BIO 148 Exam 3 Graded A+ New Update

BIO 148 Exam 3 Graded A+ New Update What are sister chromatids? - Answer- They are part of the same replicated chromosome What are non-sister chromatids? - Answer- Describe the relationship between chromatids from homologous chromosomes Advantage of sexual reproduction over asexual reproduction - Answer- Produces offspring with greater heritable variation on which natural selection can act T/f: A replicated chromosome in your body contains DNA sequences inherited from both your parents - Answer- False Which of the following always have identical alleles in diploid cells directly after DNA replication but before they enter meiosis? - Answer- Sister chromatids Why is genetic variation so important? - Answer- If offspring are genetically varied, some will survive better than others in an environment that may randomly change or have new pathogens evolving What are homologous chromosomes? - Answer- Have the same genes in the same locations, but may have different alleles of those genes What are nonhomologous chromosomes? - Answer- They have different genes Sickle cell anemia is caused by a miss ensue mutation in the B globin gene. The normal allele of the B globin gene is located near the left end of chromosome 2. If someone has one normal allele and one mutant allele, where are the two different alleles located? - Answer- One is located on the left end of one chromosome 2, the other is on left end of the homologous chromosome. An organism is 2n=4. During Prophase II of meiosis in this organism, cells will have _ chromosomes and _ DNA molecules - Answer- 2,4 A.diploid organism has 14 chromosomes. Which of the following describes a cell at metaphase II of meiosis in this organism? - Answer- It has no pairs of homologous chromosomes, 14 DNA molecules, and 7 nonhomologous chromosomes Which of the following INCORRECTLY matches a process with the ploidy of the cells before and after the process? - Answer- Meiosis I, 2n, 2n A cell beginning meiosis can have - Answer- 8 chromosomes Which of the following statements about non homologous chromosomes is true - Answer- They contain different dna If a cell with 32 total chromosomes divides by meiosis, how many chromosomes will each nucleus contain after the first cytokinesis (after telophase I)? - Answer- 16 Following the same cell as the page above, how many chromosomes with each nucleus contain after telophase II and cytokines - Answer- 16 How do the chromosomes in a cell produce by meiosis change during the time that the cell develops into a sperm cell? - Answer- They don't If the A and B genes are on different chromosomes, which of the following normal gametes can an individual with the genotype AaBb make? - Answer- AB ab Ab aB If the A and B genes are on different chromosomes and crossing over DOES NOT occur, which of the following normal gametes could be made from ONE germ line cell that undergoes meiosis? - Answer- Ab aB ; AB ab The diploid organism has 10 total chromosomes in each of its somatic cells. If a cell from this organism divides by meiosis, the cells formed meiosis I and cytokinesis will have _ chromosomes and _ DNA molecules - Answer- 5,10 The diploid organism has 10 total chromosomes in each of its somatic cells. How many DNA molecules will each nucleus contain after the second cytokinesis - Answer- 5 The diploid organism has 10 total chromosomes in each of its somatic cells. A zygote produced from the fusion of a sperm and egg from the organism would contain _ chromosomes - Answer- 10 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? - Answer- Homologous chromosomes were present A gene that codes for an enzyme required for black fur pigment is on an auto some. A female dog has two different alleles of the gene, one called A and the other called a. What fraction of her eggs will contain a chromosome with the a allele. - Answer- 1/2 When Mendel crossed pure-breeding yellow-seeded and pure-breeding green-seeded pea plants, all the offspring were yellow seeded. When he took these F1 yellow-seeded plants and crossed them to green-seeded plants, what genotypes ratio is expected? - Answer- 1:1 (.5 yellow and .5 green) A round seeded plant with the genotype Rr is self fertilized and produces offspring. What is the probability that a randomly chosen offspring will make wrinkled seeds? - Answer- .25 Which of the following normal gametes can an individual with the genotype YyRr make? - Answer- YR Yr yR yr Which of the following is true? - Answer- Genes are sequences of DNA nucleotides