BIO 148 Exam Questions With 100% Correct Answers | Verified | Latest Update

BIO 148 Exam Questions With 100% Correct Answers | Verified | Latest Update Evolution can be defined as Individuals becoming better adapted whenever the environment changes Only the fittest survive One species changing into another Genetic change over time within a population - Answer- Genetic change over time within a population For evolution to occur, which of the following is/are necessary? I. Heritable variation II. Selection III. Environmental change I, II, and III II only I and II I only - Answer- I only Which of the following mutations is most likely to increase fitness? A silent mutation in an essential gene A frameshift mutation in the gene that encodes DNA polymerase A missense mutation that increases activity of an enzyme - Answer- A missense mutation that increases activity of an enzyme A mutation that confers antibiotic resistance to bacteria occurs in a large population of bacteria growing in a test tube without antibiotic. The same mutation occurs in a bacterial population growing in the presence of an antibiotic. After many generations, the number of antibiotic resistant bacteria in the tube without antibiotic is: much lower than the number in the tube containing antibiotic about the same as the number in the tube containing antibiotic impossible to determine - Answer- much lower than the number in the tube containing antibiotic Which evolutionary force is the slowest to change allele frequencies on its own? mutation natural selection gene flow genetic drift - Answer- mutation An individual that is heterozygous for a particular gene has ____________. Two identical alleles of the gene, with each copy located on different non-homologous chromosomes Two different alleles of the gene, with each copy located on different non-homologous chromosomes Two different alleles of the gene, with each copy located on homologous chromosomes Two identical alleles of the gene, with each copy located on homologous chromosomes - Answer- Two different alleles of the gene, with each copy located on homologous chromosomes Which of these descriptions correctly describes metaphase II of meiosis? Cell is diploid, chromosomes line up in center Cell is haploid, chromosomes line up in center Cell is haploid, sister chromosomes separate Cell is diploid, homologs pair Cell is haploid, homologs pair - Answer- Cell is haploid, chromosomes line up in center A cell that is the product of meiosis II and cytokinesis contains the chromosomes shown below. Which of the following would be present in the sperm that develops from this cell? - Answer- b. You have isolated a single cell from a diploid organism. Which of the following would indicate that the cell was at metaphase of meiosis I and NOT metaphase of meiosis II? There was only one copy of each type of chromosome All the chromosomes were composed of one chromatid All the chromosomes were composed of two chromatids Homologous chromosomes were present It has a metaphase plate - Answer- Homologous chromosomes were present The A and B genes are on the same chromosome. A zygote is formed by the fusion of a gamete with the genotype aB and a gamete with the genotype Ab. Which of the following accurately depicts the chromosome content of the zygote right after fertilization occurs? - Answer- d. The diploid organism Biologica isawesema has 10 TOTAL chromosomes in each of its body (somatic) cells. If a cell from this organism divides by meiosis, the cells formed by meiosis I and cytokinesis will have _____ CHROMOSOMES and _____ DNA MOLECULES. 10, 10 5, 10 5, 5 20, 20 10, 20 - Answer- 5, 10 The diploid organism Biologica isawesema has 10 TOTAL chromosomes in each of its body (somatic) cells. How many DNA molecules will each nucleus contain after the second cytokinesis (after telophase II)? 40 20 10 5 - Answer- 5 The diploid organism Biologica isawesema has 10 TOTAL chromosomes in each of its body (somatic) cells. A zygote produced from the fusion of a sperm and egg from Biologica isawesema would contain _____ CHROMOSOMES. 5 40 10 20 - Answer- 10 The advantage of sexual reproduction over asexual reproduction is that sexual reproduction _____________. guarantees that both parents will provide care for each offspring allows animals to conserve resources and reproduce only during optimal conditions produces offspring with greater heritable variation on which natural selection can act enables males and females to remain isolated from each other while rapidly colonizing habitats yields more numerous offspring more rapidly than is possible with asexual reproduction - Answer- produces offspring with greater heritable variation on which natural selection can act The cells below come from the same organisms. Each is at a different stage of meiosis. The diploid number for this organism is ____. 12 6 24 3 - Answer- 6 How does meiosis relate to sexual reproduction? meiosis produces germline cells that develop into offspring meiosis produces haploid cells that develop into gametes that unite during fertilization meiosis produces somatic cells that develop into an animal's body meiosis produces zygotes that develop into offspring meiosis is not related to sexual reproduction - Answer- meiosis produces haploid cells that develop into gametes that unite during fertilization Which of the following describes the difference between genotype and phenotype? genotype describes genetic content whereas phenotype describes an observable characteristic genotype can be homozygous or heterozygous whereas phenotype is always heterozygous genotype can be homozygous or heterozygous whereas phenotype is always homozygous phenotype describes genetic content whereas genotype describes an observable characteristic both genotype and phenotype can be homozygous or heterozygous - Answer- genotype describes genetic content whereas phenotype describes an observable characteristic The A and B genes are on nonhomologous chromosomes. A zygote is formed by the fusion of a sperm with the genotype aB and an egg with the genotype Ab. The zygote develops into a male. Which of the following are genotypes of sperm that could be produced by this male? only Ab aB and Ab only aB AB and ab AB, ab, Ab and aB - Answer- AB, ab, Ab and aB The body cells of a privet shrub (plant) each contain 46 chromosomes. How do privet chromosomes differ from the 46 human chromosomes? A. Genes on a particular privet chromosome must be on a different chromosome in humans C. Privets and humans have many different genes that encode different proteins B. Privet cells have the same genes as humans, but express different genes (different subsets of genes are transcribed and translated) - Answer- C. Privets and humans have many different genes that encode different proteins How are the chromosomes that are present in unrelated individuals of the same species different from each other? C. Unrelated individuals have the same number of chromosomes but the alleles on the chromosomes are different. B. Unrelated individuals have the same number of chromosomes but the genes on the chromosomes are different A. Unrelated individuals have different numbers of chromosomes and the genes on the chromosomes are different. - Answer- C. Unrelated individuals have the same number of chromosomes but the alleles on the chromosomes are different. A replicated chromosome contains DNA sequences inherited from both parents False True - Answer- False An individual has the genotype Aa for a particular gene at a particular locus. After DNA replication but before meiosis, what will the individual's chromosomes that carry these genes most resemble? - Answer- b. In anaphase I of meiosis Sister chromatids move toward opposite poles Homologs move toward the same pole Crossing over takes place Homologous chromosomes move toward opposite poles - Answer- Homologous chromosomes move toward opposite poles