Module 4 IKE & TICA, Questions and answers. 2022/2023. 100% verified. Rated A

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Module 4 IKE & TICA, Questions and answers. 2022/2023. 100% verified. Rated A If you counted 36 chromosomes in the nucleus of a cell, you would expect to see how many chromosomes in the cells pro... duced at the end of mitosis, and how many chromosomes at the end of meiosis. a. 9; 18 b. 18; 36 c. 36; 18 d. 72; 36 e. 36; 36 - ✔✔c. 36; 18 Prophase chromosomes consist of two replicated sister chromatids joined at a centromere. Each sister chromatid contains: a. A single strand of DNA b. A DNA duplex (double-stranded DNA molecule) identical to the other sister chromatid c. A DNA duplex from one parent; its sister chromatid has the homologous DNA duplex from the other parent d. Two DNA duplexes identical to each other e. Two homologous DNA duplexes, one from each parent - ✔✔b. A DNA duplex (double-stranded DNA molecule) identical to the other sister chromatid All of the following are associated with meiosis, except a. crossing over b. duplication of DNA followed by two divisions c. produces gametes d. results in four cells, each identical to the original cell e. homologous chromosomes separating into two cells f. reduction in the chromosome number from diploid to haploid - ✔✔d. results in four cells, each identical to the original cell Meiosis results in the formation of four new nuclei, each with half the chromosomes present in the parental nucleus. What order for the following events best illustrates a sequence of meiosis? - Alignment of pairs of homologous chromosomes in duplicated form at the metaphase plate. - Separation of sister chromatids. - Separation of the homologous chromosomes. - Synapsis; pairs of homologous chromosomes each consisting of two sister chromatids associate with each other indicating that crossing over has occurred. - ✔✔Synapsis; pairs of homologous chromosomes each consisting of two sister chromatids associate with each other indicating that crossing over has occurred. < Alignment of pairs of homologous chromosomes in duplicated form at the metaphase plate. < Separation of the homologous chromosomes. < Separation of sister chromatids. Meiosis results in the formation of four new nuclei, each with half the chromosomes present in the parental nucleus. Which of the steps takes place in both mitosis and meiosis? a. Alignment of pairs of homologous chromosomes in duplicated form at the metaphase plate. b. Separation of sister chromatids. c. Separation of the homologous chromosomes. d. Synapsis; pairs of homologous chromosomes each consisting of two sister chromatids associate with each other indicating that crossing over has occurred. - ✔✔b. Separation of sister chromatids. How many chromosomes are shown below? X a. one unreplicated chromosome b. one replicated chromosome c. two unreplicated chromosomes d. two replicated chromosomes - ✔✔b. one replicated chromosome If the image below represented the entire genome of a particular cell, what would the ploidy of that cell be? X a. haploid (1N) b. diploid (2N) c. triploid (3N) d. tetraploid (4N) - ✔✔a. haploid (1N) If you counted 8 chromosomes in the nucleus of a cell, you would expect to see how many chromosomes in the cells produced at the end of mitosis, and how many chromosomes at the end of meiosis. a. 2; 4 b. 4; 8 c. 8; 4 d. 16; 8 e. 8; 8 - ✔✔c. 8; 4 Successful bone marrow transplants require that the donor and recipient match at their HLA (human leukocyte antigen) genes. HLA proteins are located on the plasma membranes of all cells in the body. There are 3 HLA genes that must be matched: HLA-A, HLA-B, and HLA-C. These genes are highly variable (polymorphic) in the human population; over 2,000 variant alleles are known for each of these genes. The occurrence of matching unrelated donors is at best on the order of 1 in millions, for people with relatively common HLA alleles. Usually, siblings are the most likely to match. Let's think about why this is so. How many different total HLA proteins does a typical person have? Count each allele of HLA-A, HLA-B and HLA-C. - ✔✔6 2 alleles each for HLA-A, HLA-B, and HLA-C. People are diploid and carry two copies of each chromosome (and genes reside on chromosomes). So everyone has two copies of each of the HLA genes, and with so many variant alleles, people are most likely have different alleles at all 3 genes. Jack (HLA-A1, HLA-B35) and Lisa (HLA-A2, HLA-B44) want to know what is the likelihood that another child of theirs will have the same HLA alleles as Molly. HLA-A, HLA-B, and HLA-C are located close together on chromosome 6, so close that there is effectively no crossing over between these genes. Each child will inherit a chromosome 6 from Jack, and a chromsome 6 from Lisa. The figure above shows Lisa Nash's two copies of chromosome 6, and her alles for HLA-A and HLA-B (HLA-C was not typed). What combinations of HLA-A and HLA-B alleles will be present in Lisa Nash's egg cells, and in what proportions? a. 100% B35-A1 b. 50% B35-B44 & 50% A1-A2 c. 50% B35-A1 & 50% B44-A2 d. 100% B44-A2 e. 50% B35-A2 & 50% B44-A1 - ✔✔c. 50% B35-A1 & 50% B44-A2 When Lisa Nash makes new somatic (non-reproductive) cells, those cells have HLA alleles: a. A1 & A2 only b. B35 & B44 only c. Either A1 & B35 or A2 & B44 d. One copy of an A allele and one copy of B allele. e. A1, A2, B35, & B44 - ✔✔e. A1, A2, B35, & B44 Ploidy of a cell is a. the number of chromosomes b. the number of complete chromosome sets c. half the number of replicated chromosomes d. multiples of each chromosome - ✔✔b. the number of complete chromosome sets Mendel's sweet peas have several traits that are inherited with the simple dominance/recessive pattern. Flowers can be white or purple, where purple is dominant to white. If a PP purple homozygote is mated to a pp white homozygote, where in the Punnett square below will you predict heterozygous offspring? a b c d All of these b and c, only. - ✔✔All of these Dominant alleles are more frequent than recessive alleles in a pouplation because a. They exhibit dominance, and so they increase in frequency. b. Recessive alleles cannot spread. c. Recessive can only spread if the dominance is incomplete. d. A and C. e. None of these. Dominant alleles are actually not necessarily more frequent. - ✔✔e. None of these. Dominant alleles are actually not necessarily more frequent. Jack's Chromosome 6s: A3/B41 & A26/B35 When Jack Nash produces sperm, the sperm would have which combinations of the HLA-A and HLA-B genes and in what proportions? a. 100% B5-A26 b. 50% B35-A3 & 50% B41-A26 c. 50% B35-B41 & 50% A3-A26 d. 100% B44-A2 & B35-A26 e. 50% B35-A26 & 50% B41-A3 - ✔✔e. 50% B35-A26 & 50% B41-A3 Lisa: A1/B35 & A2/B44 Jack: A3/B41 & A26/B35 Molly: A26/B35 & A2/B44 Based on HLA alleles, would either Lisa or Jack be a good bone marrow match for Molly? Yes No - ✔✔No Lisa: A1/B35 & A2/B44 Jack: A3/B41 & A26/B35 In the absence of crossing over, which of the following show(s) a possible combination of HLA-A and HLA-B genes in an offspring of Lisa and Jack Nash? Choose all genotypes that are possible for the offspring. Drawing a Punnett square may help answer this and subsequent questions. a. B35, B35, A1, A2 b. B35, B44, A2, A3 c. B44, B35, A2, A26 d. B41, B44, A26, A2 e. B35, B35, A1, A26 f. B41, B44, A2, A3 g. B35, B41, A1, A3 h. B35, B41, A2, A26 - ✔✔c. B44, B35, A2, A26 e. B35, B35, A1, A26 f. B41, B44, A2, A3 g. B35, B41, A1, A3 [Show More]

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