Porifera Biology Quiz
40 Questions
4 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What mechanism do Porifera use to maintain the flow of water through their bodies?

Porifera maintain water flow using a system of canals and aquifer systems.

How do the lifespans of sponges differ between temperate and tropical waters?

Sponges in temperate waters live for a few years, while those in tropical waters may live for over 200 years.

Describe the reproductive strategy of sponges.

Sponges reproduce both sexually and asexually, with most being hermaphrodites and engaging in cross-fertilization.

At what stage do some sponges begin sexual reproduction?

<p>Some sponges can start sexual reproduction as early as a few weeks old.</p> Signup and view all the answers

What role do choanocytes play in sponge reproduction?

<p>Choanocytes give rise to spermatozoa and can phagocytize sperm from other sponges.</p> Signup and view all the answers

Where does fertilization typically occur in sponges?

<p>Fertilization occurs in the mesohyl or in open water.</p> Signup and view all the answers

What is the significance of planktonic larvae in sponge reproduction?

<p>Planktonic larvae are released into the water for dispersal, allowing sponges to colonize new areas.</p> Signup and view all the answers

What evidence indicates that some sponges can grow very slowly?

<p>Some calcified sponges grow at a rate of only 0.2 mm per year, suggesting they can be thousands of years old.</p> Signup and view all the answers

What is the maximum duration that sponge larvae can live freely?

<p>Sponge larvae can live freely for a maximum of two days.</p> Signup and view all the answers

How do sponges primarily reproduce asexually?

<p>Sponges mainly reproduce asexually from fragments and some produce gemmules.</p> Signup and view all the answers

What evidence supports the colonial theory regarding the origin of animals?

<p>The similarity of coanocytes in sponges to those in coanoflagellates supports the colonial theory.</p> Signup and view all the answers

What are the main classes of Porifera based on skeleton composition?

<p>The main classes are Calcarea, Hexactinellida, and Demospongiae.</p> Signup and view all the answers

What distinguishes Calcarean sponges in terms of their skeleton?

<p>Calcarean sponges have skeletons made of calcite, a form of calcium carbonate.</p> Signup and view all the answers

What is the estimated total number of sponge species described?

<p>More than 10,800 species of sponges have been described, with an estimated total of around 15,000.</p> Signup and view all the answers

What is the primary characteristic of the mineral skeleton of glass sponges?

<p>It is composed of siliceous spicules known as hexactines, which have six sides and cross at right angles.</p> Signup and view all the answers

Which group is currently suggested to be the sister group of sponges?

<p>Ctenophora is suggested to be the sister group of sponges according to new evidence.</p> Signup and view all the answers

Approximately how long can glass sponges live?

<p>They can potentially live for up to 15,000 years.</p> Signup and view all the answers

How do some sponges attach to soft sediment?

<p>Some sponges attach to soft sediment through a root-like base.</p> Signup and view all the answers

Which class of sponges includes approximately 90% of sponge species?

<p>Demospongiae.</p> Signup and view all the answers

Identify the body complexity types found in the Porifera phylum.

<p>The body complexity types are Asconoid, Syconoid, and Leuconoid.</p> Signup and view all the answers

In which regions are sponges primarily distributed?

<p>Sponges are mainly found in tropical and subtropical areas but are present worldwide, including polar regions.</p> Signup and view all the answers

What distinguishes the Placozoa from other animals?

<p>Placozoa are considered the simplest multicellular organisms and do not have specialized organs or tissues.</p> Signup and view all the answers

What is the size range of Placozoa?

<p>Placozoa typically range from 0.5 to 1.00 mm in length and are about 25 µm thick.</p> Signup and view all the answers

How was Placozoa first misidentified upon discovery?

<p>At first, it was thought to be a larva of some other animal.</p> Signup and view all the answers

What are the two basic body forms of Cnidarians?

<p>The two basic body forms of Cnidarians are medusae (free swimming) and polyps (sessile).</p> Signup and view all the answers

Describe the function of tentacles in Cnidarians.

<p>The tentacles of Cnidarians bear cnidocytes, which are used for capturing prey and defense.</p> Signup and view all the answers

Explain the role of gonads in the reproduction of adult Cnidarians.

<p>The gonads in adult Cnidarians release ova and sperm into the water for sexual reproduction.</p> Signup and view all the answers

What is strobilation in the context of Cnidarian reproduction?

<p>Strobilation is the process by which a polyp splits horizontally to form juvenile medusae.</p> Signup and view all the answers

How do Cnidarians reproduce asexually?

<p>Cnidarians can reproduce asexually by budding or splitting, creating clones of the adult.</p> Signup and view all the answers

What is the primary difference in reproduction between Hydrozoan and Scyphozoan Cnidarians?

<p>Hydrozoan polyps primarily bud, while Scyphozoan polyps can both bud and split down the middle.</p> Signup and view all the answers

What happens to the larva in the life cycle of a jellyfish after it finds a suitable site?

<p>After finding a suitable site, the larva develops into a polyp.</p> Signup and view all the answers

Why are Cnidarians considered to have a simple nervous system?

<p>Cnidarians possess sensory organs and a decentralized nerve net, indicating a simple nervous system.</p> Signup and view all the answers

What are the seven classes of Cnidaria?

<p>Anthozoa, Cubozoa, Hydrozoa, Scyphozoa, Staurozoa, Myxozoa, and Polypodiozoa.</p> Signup and view all the answers

How many species are classified under the class Anthozoa?

<p>Approximately 6,100 species.</p> Signup and view all the answers

What is unique about the life cycle of Hydrozoa species?

<p>They alternate generations with asexual benthic polyps and sexual planktonic jellyfish phases.</p> Signup and view all the answers

What adaptation allows the Portuguese man-of-war to float?

<p>It uses gas-filled structures for buoyancy.</p> Signup and view all the answers

How many medusae do Cubozoa polyps typically produce?

<p>One medusa per polyp.</p> Signup and view all the answers

What is the potential danger of Cubozoa's tentacles?

<p>They contain potent venom capable of harming human beings.</p> Signup and view all the answers

What distinguishes the Hydrozoa class from other Cnidarians?

<p>Many Hydra species can exist as both polyp and medusa forms.</p> Signup and view all the answers

What is meant by the term 'monotypic' in relation to the Portuguese man-of-war?

<p>It means all individuals come from a single egg.</p> Signup and view all the answers

Study Notes

Porifera Biology

  • Porifera, commonly known as sponges, maintain a constant water flow to acquire food and oxygen while removing waste.
  • Lifespan varies: sponges in temperate waters can live a few years, whereas tropical and deep-ocean sponges may live over 200 years.
  • Growth rates can be exceedingly slow; some calcified sponges grow only 0.2 mm per year, with a 1 m sponge potentially being 5000 years old.

Porifera Reproduction

  • All sponges reproduce sexually, often hermaphroditic, enabling both male and female functions.
  • Gametes are produced in mesohyl, and fertilization typically occurs through cross-fertilization.
  • Sperm exits through the osculum; fertilization takes place in the mesohyl or open water, leading to planktonic larvae.

Role of Choanocytes

  • Choanocytes are critical in reproduction, giving rise to sperm and transforming into phorocytes to transfer sperm to eggs.
  • Larvae, after fertilization, are released via the aquifer system and have a brief free-swimming life (maximum of two days).

Asexual Reproduction in Porifera

  • Many sponges can reproduce asexually from fragments, with freshwater sponges producing gemmules for asexual propagation.

Phylogenetic Relationships

  • Historically viewed as the earliest animal lineage, sponges may be the sister group to all animals, largely based on choanocyte similarities to choanoflagellates.
  • New evidence suggests Ctenophora may form a sister group instead.

Porifera Diversity and Classification

  • Over 10,800 described species, potentially 15,000 species, categorized into five primary classes based on skeleton composition:
    • Calcarea: 400 species, skeletons made of calcite.
    • Hexactinellida: 690 species, glass sponges with silica skeletons estimated to live up to 15,000 years.
    • Demospongiae: 8,800 species, silica spicules or spongin fibers prevalent.

Distribution of Porifera

  • Sponges are predominantly marine but are found globally, thriving in both polar regions and tropical waters; a few species inhabit freshwater.

Placozoa Overview

  • Placozoa, the simplest known multicellular organisms, resemble amoebas and were first discovered in 1883.
  • Lacking specialized organs and tissues, they measure 0.5–1 mm long and have a radially symmetrical body.

Cnidaria Body Forms

  • Cnidarians have two primary body forms:
    • Medusae: free-swimming stage.
    • Polyp: sessile form; both stages possess a single orifice for digestion and respiration.
  • Common sensory organs and a simple nervous system exist in both forms.

Cnidaria Reproduction

  • Cnidarians often exhibit complex life cycles involving both polyp and medusa phases.
  • Asexual reproduction is widespread, allowing individuals to clone themselves.

Cnidaria Diversity and Classification

  • Approximately 16,000 species classified into seven classes, notable classes include:
    • Anthozoa: sessile, include anemones and corals.
    • Cubozoa: box jellies with potent venom.
    • Hydrozoa: hydras and Portuguese man-of-war forming floating colonies.
  • Each class demonstrates various life cycles, reproductive strategies, and ecological roles within aquatic environments.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Description

Test your knowledge on the biology of Porifera, including their structures and functions. This quiz covers aspects such as water flow, feeding, and lifespan variations in different environments. Dive into the fascinating world of sponges and see how much you know about these unique organisms.

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser