Concept explainers
Kuliev and Verlinsky (2004) state that there was a relatively high number of separation errors at meiosis I. In these cases the centromere underwent a premature division, occurring at meiosis I rather than meiosis II. Regarding chromosome 21, what would you expect to be the chromosome 21 complement in the secondary oocyte in which you saw a single chromatid (monad) for chromosome 21 in the first polar body? If this secondary oocyte was involved in fertilization, what would be the expected consequences?
Want to see the full answer?
Check out a sample textbook solutionChapter 2 Solutions
Concepts of Genetics (12th Edition)
Additional Science Textbook Solutions
Anatomy & Physiology (6th Edition)
Human Anatomy & Physiology (Marieb, Human Anatomy & Physiology) Standalone Book
Genetic Analysis: An Integrated Approach (3rd Edition)
Genetics: From Genes to Genomes, 5th edition
Genetics: From Genes to Genomes
Campbell Essential Biology with Physiology (5th Edition)
- Variations in Chromosome NumberAneuploidy Describe the process of nondisjunction and explain when it takes place during cell division.arrow_forwardThe diagram below shows a cell during Meiosis II: a) What phase of Meiosis II is the cell in? How do you know? b) Assuming all of the chromosomes present during Meiosis II are shown in the figure above, how many chromosomes (counting homologous pairs as two chromosomes) does a gamete from this organism have? c) Draw the same cell during the same phase of Meiosis I. Label the elementsarrow_forwardConsider and individual with 3 pairs of homologous chromosomes labeled as: A/a B/b D/d(where the slash line separates one chromosome from its homologues). How many differentmeiotic products (sperm or egg) can this individual produce? What are these?arrow_forward
- During metaphase I of meiosis, tetrads align along the metaphase plate independently of each other. Therefore, there is a random “shuffle” of maternal and paternal chromosomes in the resulting gametes.The following diagram demonstrates how this works in a diploid cell with four chromosomes . Because there are two pairs of chromosomes and each pair can align in one of two ways during metaphase I, the number of possible variations in the gametes produced is , or .For an organism that is , there are three pairs of chromosomes, so the number of possible variations in the gametes produced due to independent assortment in metaphase I is , or . In an organism with a haploid number of , how many possible combinations of maternal and paternal chromosomes can occur in its gametes? Select one: a. 72=49 b. 27=128 c.17=1 d. 214=16 384arrow_forwardAssume that you were examining a first polar body and noted that it had one copy (dyad) of each chromosome except chromosome 21. Chromosome 21 was completely absent. What would you expect to be the chromosome 21 complement (only with respect to chromosome 21) in the secondary oocyte? What consequences are likely in the resulting zygote if the secondary oocyte was fertilized?arrow_forwardA diploid cell has 15 picograms of DNA in G₁ phase. If this cell is a germ line cell that undergoes meiosis, how much DNA will each daughter cell contain at the end of meiosis I? How much DNA will each daughter cell contain at the end of meiosis II? MI = 30 pg: MII = 15 pg O MI = 15 pg; MII = 15 pg MI = 7.5 pg; MII = 15 pg O MI = 15 pg: MII = 7.5 pgarrow_forward
- A diploid species has 3 pairs of chromosomes in its somatic cells. In males, the first pair is large submetacentric[1]; the second is medium acrocentric[2], and the third is small telocentric[3]. In females, the first two pairs are like those of the males while the third is large metacentric[4][5], with satellite4 Illustrate the karyograms (drawing/picture of the chromosome) of the following: A triploid cell in females tetrasomic cell in males tetraploid cell in females [1] submetacentric --centrosome is just above the middle of the chromosome [2] acrocentric --centrosome is much higher location than submetacentric so that the “p” arm of the chromosome is much shorter than the q arm [3] telocentric --the centromere is at the end of the chromosome [4] metacentric --centrosome is in the middle of the chromosome; thus the “p-arm” and the “q-arm” or both arms of the chromosome are equal in length [5] satellite-a constriction in an arm of a chromosome, aside…arrow_forwardIn fruit flies, chromosomal crossing over does not occur in meiosis in males, whereas crossing over does occur in meiosis in females. In fruit flies that are heterozygous at many genes (i.e. many maternal and paternal versions of the genes differ), at what stage would cells no longer be heterozygous for any gene during the process of meiosis? a)After the second meiotic division in males, and after the first meiotic division in females. b)After the second meiotic division in both males and females. c)After the first meiotic division in both males and females. d)After the first meiotic division in males, and after the second meiotic division in females.arrow_forwardMatch the following: A duplicated chromosome is made of 2.A maternal and paternal chromosome present together, each with two sister chromatids 3.Semi-condensed DNA made up of coiled nucleosomes. 4.Super-coiled DNA strands. 5.Contains only one copy of each chromosome. 6.Name of an error during meiosis resulting in fewer chromosomes than normal in a zygote or individual (2n-1) 7.General term for an error resulting in the incorrect number of chromosomes in a gamete after meiosis 8.A specific version of a gene, such as blue eye colour 9.A region on a chromosome that codes for a protein 10.Region where chromosomes are attached 11.None of the above (should be selected more than once) with monosomy trisomy aneuploidy centromere gene sister chromatids diploid Haploid tetrad telomere Chromosomes Chromatin allelearrow_forward
- Consider a cell with 2 pairs of homologous chromosomes where Chromosome 1 with genes VWXYZ is the homolog of Chromosome 2 with genes vwxyz while Chromosome 3 with genes PQRST is the homolog of Chromosome 4 with genes parst. If a reciprocal translocation occurred between Chromosome 1 YZ genes and Chromosome 3 ST genes, give the following gamete types produced after meiosis: (Answer in Arabic numbers only) 1. Gamete/s with non-recombinant chromosomes 2. Gamete/s with 1 recombinant chromosome 3. Gamete/s with 2 recombinant chromosomes 4. Gamete/s with gene duplications 5. Gamete/s with gene deletions 6. Gamete/s with 2 normal chromosome sequences 7. Gamete/s with 1 normal chromosome sequence 8. Gamete/s with balanced translocation 9. Gametes/ with all dominant genes 10. Gamete/s with all recessive genes 11. Gamete/s with 10 different genes 12. Gamete/s with TSXWV genes 13. Gamete/s with vwxyz genes 14. Gamete/s with pqrst genes 15.Gamete/s with PORYZarrow_forwardin metaphase 1 of meiosis, the homologous chromosomes line up side by side along the equator so that crossing over can occur between the homologous pairs and the homologous chromosomes can be pulled to opposite poles during anaphase 1. in mitosis, by contrast, homologous chromosomes line up single file along the equator. what benefits are derived from these two different ways that homologous chromosomes are positioned at metaphase in meiosis and mitosis?arrow_forwardFor an organism with 3 pairs of chromosomes (6 total chromosomes, 2n = 6), draw chromosome diagrams for the following phases of meiosis: prophase I, metaphase I, anaphase I, telophase I, prophase II, metaphase II, anaphase II & telophase II. Be sure to draw the correct number of chromosomes and the correct number of chromatids per chromosome. Use a different color to represent each chromosome type (for example, use blue to indicate all copies of chromosome 1, red for all copies of chromosome 2, and green for all copies of chromosome 3).arrow_forward
- Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage Learning