce offspring c) Somatic cells in humans have 23 chromosomes d) Human gametes have 23 pairs of chromosomes Mendel postulated that individuals have “elements in pairs” that determine a single phenotype. What are the paired elements? a) Two haploid sets of chromosomes. b) Two alleles of a gene on homologous chromosomes. c) Pairs of sister chromatids. d) Pairs of centromeres. e) A sperm and an egg. Mendel began his experiments with true-breeding parental (P) plants. What did he see when he cross-fertilized P plants that had different traits? a) The F1 plants had new traits that were a blend of P traits. b) All F1 plants had the trait of one or the other P plant. c) The F1 plants had an entirely new trait, not seen in either P plant. d) The F1 plants showed a combination of the two P traits in a 1:1 ratio. e) The F1 plants showed a combination of the two P traits, in a 3:1 ratio. 2 15) If an individual exhibits a recessive trait, which of the following statements must be correct? a) his individual’s genotype is different from an individual with the dominant trait. b) This individual is heterozygous. c) Both parents of this individual had the same genotype for this trait. d) Any siblings of this individual will have the same phenotype for this trait. e) Any children this individual has will always exhibit the trait, regardless of the genotype of the other parent. 16) Assuming that both parent plants in the diagram below are homozygous, why would ¼ of the f2 generation have the green phenotype? 21) 22) 23) 24) a) b) c) 17) 18) 19) 20) because the f1 individuals all are homozygous because the f1 individuals all are heterozygous because the f1 individuals have the same alleles for seed color d) because both parents passed on yellow alleles e) None of the above What are the genotypes of the P generation from question 16? a) Green and yellow b) Homozygous, one dominant, the other recessive c) Heterozygous d) Both homozygous recessive e) a and b Polydactyly is a dominant trait that results in extra fingers and/or toes. Dominant traits a) are the most prevalent in a population. b) require two copies of the dominant allele to express the dominant phenotype. c) produce the dominant phenotype when there is either one copy or two copies of the dominant allele. d) Two of these choices are true. A widow’s peak hairline in humans is dominant to a nonwidow’s peak hairline. If a person has a non-widow’s peak hairline, what is his or her genotype? a) It must be homozygous recessive. b) It is either homozygous dominant or homozygous recessive. c) It must be heterozygous. d) It is either heterozygous or homozygous dominant. e) It must be homozygous dominant. In pea plants, the gene for height has two alleles: tall (T) and short (t). If a homozygous recessive pea plant is crossed with a heterozygous pea plant, what ratio of dominant to recessive phenotypes should occur in the offspring? a) 1:1 b) 3:1 25) 26) 27) 28) 29) c) 4:0 d) 2:1 What gametes can a fly which is homozygous dominant for both body color (G) and wing length (L) pass on to its offspring? a) GGLL b) GgL or GL c) GL d) gL or Gl A, B, and O blood type in humans is controlled by a single A B gene with three alleles: I , I and i. Which of the following are possible genotypes for the parents of a person with type O blood? AB a) I I and ii. AB AB b) I I and I I . A AA c) I i and I I . AA B d) I I and I i . e) None of the above A B, If a person is I I the phenotypes of the parents may be: a) Both are AB b) One can A, the other B c) One can be A, the other O d) Both A e) a, b are a possibility Phenotypic expression of genotype is not influenced by environment. a) True b) False A cell is observed under the microscope. What feature indicates that it has just reached the end of interphase and is entering the M phase? a) A visible contractile ring. b) Two separate cells. c) Elongated, non-condensed chromosomes that are difficult to visualize. d) Chromosomes that are becoming well-defined and visible. Assuming complete dominance, crosses between two dihybrid F1 peas plants, which are offspring from a cross AABB x aabb, result in F2 phenotype ratios of: a) 1:1:1 b) 1: 2: 1 c) 1:3:1 d) 9:3:3:1 From question 25, how many genotypes are expected in the F1 dihybrid plants? a) Two b) Three c) One d) Four Sister chromatids of each chromosome separate during______ a) Meiosis I b) Meiosis II c) Interphase d) Both a and b A duplicated chromosome has ______________ chromatids a) One b) Two c) Three d) Four 3 30) The chromosome number is____________ a) The sum of all chromosomes in a cell of a given type b) An unique characteristic of each species c) Changes after mitosis d) Does not change after mitosis e) a, b and d 31) What structure would be found in dividing plant but not animal cells? a) Sister chromatids b) A mitotic spindle c) A cell plate d) A contractile ring 32) Of the two meiotic divisions, meiosis II is more similar to mitosis. a) True b) False 33) Which of the following statements about meiosis is true? a) Meiosis produces gametes containing chromosomes that are each composed of two chromatids. b) Meiosis produces haploid gametes in which each chromosome has a homologue. c) Meiosis produces haploid cells only after meiosis II has been completed. d) Meiosis produces haploid gametes by separating first homologous chromosomes and then sister chromatids. 34) A certain type of diploid organism has 38 chromosomes. How many chromosomes would a gamete of this organism have? a) 20 chromosomes b) 19 chromosomes c) 76 chromosomes d) 38 chromosomes 35) Which of the following statements applies to a diploid organism whose somatic cells contain 48 chromosomes? a) Its gametes have 12 paired chromosomes. b) Its somatic cells have 24 homologous pairs of chromosomes. c) Its somatic cells have 12 homologous pairs of chromosomes. d) Its gametes have 24 paired chromosomes. 36) If a eukaryotic cell has 20 chromosomes and it undergoes meiosis, how many cells will result and how many chromosomes will they contain? a) 2 cells, each with 10 chromosomes. b) 2 cells, each with 20 chromosomes. c) 4 cells, each with 20 chromosomes. d) 4 cells, each with 10 chromosomes. 37) What is one of the ways that mitosis and meiosis are different? a) DNA is replicated before mitosis but not before meiosis. b) Pairing of homologous chromosomes occurs only in mitosis. c) Recombination (crossing over) occurs only in mitosis. d) There are two chromosome divisions in meiosis and only one in mitosis. e) Mitosis generates genetic variation; meiosis generates exact cell copies. 38) In violets, the B allele produces blue flowers and is dominant to the b allele that produces white flowers, and the C allele produces curly leaves and is dominant to the c allele that produces straight leaves. If a plant was BBCc, which gametes could it produce? a) BBCc b) Bc or BC c) BB or Cc d) C or c e ) BB 39) In violets, the B allele produces blue flowers and is dominant to the b allele that produces white flowers. A blue-flowered violet is crossed with a white-flowered violet, and all the offspring have blue flowers. What were the genotypes of the parent plants? a) BB and BB b) Bb and Bb c) Bb and bb d) BB and bb e) BB and Bb 40) In violets, the B allele produces blue flowers and is dominant to the b allele that produces white flowers, and the C allele produces curly leaves and is dominant to the c allele that produces straight leaves. If you cross Bbcc and BBCc plants, what fraction of the offspring would have white flowers and straight leaves? a) 1/16 b) 1/4 c) 3/16 d) 9/16 e) 0 41) From the cross in the previous question, what fraction of the offspring would have blue flowers and curly leaves? a) 1/16 b) 1/2 c) 3/16 d) 9/16 e) All of them 42) In violets, the B allele produces blue flowers and is dominant to the b allele that produces white flowers, and the C allele produces curly leaves and is dominant to the c allele that produces straight leaves. If you cross bbCc and Bbcc plants, what fraction of the offspring would have blue flowers and straight leaves? a) 1/16 b) 1/4 c) 3/16 d) 9/16 43) Analyze the validity of the two statements below: Statement A: If an individual is heterozygous for a particular gene, it means that the individual carries two different alleles on a set of homologous chromosomes. Statement B: If an individual is heterozygous for a particular gene, half the gametes produced by that individual will contain the dominant allele. a) A) Statement A is TRUE, Statement B is FALSE. b) B) Both statements are TRUE. c) C) Statement A is FALSE, Statement B is TRUE. d) D) Both statements are FALSE. 4 e) 44) Chromosome number is reduced during meiosis because the process consists of a) two cell divisions without any chromosome replication. b) a single cell division without any chromosome replication. c) two cell divisions in which half of the chromosomes are destroyed. d) two cell divisions and only a single round of chromosome replication. e) four cell divisions with no chromosome replication. 45) A person has long fingers (dominant allele). Their genotype is ________. a) SS b) Ss c) ss d) long fingers e) a and b 46) Meiosis leads to variation in offspring by ________. a) producing gametes with all possible combinations of chromosomes b) requiring synapsis before DNA replication c) creating new alleles when mistakes are made in DNA replication d) producing gametes with nonfunctional alleles 47) Meiosis is a reductional division because a) It is shorter b) It does not include metaphase c) The number of chromosomes is doubled d) The number of chromosomes in the daughter cells is half of the mother’s cell A and d 48) Which of the following is a major benefit of crossing over? a) To ensure retention of genetic information, and preserve cell characteristics. b) To bind homologous chromosomes tightly, so they do not accidentally separate. c) To eliminate unused genes by removing them. d) To complete DNA replication. e) To create chromosomes that are a new combination of paternal and maternal material. 49) DNA folded around proteins is called _________ which when condensed form a _________ that when duplicated make 2 __________________ which together are called _________________ a) Chromatin; chromosome; chromatids; sister chromatids b) Chromatin; chromosome; chromatids; non-sister chromatids c) Chromosome; sister chromatids; chromatin; chromatids d) Chromatids; non-sister chromatids; chromosome; chromatin 50) Which of the following statements about mitosis is incorrect? a) It splits up homologous chromosomes. b) It is preceded by duplication of DNA. c) It produces daughter cells with the same number of chromosomes as the original parent cell. d) All of these statements are correct. e) It occurs in somatic cells. 51) Did you write your last name, first name, v-number and exam version in the scantron and your name on this exam? a) Yes b) No c) No entiendo ...
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