Controlling the overgrowth of invasive aquatic vegetation is a significant problem in the waterways of most U.S. states. Originally, herbicides and dredging were used for control, but in 1963, diploid Asian carp were introduced in Alabama and Arkansas. Unfortunately, through escapes and illegal introductions, the carp spread rapidly and became serious threats to aquatic ecosystems in 45 states. Beginning in 1983, many states began using triploid, sterile grass carp as an alternative, because of their inability to reproduce, their longevity, and their voracious appetite. On the other hand, this genetically modified exotic species, if not used properly, can reduce or eliminate desirable plants and outcompete native fish, causing more damage than good. The use of one exotic species to control other exotic species has had a problematic history across the globe, generating controversy and criticism. Newer methods for genetic modification of organisms to achieve specific outcomes will certainly become more common in the future and raise several interesting questions.
Why would the creation and use of a tetraploid carp species be unacceptable in the above situation?
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Concepts of Genetics (12th Edition)
- The radish (Raphanus sativus) has a diploid number (2n) of 18. The cabbage (Brassica oleracia) also has a diploid number (2n) of 18. Why is it that if you cross these two species to produce a hybrid with a total of 18 chromosomes in its somatic cells it is sterile, but if you form an allotetraploid (also known as amphidiploid) from these two species it is fertile?arrow_forwardIn a particular country in sub-Saharan Africa, a medical study revealed that 0.075% of the country's population are suffering from sickle-cell anemia. Sickle cell disease is caused by a mutation in the haemoglobin-Beta gene found on chromosome 11. Sickle cell anemia is controlled by a pair of alleles, H and h, where the individuals with the illness have the homozygous recessive genotype; those with normal red blood cells have the alternative genotype. Using the Hardy-Weinberg's equation, calculate the percentage of the population of the two genotypes for normal blood cells. In a few remote areas in that country, the percentage of sickle cell anemia reaches as high as 5%. Calculate the percentage of homozygous and heterozygous individuals with the normal blood cells and find the ratio for both phenotypes.arrow_forwardA diploid organism has a total of 14 chromosomes and about20,000 genes per haploid genome. Approximately how manygenes are in each linkage group?arrow_forward
- In a diploid plant species, an F1 with the genotype Mm Rr Ss is test crossed to a pure breeding recessive plant with the genotype mm rr ss. The offspring genotypes are as follows: Genotype Number Mm Rr Ss 687 Mm Rr ss 5 Mm rr Ss 68 Mm rr ss 196 mm Rr Ss 185 mm Rr ss 72 mm rr Ss 8 mm rr ss 679 Total 1900 1. What is the gene order of these linked genes?arrow_forwardIn a sample of 1000 patients with Down syndrome, a geneticist discovers that 95% of them are trisomic, while 5% have diploid number of chromosomes. Explain this discrepancy.arrow_forwardIn barley, a self-fertilizing species that can be cross-fertilized, two true-breeding strains with virescent leaves occur. In strain A, the trait is caused by a cytoplasmic gene while in strain B it is by a recessive chromosomal gene. What phenotypes would you expect among the progeny, and in what proportions in each of the following? Illustrate your crosses below, indicate and the female and male parent for each cross, and write the phenotype of all the parents and offspring(s). a. reciprocal crosses between A and Bb. crossing of each F1 in (a) to each of the paternal strainsc. self-fertilization of the F1’s in (a)d. reciprocal crosses between F1’s in (a) Use the following gene assignments: Strain A (trait is in Cytoplasm) A – virescent a – not virescent Strain B (recessive chromosomal gene) B – not virescent b - virescentarrow_forward
- In barley, a self-fertilizing species that can be cross-fertilized, two true-breeding strains with virescent leaves occur. In strain A, the trait is caused by a cytoplasmic gene while in strain B it is by a recessive chromosomal gene. What phenotypes would you expect among the progeny, and in what proportions in each of the following? Illustrate your crosses below, indicate and the female and male parent for each cross, and write the phenotype of all the parents and offspring(s). a. reciprocal crosses between A and Barrow_forwardA kidney-bean shaped eye is produced by a recessive gene, k, on the third chromosome of Drosophila. Orange eye color, called cardinal, is produced by the recessive gene cd on the same chromosome. A third recessive gene on chromosome three, e, produces ebony body color. Trihybrid females are testcrossed to produce 4000 progeny, as follows: 1761 kidney, cardinal 1773 ebony 128 cardinal 97 kidney 89 ebony, cardinal 6 kidney, ebony,cardinal 8 wild type 138 kidney, ebony 1. Which gene is in the middle? 2.What is the distance between genes k and cd?arrow_forwardImagine the white flowers are recessive to purple flowers, and yellow seeds are recessive to green seeds. If a green-seeded, purple-flowered dihybrid is testcrossed, and half of the progeny have yellow seeds, what can you conclude about linkage between these loci? What do you need to know about the parents of the dihybrid in this case?arrow_forward
- An individual is heterozygous for a reciprocal translocation, with the following chromosomes: A • B C D E F A • B C V W X R ST • U D E F R ST • U V W X Q. Explain why the fertility of this individual is likely to be less than the fertility of an individual without a translocation.arrow_forwardAt the molecular level (with regard to loss-of-function alleles), explain why the ttvv homozygote has an ovate seed capsule.arrow_forwardConsider the genetic map below. (a) In a total of 1000 observed progeny, how many would be expected to be parental, non-recombinant? (b) If the total number of observed double-crossover recombinant progeny is 0, what is the interference? A-------20 cm-----B—5cm----Carrow_forward
- Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage LearningHuman Biology (MindTap Course List)BiologyISBN:9781305112100Author:Cecie Starr, Beverly McMillanPublisher:Cengage Learning