5. X and Y chromosomes as homologous pairs: In humans, the XX pairing of the 23rd pair of chromosomes generally gives rise to phenotypic females, while the XY pairing generally gives rise to phenotypic males. Despite having very different shapes and genetic content, the X and Y chromosomes of humans always pair together during meiosis and mitosis. in humans, the gene largely responsible for the male phenotype is the SRY а. gene and it is found on the Y chromosome. However, genetic females (XX) can on occasion have phenotypic traits attributable to the SRY gene. Please explain how this might happen during meiosis. b. Explain why genetic females with genetically encoded male phenotypic traits must (due to the presence of the SRY gene) have received the mutant X chromosome from their father.

5. X and Y chromosomes as homologous pairs: In humans, the XX pairing of the 23rd pair of chromosomes generally gives rise to phenotypic females, while the XY pairing generally gives rise to phenotypic males. Despite having very different shapes and genetic content, the X and Y chromosomes of humans always pair together during meiosis and mitosis. in humans, the gene largely responsible for the male phenotype is the SRY а. gene and it is found on the Y chromosome. However, genetic females (XX) can on occasion have phenotypic traits attributable to the SRY gene. Please explain how this might happen during meiosis. b. Explain why genetic females with genetically encoded male phenotypic traits must (due to the presence of the SRY gene) have received the mutant X chromosome from their father.

Biology: The Unity and Diversity of Life (MindTap Course List)

15th Edition

ISBN:9781337408332

Author:Cecie Starr, Ralph Taggart, Christine Evers, Lisa Starr

Publisher:Cecie Starr, Ralph Taggart, Christine Evers, Lisa Starr

Chapter14: Chromosomes And Human Inheritance

Section: Chapter Questions

Problem 5GP: Human females have two X chromosomes (XX); males have one X and one Y chromosome (XY). a. With...

See similar textbooks

Similar questions

A colleague e-mails you saying that she has identified an interesting chromosome variation at 21q13. In discussing this discovery with a friend who is not a cytogeneticist, explain how you would describe this location, defining each term in the chromosome address 21q13.
Human females have two X chromosomes (XX); males have one X and one Y chromosome (XY). a. With respect to X chromosome alleles, how many different types of gametes can a male produce? b. If a female is homozygous for an allele on an X chromosome, how many types of gametes can she produce with respect to that allele? c. If a female is heterozygous for an X chromosome allele, how many types or gametes can she produce with respect to that allele?
11. The discovery of chromosome banding in eukaryotes has greatly improved our ability to distinguish various cytogenetic events. Particularly useful are “banding" polymorphisms because the "morphs" can be used as chromosome markers. (These morphs are forms of chromosome that are cytologically distinguishable by virtue of minor variations in band size, position, etc). Let's consider chromosome 21 in humans. Assume that one set of parents are: 21°21° (female) x 21°21° (male), where a, b, c and d represent "morphs" of a polymorphism for this chromosome. а, In each case: State the genetic term for the condition (if possible), diagram the event(s) that gave rise to the condition, and state in which individual the event(s) took place. e. 42A + 21a21c + XYY dad MII Interphase [show condensed]: Interphase [show condensed]: Diagram meiosis for After DNA replication: After DNA replication: sex chromosomes in Mom (left) After Meiosis I: and Dad (right) After Meiosis I: Gametes: Gametes: XҮҮ
11. The discovery of chromosome banding in eukaryotes has greatly improved our ability to distinguish various cytogenetic events. Particularly useful are “banding" polymorphisms because the "morphs" can be used as chromosome markers. (These morphs are forms of chromosome that are cytologically distinguishable by virtue of minor variations in band size, position, etc). Let's consider chromosome 21 in humans. Assume that one set of parents are: 21°21 (female) x 21°21ª (male), where a, b, c and d represent "morphs" of a polymorphism for this chromosome. In each case: State the genetic term for the condition (if possible), diagram the event(s) that gave rise to the condition, and state in which individual the event(s) took place. d. 42A + 2121°21° + XX dad MII Interphase [show condensed]: Interphase [show condensed]: Diagram meiosis for After DNA replication: After DNA replication: chromosome 21 in Mom (left) and Dad (right) After Meiosis I: After Meiosis I: Gametes: Gametes: 21 21 21°
4. The diagram below shows the original order of the genes on an autosome in Drosophila: C D EFGHI In each of the chromosomes illustrated below, this original chromosome has undergone a different structural rearrangement. Name the specific type of structural rearrangement that has occurred and draw a diagram to show how each would synapse with the normal chromosome during meiosis. (A) C D EFEFGHIJ (B) C D EIHG FJ (C) C D E F
16. Genetic Variation can occur when homologous chromosomes cross over. What occurs during this process that leads to the genetic variation? (LS3-2) * Corresponding segments of DNA from non-sister chromatids are exchanged. O Two chromatids get tangled, resulting in one re-sequencing its DNA. Two sister chromatids exchange identical pieces of DNA. O Maternal alleles are "corrected" to be like paternal alleles and vice versa.
5. The STR DNA marker DS11 is located on the p arm of the chromosome #8 in humans. Molecular analysis has shown that Charlie Chaplan is heterozygote for the STR marker (genotype DS11A and DS11B). a. Using this knowledge, provide a diagram of meiosis showing only the movements of chromosome 8 (assume no nondisjunction). Throughout, indicate where the marker may be found (in other words, label the chromosome to show where the STR markers can be found. (Show ONLY the chromosomes at interphase, metaphase 1, end of meiosis 1, metaphase 2 and end of meiosis 2). You do not have to show every phase of meiosis.)
5. The STR DNA marker DS11 is located on the p arm of the chromosome #8 in humans. Molecular analysis has shown that Charlie Chaplan is heterozygote for the STR marker (genotype DS11A and DS11B). a. Using this knowledge, provide a diagram of meiosis showing only the movements of chromosome 8 (assume no nondisjunction). Throughout, indicate where the marker may be found (in other words, label the chromosome to show where the STR markers can be found. (Show ONLY the chromosomes at interphase, metaphase 1, end of meiosis 1, metaphase 2 and end of meiosis 2). You do not have to show every phase of meiosis.) b. Suppose Charlie conceived a son with a chromosome 8 trisomy. Molecular analysis of the STR DS11 marker revealed that his son carried two copies of the DS11A marker and a DS11C marker. Based on the data, determine if the nondisjunction occurred in Charlie or in the mother? Provide your reasoning.
9. The unlettered circle at the top of the figure shows a diploid nucleus with four chromosomes that have not yet replicated. There are two pairs of homologous chromosomes, one long and the other short. One haploid set is black, and the other is gray. The circles labeled A to E show various combinations of these chromosomes. Centromere D E A) Which drawing represents prophase of mitosis? B) Which drawing represents one daughter nucleus at the end of telophase of mitosis? 10. Why do neurons and some other specialized cells divide infrequently? A) They no longer have active nuclei. B) They have entered into G0. C) They only have one set of chromosomes. 11. One difference between cancer cells and normal cells is that cancer cells A) are unable to synthesize DNA. B) are arrested at the S phase of the cell cycle. C) continue to divide regardless if they have the appropriate signals. D) cannot function properly because they can only divide when there is space. 12. The spindle checkpoint…
1. A diploid species has 3 pairs of chromosomes in its somatic cells. In males, the first pair is large submetacentric¹; the second is medium acrocentric², and the third is small telocentric³. In females, the first two pairs are like those of the males while the third is large metacentric 45, with satellite Illustrate the karyograms (drawing/picture of the chromosome) of the following: a. A triploid cell in females b. tetrasomic cell in males c. tetraploid cell in females
18. This question refers to the following schematic diagram of two normal chromosomes and five aberrant forms (A through E) of those chromosomes. (Circles represent centromeres and letters represent genetic loci). Which of the aberrant forms represents duplication? Normal Chromosomes (A) (B) | (D) (E)
3. A nondisjunction occurs in the sex chromosomes of a male mouse. What ratio of sex chromosome genotypes would you expect among the gametes in the two following scenarios. Make sure to includethe gamete’s sex chromosome genotype in your genotypic ratio. (A) The nondisjunction of the sex chromosomes occurs only in Meiosis I? (B) The nondisjunction of the sex chromosomes occurs only in Meiosis II?