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On rare occasions, people are born with a condition known as uniparentaldisomy. It happens when an individual inherits both copies of a chromosome from one parent and no copies from the other parent. This occurs when two abnormal gametes happen to complement each other to produce a diploid zygote. For example, an abnormal sperm that lacks chromosome 15 could fertilize an egg that contains two copies of chromosome 15. In this situation, the individual has maternal uniparentaldisomy 15 because both copies of chromosome 15 were inherited from the mother. Alternatively, an abnormal sperm with two copies of chromosome 15 could fertilize an egg with no copies. This is known as paternal uniparentaldisomy 15. If a female is born with paternal uniparentaldisomy 15, would you expect her to be
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Genetics: Analysis and Principles
- Human sex chromosomes are XX for females and XY for males. a. With respect to an X-linked gene, how many different types of gametes can a male produce? b. If a female is homozygous for an X-linked allele, how many different types of gametes can she produce with respect to this allele? c. If a female is heterozygous for an X-linked allele, how many different types of gametes can she produce with respect to this allele?arrow_forwardInfants born with Patau syndrome have an extra copy of chromosome 13, which leads to developmental abnormalities such as cleft lip and palate, small eyes, and extra fingers and toes. Another type of genetic disorder, Turner syndrome, results from the presence of only one sex chromosome—an X chromosome. Individuals born with one X chromosome are females exhibiting few noticeable defects until puberty, when they fail to develop normal breasts and internal sexual organs. what is more information about these genetic diseases on how they relate and differ?arrow_forwardInfants born with Patau syndrome have an extra copy of chromosome 13, which leads to developmental abnormalities such as cleft lip and palate, small eyes, and extra fingers and toes. Another type of genetic disorder, Turner syndrome, results from the presence of only one sex chromosome—an X chromosome. Individuals born with one X chromosome are females exhibiting few noticeable defects until puberty, when they fail to develop normal breasts and internal sexual organs. what is more information about these genetic diseases on how they relate and differ? What are the meiotic events that could lead to the birth of an individual with either Patau syndrome or Turner syndrome as shown above?arrow_forward
- Butterflies have an X-Y sex-determination system that is different from that of flies or humans. Female butterflies may be either XY or X0, while butterflies with two or more X chromosomes are males. This photograph shows a tiger swallowtail gynandromorph, which is half male (left side) and half female (right side). Given that the first division of the zygote divides the embryo into the future right and left halves of the butterfly, propose a hypothesis that explains how nondisjunction during the first mitosis might have produced this unusual-looking butterfly. Question is also in the picture.arrow_forwardIn humans, each cell normally contains a diploid (2n) chromosome number of 46. Say that a human body cell and sex cell will undergo mitosis and meiosis respectively, provide the number of chromosomes in each cell for every stage. Stage of Mitosis Number of Stages of Meiosis Number of Chromosomes in Chromosomes in One Cell One Cell Prophase 2n = Prophase 1 2n = Prometaphase 2n = Prometaphase 1 2n = Metaphase 2n = Metaphase 1 2n = Anaphase 2n = Anaphase 1 2n = Telophase and Cytokinesis Telophase 1 and Cytokinesis 2n = n = Prophase 2 Prometaphase 2 n = Metaphase 2 n = Anaphase 2 = u Telophase 2 and Cytokinesis n =arrow_forwardDuring 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 (2n=4) . 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 22 or 4.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 23 or 8. In an organism with a haploid number of 7, how many possible combinations of maternal and paternal chromosomes can occur in its gametes? a. 72=49 b. 27=128 c.17=1 d. 214=16 384arrow_forward
- true or false, In meiosis, the haploid set of chromosomes is created in the reduction phase but they become single-stranded in the division phase?arrow_forwardA cell has four pairs of chromosomes. Assuming that crossing over does not occur, what is the probability that a gamete will contain all of the paternal chromosomes? If n equals the number of chromosomes in a set, which of the following expressions can be used to calculate the probability that a gamete will receive all of the paternal chromosomes: (1/2)n, (1/2)n–1, or n1/2?arrow_forwardMeiosis is also known as reduction cell division because it reduces the ploidy level from diploid (2n) to haploid (n). Why do we need to reduce our ploidy level in certain cells?arrow_forward
- A man who is a carrier of a translocated 15/21 chromosome marries a genotypically normal woman. (1). Show the possible gametes that will be formed by this man if the translocated 15/21 chromosome synapses with chromosome 21 at Prophase I. (2). What is the probability that the first child of the couple will be a phenotypically normal girl? (3). What is the probability that the first child of the couple will be a genetically normal boy?arrow_forwardFrom 2 to 6 percent of people with autism have an extra chromosome that consists of two long arms of chromosome 15. It includes two copies of the chromosome 15 centromere. Two normal copies of the chromosome are also present. What type of chromosome abnormality in a gamete can lead to this karyotype, which is called isodicentric 15?arrow_forwardA phenotypically normal woman has an abnormally structured chromosome 2, along with a normal homologue. She marries a phenotypically normal man with an abnormally structured chromosome 16 and a normal homologue. What is the probability of their child will have an abnormal chromosome 2 and 16? What is the probability that this child, having inherited both abnormal chromosomes, will now pass both abnormal chromosomes to its children?arrow_forward
- Human Biology (MindTap Course List)BiologyISBN:9781305112100Author:Cecie Starr, Beverly McMillanPublisher:Cengage LearningHuman Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage Learning