Videos
Prezygotic isolating mechanisms include all of the following except
a. hybrid sterility.
b. courtship rituals.
c. habitat separation.
d. seasonal reproduction
Introduction:
The reproductive isolation is achieved through the reproductive barriers which are the evolutionary mechanism or behaviors that prevent organism of a different species from breeding and leads to the prevention of exchange of genetic material. There are two types of reproductive barriers: Prezygotic barrier prevents the fertilization between species and postzygotic barrier prevents the maturation of hybrid zygote formed by the mating of two different species. Prezygotic barrier involves habitat, mechanical, gametic, behavioral, and temporal isolation. Postzygotic barriers involve reduced viability of the hybrid formed, reduced fertility of the hybrid and the breakdown of the hybrid that result in the sterile generations.
Answer to Problem 1U
Correct answer:
Hybrid sterility is the postzygotic barrier in which the produced hybrid formed due to the mating of two different species either does not develop properly (are sterile) or the adults do not survive for long. Therefore option a. is the correct answer.
Explanation of Solution
Reason for the correct statement:
The isolating mechanisms that prevent the formation of a zygote are known as the prezygotic isolation mechanism. It includes prevention of the fusion of gametes, ecological, behavioral, temporal, and mechanical isolation. Hybrid sterility is the postzygotic isolating mechanism in which the hybrid formed will be sterile and will not be able to reproduce.
Option a. is given as “hybrid sterility”.
As, “hybrid sterility is not a prezygotic isolating mechanism”, is the right answer.
Hence option a. is correct.
Reasons for the incorrect statements:
Option b. is given as “courtship rituals”.
The difference in courtship rituals is due to behavioral isolation which is a prezygotic isolating mechanism. So, it is a wrong answer.
Option c. is given as “habitat separation”.
Habitat separation is due to ecological isolation of species which is a prezygotic isolating mechanism. So, it is a wrong answer.
Option d. is given as “seasonal reproduction”.
Temporal isolation occurs when the species do not mate with each other due to their different reproduction seasons. It is also a prezygotic isolating mechanism. So, it is a wrong answer.
Hence options b., c., and d. are incorrect.
There are two types of reproductive isolating mechanisms: The prezygotic isolating mechanism which prevents the fertilization between species and the postzygotic isolating mechanism that prevents the maturation of hybrid zygote formed by the mating of two different species. These mechanisms are the barriers to facilitate successful reproduction and prevent the exchange of genetic material between species.
Want to see more full solutions like this?
Chapter 22 Solutions
Biology
- Problems with the biological species concept include the fact that a. many species reproduce asexually. b. postzygotic isolating mechanisms decrease hybrid viability. c. prezygotic isolating mechanisms are extremely rare. d. All of the choices are correct.arrow_forward5a) It is generally considered that blue or purplish colored flowers attract bees as pollinators. Red flowers often attract birds such as hummingbirds as pollinators. Is this an example of prezygotic or postzygotic isolating mechanisms? Why? 5b) The graphs in your textbook show that the parental species are partially isolated by living at somewhat different altitudes in the mountains. In nature, the two parental species are also strongly (but not completely) isolated by using different pollinators (bees vs. hummingbirds). Is the presence of altitudinal separation combined with different pollinators likely to give more reproductive isolation in nature compared to each isolating mechanism alone? Why? 5c) Do the figures showing the F2 generation of the flowers suggest that these traits of flower shape and flower color are polygenic or due to single gene loci? Give a reason for your answer. 5d) Looking at the other graphs for this example that are shown in your textbook, is there any…arrow_forward2) In some Drosophila species, conditions in the female reproductive tract do not allow the sperm of other species to survive long enough for fertilization to occur. What mechanism of reproductive isolation is in operation in this example? a.Temporal isolation. b.Mechanical isolation. c.Low hybrid viability. d.Gametic isolation.arrow_forward
- 1. What is speciation? 2. What is a “hybrid zone”? 3. What postzygotic barriers are often found in hybrid zones that result in a lack of species fusion? 4. What are the differences among the three possible outcomes for hybrids over time: reinforcement, fusion, and stability?arrow_forward1. The North American garter snake (7Thamnophis) has a number of sympatric populations that can be either terrestrial or aquatic. Terrestrial populations generally do not interbreed with aquatic populations, despite living in sympatry, because they are most likely separated by which pre-zygotic barrier? A. allopatric isolation by means of vicariance B. gamete isolation C. mechanical isolation D. habitat isolation E. allopatric isolation by means of dispersalarrow_forward7) A mule illustrates the effect of which type of isolation mechanism? a.Mechanical isolation. b.Temporal isolation. c.Hybrid inviability. d.Hybrid sterility.arrow_forward
- based on the image attached a) Explain how genetic drift caused egg hatching to decrease in the late 1980s and 1990. b) Why did hatching improve following translocations? c) What are the general effects of gene flow between populationsarrow_forward1. The North American garter snake (Thamnophis) has a number of sympatric populations that can be either terrestrial or aquatic. Terrestrial populations generally do not interbreed with aquatic populations, despite living in sympatry, because they are most likely separated by which pre-zygotic barrier? A. allopatric isolation by means of vicariance B. gamete isolation C. mechanical isolation D. habitat isolation E. allopatric isolation by means of dispersalarrow_forward1. The North American garter snake (7hamnophis) has a number of sympatric populations that can be either terrestrial or aquatic. Terrestrial populations generally do not interbreed with aquatic populations, despite living in sympatry, because they are most likely separated by which pre-zygotic barrier? A. allopatric isolation by means of vicariance B. gamete isolation C, mechanical isolation D. habitat isolation E. allopatric isolation by means of dispersal 2. Male dragonflies of one species are unable to grasp the abdomen of female dragonflies of a different species securely enough to mate, due to poor alignment of the four wings on each insect. This type of interference during mating attempts between different dragonfly species is: A. an example of a pre-zygotic barrier due to behavioral isolation B. an example of a pre-zygotic barrier due to gamete isolation C. an example of a pre-zygotic barrier due to mechanical isolation D. an example of a pre-zygotic barrier due to habitat…arrow_forward
- 10. The herbivorous Japanese ladybird beetle Henosepilachna yasutomii (which feeds on blue cohosh), and the sympatric beetle Henosepilachna nipponica (which feeds on thistles), do not ordinarily interbreed because they are reproductively isolated by which pre-zygotic barrier? A. mechanical isolation B. allopatric isolation by means of vicariance C. habitat isolation D. allopatric isolation by means of dispersal E. gamete isolationarrow_forwardADJUST Negative assortative mating means that organisms choose mates that are different from themselves. If negative assortive mating occurs in a population, what would expect to happen to genotype frequency over generations? O a) Frequency of the heterozygous genotype will increase. b) Frequency of the homozygous genotypes will decrease. O c) Frequency of the homozygous genotypes will increase. O d) Both A and B AUTO ||||||||| Cancel Revertarrow_forwardWhich of the following traits does not describe a r-selected species? A. rapid development B. low parental investment C. high reproductive rates D. short life spans E. late maturationarrow_forward
Human Anatomy & Physiology (11th Edition)BiologyISBN:9780134580999Author:Elaine N. Marieb, Katja N. HoehnPublisher:PEARSON
Biology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStax
Anatomy & PhysiologyBiologyISBN:9781259398629Author:McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa StouterPublisher:Mcgraw Hill Education,
Molecular Biology of the Cell (Sixth Edition)BiologyISBN:9780815344322Author:Bruce Alberts, Alexander D. Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter WalterPublisher:W. W. Norton & Company
Laboratory Manual For Human Anatomy & PhysiologyBiologyISBN:9781260159363Author:Martin, Terry R., Prentice-craver, CynthiaPublisher:McGraw-Hill Publishing Co.
Inquiry Into Life (16th Edition)BiologyISBN:9781260231700Author:Sylvia S. Mader, Michael WindelspechtPublisher:McGraw Hill Education