Ch. 28 - Green Algae and Land Plants

Freeman - Biological Science 8th Edition

Freeman8th EditionBiological ScienceISBN: 9780138276263Not the one you use?Change textbook

Freeman 8th Edition

Ch. 28 - Green Algae and Land Plants

Problem 13

Chapter 28, Problem 13

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Moss sperm are motile and capable of swimming short distances to fertilize an egg. However, it was unknown until recently how sperm make their way from male to female gametophytes that may be separated by a distance of several centimeters or more.
Beyond the results presented here, what other evidence would be useful when drawing conclusions about the role of springtails in moss reproduction?

Verified step by step guidance

Consider the ecological interactions between mosses and springtails. Investigate whether springtails are commonly found in environments where mosses grow, and if their presence correlates with successful moss reproduction.

Examine the physical characteristics of springtails that might facilitate the transport of moss sperm. For example, study their movement patterns and body structures to determine if they can carry or transfer sperm effectively.

Conduct experiments to observe the behavior of springtails in the presence of moss sperm. Determine if springtails are attracted to moss sperm or if they exhibit behaviors that suggest they are involved in sperm transport.

Analyze the genetic material of mosses in areas with and without springtails to see if there is a difference in genetic diversity or reproductive success, which could indicate the role of springtails in facilitating cross-fertilization.

Investigate the chemical signals or cues that might be involved in attracting springtails to moss sperm. Identify any pheromones or other chemical attractants that could play a role in this interaction.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Moss Reproduction

Mosses reproduce sexually through the production of gametes: sperm and eggs. The sperm are motile and swim to reach the egg for fertilization. This process typically occurs in moist environments, which facilitate sperm movement, highlighting the importance of water in moss reproduction.

Role of Springtails

Springtails are small, soil-dwelling arthropods that may play a role in moss reproduction by aiding in the transport of sperm between gametophytes. Understanding their behavior and interactions with mosses can provide insights into their potential role as facilitators in the reproductive process, especially over distances where direct sperm swimming is insufficient.

Evidence in Biological Research

In biological research, evidence is crucial for drawing conclusions about ecological interactions. Useful evidence could include observational studies of springtail behavior, experiments demonstrating sperm transport by springtails, and genetic analyses showing successful fertilization facilitated by these organisms. Such evidence helps clarify the mechanisms of moss reproduction involving springtails.

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Evidence of Natural Selection

Related Practice

Textbook Question

You have been hired as a field assistant for a researcher interested in the evolution of flower characteristics in orchids. Design an experiment to determine whether color, size, shape, scent, or amount of nectar is the most important factor in attracting pollinators to a particular species. Assume that you can change any flower's color with a dye and that you can remove petals or nectar stores, add particular scents, add nectar by injection, or switch parts among species by cutting and gluing.

Textbook Question

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Researchers hypothesized that small animals called springtails (a type of arthropod) facilitate sperm transfer in mosses. To test this hypothesis, the researchers grew patches of male and female mosses at varying distances from each other and in the presence or absence of springtails. They later checked to see how many sporophytes were found in each female patch (as an indicator that fertilization had occurred). Their results are shown in the graph here (** means P<0.01, * means P>0.05. What conclusions can be drawn about the role of the springtails during the reproductive cycle of the mosses?

Textbook Question

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What structure do moss sperm use for motility, and how does that reflect the evolution of land plants from green algae?

Textbook Question

Moss sperm are motile and capable of swimming short distances to fertilize an egg. However, it was unknown until recently how sperm make their way from male to female gametophytes that may be separated by a distance of several centimeters or more. A friend in your biology study group claims that eggs in mosses are fertilized by spores. What is wrong with that statement?

Textbook Question

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Besides springtails, are there other ways moss sperm may be transferred from male to female gametophytes?

Textbook Question

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Animals are responsible for pollinating many flowering plants. Did animal-mediated fertilization originate with flowering plants, or was this mode of sperm dispersal likely in place before the origin of flowering plants? Explain.