Heterochrony is
a. the alteration of the spatial pattern of gene expression.
b. a change in the relative position of a body part.
c. a change in the relative timing of developmental events.
d. a change in a signaling pathway.
Introduction:
Changes in the development, contribute towards the evolution. The species which are closely related differ from each other because of the genetic changes. These genetic changes lead to differences in their developmental pattern, which result in producing different phenotype. The types of these developmental changes include homeosis and heterochrony.
Answer to Problem 1U
Correct answer:
The alterations in the timing of developmental events due to genetic changes are called heterochrony. Therefore, option c. is correct.
Explanation of Solution
Reason for the correct statement:
When the transcription factors are modified during evolution, they bring changes in the gene function. These changes in genes bring alterations in the timing of developmental events. Such modifications are known as heterochrony.
Option c. is given as "a change in the relative timing of developmental events".
As, “in heterochronic mutations, alterations in the timing of developmental events take place as a result of evolutionary changes in the genes”, is the right answer.
Hence, option c. is correct.
Reasons for the incorrect statements:
Option a. is given as “the alteration of the spatial pattern of gene expression”.
The alterations in the spatial pattern of gene expression, is a type of homeosis. So, it is a wrong answer.
Option b. is given as “a change in the relative position of a body part.”
Change in the relative position of a body part is a type of homeotic mutation, which does not produce a phenotype which is viable. So, it is a wrong answer.
Option d. is given as “a change in the signaling pathway”.
Change in the signaling pathway, results in the appearance of a homeotic phenotype. So, it is a wrong answer.
Hence, options a, b and d are incorrect.
A change in the relative timing of developmental events is known as heterochrony.
Want to see more full solutions like this?
Chapter 25 Solutions
Biology with Connect Access Card
- How is a protein destined for the Endoplasmic Reticulum (ER), imported into the ER? Be concise.arrow_forwardFind out about the organisations and the movements aimed at the conservation of our natural resources. Eg Chipko movement and Greenpeace. Make a project report on such an organisation.arrow_forwardWhat are biofertilizers and mention the significancearrow_forward
- PCBs and River Otters: Otters in Washington State’s Green-Duwamish River have high levels of polychlorinated biphenyls (PCBs) in their livers. PCBs can bind to the estrogen receptors in animals and disrupt the endocrine system of these otters. The PCBs seem to increase the estrogen to androgen ratio, skewing the ratio toward too much estrogen. How would increased estrogen affect the river otter population? Based on your reading of the materials in this unit, what factors can affect fertility in humans? Explain how each of the factors affecting human fertility that you described can disrupt the human endocrine system to affect reproduction.arrow_forwardOther than oil and alcohol, are there other liquids you could compare to water (that are liquid at room temperature)? How is water unique compared to these other liquids? What follow-up experiment would you like to do, and how would you relate it to your life?arrow_forwardSelection of Traits What adaptations do scavengers have for locating and feeding on prey? What adaptations do predators have for capturing and consuming prey?arrow_forward
- Competition Between Species What natural processes limit populations from growing too large? What are some resources organisms can compete over in their natural habitat?arrow_forwardSpecies Interactions Explain how predators, prey and scavengers interact. Explain whether predators and scavengers are necessary or beneficial for an ecosystem.arrow_forwardmagine that you are conducting research on fruit type and seed dispersal. You submitted a paper to a peer-reviewed journal that addresses the factors that impact fruit type and seed dispersal mechanisms in plants of Central America. The editor of the journal communicates that your paper may be published if you make ‘minor revisions’ to the document. Describe two characteristics that you would expect in seeds that are dispersed by the wind. Contrast this with what you would expect for seeds that are gathered, buried or eaten by animals, and explain why they are different. (Editor’s note: Providing this information in your discussion will help readers to consider the significance of the research).arrow_forward
- Biology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage Learning
- Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage LearningConcepts of BiologyBiologyISBN:9781938168116Author:Samantha Fowler, Rebecca Roush, James WisePublisher:OpenStax College