A female gamete is formed after non-disjunction during meiosis. This gamete has the normal haploid complement of autosomes but lacks any sex chromosomes. This gamete fuses with a normal male gamete containing a haploid autosome set and a single X chromosome. i. If these were human gametes, what would the sex of the resulting zygote be? Justify your answer. ii. If this occurred in Drosophila, what would the sex of the resulting fly be? Justify your answer.

A female gamete is formed after non-disjunction during meiosis. This gamete has the normal haploid complement of autosomes but lacks any sex chromosomes. This gamete fuses with a normal male gamete containing a haploid autosome set and a single X chromosome. i. If these were human gametes, what would the sex of the resulting zygote be? Justify your answer. ii. If this occurred in Drosophila, what would the sex of the resulting fly be? Justify your answer.

Biology Today and Tomorrow without Physiology (MindTap Course List)

5th Edition

ISBN:9781305117396

Author:Cecie Starr, Christine Evers, Lisa Starr

Publisher:Cecie Starr, Christine Evers, Lisa Starr

Chapter8: How Cells Reproduce

Section: Chapter Questions

Problem 2.2DID

See similar textbooks

Similar questions

A female gamete is formed after non-disjunction during meiosis. This gamete has the normal haploid complement of autosomes but lacks any sex chromosomes. This gamete fuses with a normal male gamete containing a haploid autosome set and a single X chromosome.i. If these were human gametes, what would the sex of the resulting zygote be? Justify your answer. ii. If this occurred in Drosophila, what would the sex of the resulting fly be? Justify your answer.
A male gamete is formed after non-disjunction during meiosis. This gamete has the normal haploid complement of autosomes but contains both the X and Y chromosomes. This gamete fuses with a normal female gamete containing a haploid autosome set and a single X chromosome.i. If this occurred in Drosophila, what would the sex of the resulting fly be? Justify your answer.ii. If these were human gametes, what would the sex of the resulting zygote be? Justify your answer.
A sperm cell from the fruit fly Drosophila melanogaster contains four chromosomes. How many chromosomes would be present in a spermatogonial cell about to enter meiosis? How many chromatids would be present in a spermatogo- nial cell at metaphase I of meiosis? How many would be present at metaphase II?
There are 56 chromosomes in a mature elephant cell. If one of the elephants cells responsible for gamete production undergoes meiosis, how many chromosomes would be present in each cell after meiosis I, and then after meiosis II.
In kangaroos, the somatic cells are diploid, having 22 chromosomes. How many chromosomes are present in each cell at metaphase II of meiosis?
A male Drosophila melanogaster has the genotype A/a; B/b; C/c; XD/Y (all genes are on separate chromosomes). How many different sperm genotypes can it produce through meiosis of one single pre-gametic (2n) cell? (remember, there is no crossing over in male Drosophila) Explain.
A mature female tiger, with 38 diploid chromosomes in each somatic cell, produces haploid oocytes (egg cells) with how many chromosomes per cell? A. 18 autosomes, and 1 sex-determining chromosome (Y) B. 36 autosomes, and 2 sex-determining chromosomes (XX) C. 18 autosomes, and 1 sex-determining chromosome (X) D. 34 autosomes, and 2 sex-determining chromosomes (XY) E. 17 autosomes, and 1 sex-determining chromosome (X)
In Drosophila, the X chromosomes may become attached to one another (XXn ) such that they always segregate together. Some flies thus contain a set of attached X chromosomes plus a Y chromosome. (a) What sex would such a fly be? Explain why this is so. (b) Given the answer to part (a), predict the sex of the off-spring that would occur in a cross between this fly and a normal one of the opposite sex. (c) If the offspring described in part (b) are allowed to interbreed, what will be the outcome?
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 of gametes can she produce with respect to that allele?
In human spermatogenesis, mitosis of a stem cell gives rise to one cell that remains a stem cell and one cell that becomes a spermatogonium. (a) Draw four rounds of mitosis for a stem cell, and label the daughter cells. (b) For one spermatogonium, draw the cells it would produce from one round of mitosis followed by meiosis. Label the cells, and label mitosis and meiosis. (c) Explain what would happen if stem cells divided like spermatogonia.
Consider the following two meiocytes in metaphase I, with crossover positions as indicated for cell A. Solid black lines indicate spindle microtubules. Assume blue chromosomes represents paternal chromosomes and green maternal chromosomes. i) How many chromosomes and chromatids were present in cell A during the G1 phase? Please clearly specify chromosomes and chromatids in your answer. ii) For cell A, list all the gametes that will be produced from this cell. Give the alleles of each gamete contained within a set of brackets. You may ignore independent assortment.iii) For cell B, list all the gametes that will be produced from this cell given crossing over. Give the alleles of each gamete contained within a set of brackets. You may assume that no crossing over would take place.
Crossing-over does not occur between any pair of homologous chromosomes during meiosis in male Drosophila. From what you have learned about meiosis and crossing-over, propose one hypothesis for why this might be the case.