Mutations in genes that affect meiosis have been identified in many different model organisms. Most of these mutations result in aneuploidy of more than a single chromosome and are nearly sterile. Explain why this is the case.
Q: A certain species of animal has 18 chromosomes in its diploid cells (2n=18). Describe what the…
A: Introduction Strasburger 1875 first reported the presence of chromosomes in eukaryotic cells. The…
Q: At what stage of mitosis can the kind and number of chromosomes be easily detected and determined?
A: As there are four questions given in one, the solution is provided only to the first question.…
Q: An organism has a diploid number of 20 in a primary oocyte. a. How many tetrads are present in the…
A: Oogenesis is a kind of gametogenesis. It produces four haploid gametes (egg) from single parent…
Q: Draw chromosomes in the following cells to represent the various stages of mitosis and meiosis for…
A: When a mother cell splits into two or even more new cells, this is called cell division. Normally,…
Q: Why do you think that organisms do not use the first steps of meiosis (up to and including meiotic…
A: Cell division is the cycle by which a parent cell separates into at least two daughter cells. Cell…
Q: In which meiotic division does the separation of the homologous occur? What are the ploidies of the…
A: Meiosis is a mode of cell division. In this one cell divides to form 4 cells.
Q: During meiosis I, assuming no crossing over, what chromatid combination(s) will be present at the…
A: Meiosis is the cell division of germ cells to produce gametes (sperm or egg cells) in sexually…
Q: Though an individual with abberations such as Robertsonian translocation may be phenotypically…
A: Meiosis is defined as a process where a single cell will divide twice to generate four cells that…
Q: Inversion heterozygotes can have a higher probability of producing gametes that are abnormal in…
A: Organism consisting of an one homolog consisting of inverted Segment while another consists of…
Q: A female gamete is formed after non-disjunction during meiosis. This gamete has the normal haploid…
A: Given: A female gamete is formed after non-disjunction during meiosis. This gamete has the normal…
Q: Give an explanation for why nondisjunction of sex chromosomes is extra nicely tolerated than…
A: Each species has a unique chromosome number, such as 46 for a typical human body cell. This number…
Q: Why is meiosis important? Differentiate it with mitosis. Explain in a detailed manner.
A: The process by which a parent cell divides into two or more daughter cells is known as cell…
Q: Suppose that meiosis occurs in the transient diploid stageof the cycle of a haploid organism of…
A: The synthesis phase involves the replication of DNA for distribution in the daughter cells. It is…
Q: An organism has a diploid number of 16 in a primary oocyte. (a) How many tetrads are present in the…
A: Meiosis causes a reduction in chromosome number by half. It involves the recombination and pairing…
Q: Structurally, meiotic cohesins have different components than mitotic cohesins. This leads to what…
A: The "cell cycle", also known as "cell division", is a set of processes that occur in a cell leading…
Q: On rare occasions, people are born with a condition known as uniparental disomy. It happens when an…
A: Human contains two number of chromosomes 15, one inherited from mother (maternal) and one from…
Q: A cell that has a diploid number of 24 goes through meiosis. How many chromosomes would be in each…
A: There are two types of cell division s observed in Eukaryotes, Mitosis, and Meiosis. Mitosis is…
Q: In a diploid organism, two homologous chromosomes synapse at prophase 1 of meiosis. One of the…
A: Crossing over is the process in which the exchange of genetic material takes place in a cell during…
Q: In Neurospora, his2 mutants require the amino acidhistidine for growth, and lys4 mutants require…
A: Neurospora is a type of a fungus that has axon like striations on its spores. The spores of the…
Q: Describe the events taking place during meiosis? What are the different phases? What is the…
A: Meiosis is a sort of cell division that occurs in sexually reproducing organisms' germ cells and is…
Q: In mice, the Sry gene is located on the Y chromosome very close to one of the pseudoautosomal…
A: The chromosomes are the genetic material present in the nucleus of the cell which is a condensed…
Q: Meiosis is characterized by the pairing of homologous chromosomes during prophase I. In many…
A: Introduction :- Meiosis is the reduction division through in which gametes are formed from parent…
Q: Shown below are photomicrographs of Rhoeo tradescantia cells undergoing meiosis. Answer the…
A: Introduction Mitosis is the division of replicated chromosomes into two new nuclei during the cell…
Q: Describe the cytological observation that suggests that crossing over occurs during the first…
A: The reductional cell division is the meiosis. It happens in two major stages- meiosis I and meiosis…
Q: . A woman with Turner syndrome is found to be colorblind (an X-linked recessive phenotype). Both her…
A: Turner syndrome is a chromosomal disorder that impairs women's development. Half of the sex…
Q: A female gamete is formed after non-disjunction during meiosis. This gamete has the normal haploid…
A: Non-disjunction meiosis is meiosis in which the separation of chromosomes does not occur properly.…
Q: why do the daughter cells produced from meiosis 1 need to divide again in meiosis 2
A: In eukaryotes, two types of cell division occur mitosis and meiosis. Both mitosis and meiosis are…
Q: Crossing-over does not occur between any pair of homologous chromosomes during meiosis in male…
A: During meiosis, crossing over allows recombination of genes between homologous chromosomes. Based on…
Q: A male Drosophila from a wild-type stock is discovered to have only seven chromosomes, whereas…
A: As mentioned the chromosome IV is attached to the distal end (which is farther from the centromere…
Q: Sex chromosome aneuploidy is usually welltolerated because only one X chromosomeremains __________…
A: Step 1 Aneuploidy is the numerical change in the chromosome number in the genome or genomes of an…
Q: How mang sister chromatids are found in a single human cell undergoing Prophase II of Meiosis?
A: Meiosis is a reduction division. Number of chromosomes gets reduced by half in daughter cells.…
Q: Nondisjunction, is when a chromosome does not separate during meiosis. When nondisjunction occurs in…
A: Cell-division is the process by which a parent cell divides and makes two or more daughter cells. It…
Q: Consider a diploid organism in which the somatic cell chromosome number is 42. Assume cytokinesis to…
A: Cell division is an important process which helps to keep the cells growing in number. This enables…
Q: Overall, meiosis and mitosis are analogous processes involving many of the same proteins. However,…
A: Meiosis and mitosis are the two types of cell divisions.
Q: A normal female Drosophila produces abnormal eggs that contain all (a complete diploid set) of her…
A: Although the two mammals and fruit flies produce XX females and XY male, their chromosomes…
Q: A male Drosophila melanogaster has the genotype A/a; B/b; C/c; XD/Y (all genes are on separate…
A: The genotype of a species is its heritable, complete set of genes that are transferred from one…
Q: In humans, males are heterogametic and females are homogametic, Explain. Are there any examples…
A: Answer In humans the 23rd pair of chromosomes contains.
Q: Why do you think that humans with trisomy chromosome 13, 18,or 21 can survive but other trisomies…
A: There are 23 pairs of chromosomes in which 22 pairs are the autosome and 1 pair is sex chromosome.…
Q: Meiotic nondisjunction is much more likely than mitotic nondisjunction.Based on this observation,…
A: Cells are the basic structural and functional unit of the organism. Cell division is the process in…
Q: Genes A and B are on different chromosomes. An individual has the genotype: AaBb You sequence two…
A: Meiosis is the reductional division. during this the chromosome number is reduced to half and from a…
Q: A young couple is planning to have children. Knowing that there have been a substantial number of…
A: Robertsonian translocation is a kind of chromosomal abnormality in which two acrocentric chromosomes…
Q: a. If cell division during gametogenesis is non-meiotic, what is its consequence to the future…
A: A diploid somatic cell undergoes mitosis. a mitotic division results in two daughter cells which are…
Q: What is the mechanism of generating aneuploiding A) Mitotic unequal segregation of…
A: Aneuploids are the individuals whose chromosome number is not a multiple of the haploid number (n).…
Q: Please explain what would be the consequences in successive generations of offspring if the…
A: The genetic content of eukaryotes is found in the nucleus. It is tightly packed and can be seen in…
Q: Are there any factors that can cause an increase in the risk of developing an error in the meiotic…
A: Meiosis is a special kind of cell division employed in the production of haploid gametes . The…
Q: What are the non-random events that occur during sexual reproduction (post-meiosis) in humans?
A: Sexual reproduction is the combination of genes from both male and female parents leading to the…
Q: Assuming all of the chromosomes present during Meiosis II are shown in the figure above, how many…
A: From the given figure, counting homologous pair as two chromosomes, the total number of chromosomes…
Q: What would be the consequences to the outcome of meiosis if SPO11 is absent? Explain your reason.
A: Meiosis is a type of cell division that produces four gamete cells by halving the number of…
Oogenesis
The formation of the ovum (mature female gamete) from undifferentiated germ cells is called oogenesis. This process takes place in the ovaries (female gonads). Oogenesis consists of three stages known as the multiplication phase, growth phase, and maturation phase.
Cell Division
Cell division involves the formation of new daughter cells from the parent cells. It is a part of the cell cycle that takes place in both prokaryotic and eukaryotic organisms. Cell division is required for three main reasons:
- Mutations in genes that affect meiosis have been identified in many different model organisms. Most of these mutations result in aneuploidy of more than a single chromosome and are nearly sterile. Explain why this is the case.
Trending now
This is a popular solution!
Step by step
Solved in 3 steps
- Shown below are photomicrographs of Rhoeo tradescantia cells undergoing meiosis. Answer the following question for each of the photomicrographs: Identify the cytogenetic abnormality observed (ex. ring, chain, laggard, bridge). Identify the meiotic stage in which these aberrations are observed (as shown in the photomicrograph). Explain how these aberrations are formed and relate to the possible causal mutation(s). Will this result to sterile and/or fertile gametes? Explain.A diploid organism produces four gametes from one parent cell through the process of meiosis. Two gametes are found to have 7 chromosomes and two gametes are found to have 5 chromosomes. A) Is this the expected number of chromosomes that would be found in each gamete following a normal cycle of meiosis? If yes, explain why. If no, explain why not and describe how the gamete situation described above occurred. B) Determine the number of homologous chromosome pairs that the original parent cell contained, before meiosis began. Explain how you determined this value.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=16 384
- Meiosis is characterized by the pairing of homologouschromosomes during prophase I. In many species, an elaboratestructure called the synaptonemal complex forms betweenhomologues. During this pairing, homologues may exchangechromosomal material at sites called chiasmata. In meiosis I, thehomologues separate from each other, reducing the chromosomenumber to the haploid state (thus the reductive division). It isfollowed by a second division without replication, during whichsister chromatids become separated. The result of meiosis I and IIis four haploid cells. If sister chromatids separated at the first division, would meiosis still work?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 (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 384A heterozygous diploid yeast Aa Bb went through meiosis. What percentage of the haploid spores will have recombinant combinations of alleles? What if genes A and B are unlinked? Explain What is genes A and B are linked? Explain
- You are investigating two temperature-sensitive mutant cells. In one, you can inactivate shugoshin activity by raising the temperature slightly at the start of meiosis. In the other, you can similarly inactivate separase activity by raising the temperature. How would the two cells be affected by inactivating these proteins?Somatic cells in organisms of a certain diploid plant species normally have 14 chromosomes. The chromosomes in the gametes are numbered from 1 through 7. Rarely, zygotes are formed that contain more or fewer than 14 chromosomes. A zygote that has the chromosome composition 111 22 33 44 555 66 77 is 1. A.) Anueploid or B.)Euploid , and its chromosome complement can be described as 2. A). trisomic , B.)allotriploid , C. autotriploid for chromosomes 1 and 5. Pick the correct letter for 1 and 2.We have discussed meiosis in yeast. One ascus e one melotic event. Two haploid yeast strains are crossed together, one wild type, the other mutant for 2 linked genes. The resulting diploid strain undergoes melosis eventually (=many meiotic events > many asci). A. What will the results be if the 2 genes are very far away from each other (certainly more than 50 map units)? B. What will the results be if the two genes are right next to each other, "no distance at all, zero distance"? (Explain your answers). Results here are patterns of asci and their percentages. Like for example "50% tetratypes, 0% ditypes", etc. If you forgot what a ditype or a tetratype is, you can illustrate them like that.
- Sketch a series of diagrams showing each of the following, making sure to end each series with haploid cells:(a) How a pair of alleles for a single locus segregate in meiosis(b) How the alleles of two unlinked loci assort independently in meiosis(c) How the alleles of two linked loci undergo genetic recombinationOne reason that worker bees forgo their own reproduction to help their sister (the queen) reproduce is that female bees are more closely related to their sisters than they are to their own offspring. This quirk of genetics results from the fact that bees have haplodiploid sex determination, in which females are diploid, with a mother and a father, but males are haploid, developing from unfertilized eggs. Because males are haploid, they produce sperm by mitosis. Explainwhy haplodiploid sex determination causes females to be more closely related to their sisters than to their offspring.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 PORYZ