Annelida Flashcards

Questions and Answers

Give a few examples of animals found within the taxon Annelida.

Earthworms, leeches, clamworms

How many species are found within the phylum Annelida?

15,000

During which time period did the phylum Annelida originate?

Pre Cambrian

What is the major contribution of the phylum Annelida in relation to global temperatures?

Recycling decomposed carbon Signup and view all the answers

Briefly characterize the phylum Annelida.

Segmented bodies called metameres Signup and view all the answers

What are the 'new' evolutionary features of the phylum Annelida?

Metanephridia, coelom, segmented body Signup and view all the answers

What is metamerism, and what is its importance?

Segmentation of the body Signup and view all the answers

What are setae, and why are they important?

Hairlike bristles made out of chitin Signup and view all the answers

Give a brief overview of the classification within the phylum Annelida.

Class Polychaeta: Marine Annelids, Class Oligochaeta: Marine, freshwater, and terrestrial annelids like earthworms, Class Hirudinea: Freshwater and terrestrial leeches Signup and view all the answers

Characterize the class Oligochaeta.

More than 3000 species, live on land and in water, don't have super pronounced setae Signup and view all the answers

What is the ecological importance of earthworms?

They aerate soil and decompose organic matter Signup and view all the answers

Explain how earthworms move.

Using peristaltic motion with circular and longitudinal muscles Signup and view all the answers

What is a typhlosole?

Dorsally folded portion of the intestine used to increase surface area Signup and view all the answers

Give a brief overview of the digestive system in an earthworm.

Includes calciferous gland and typhlosole Signup and view all the answers

What is the importance of the circular and longitudinal muscles in earthworms?

They help with locomotion Signup and view all the answers

Briefly describe the circulatory system in an earthworm.

Blood goes through dorsal vessels to aortic arches and then to the ventral vessel Signup and view all the answers

How does an earthworm exchange gases with its surrounding environment?

Through diffusion Signup and view all the answers

How do earthworms reproduce?

They are monoecious and exchange sperm to fertilize eggs in a cocoon Signup and view all the answers

Give a brief overview of the anatomy of the reproductive system in earthworms.

Monoecious or hermaphrodites, have a clitellum that secretes mucus Signup and view all the answers

Briefly describe the nervous system of an earthworm.

They have a ganglia and a ventral nerve cord Signup and view all the answers

Study Notes

Examples of Animals in Annelida

Earthworms belong to Class Oligochaetes.
Leeches are classified under Class Hirudinea.
Clamworms are part of Class Polychaetes.

Species and Origin

Approximately 15,000 species of annelids exist.
Annelida originated during the Pre-Cambrian period.

Contribution to Global Temperatures

Annelids play a crucial role in recycling decomposed carbon.
They help regulate greenhouse gases, which can affect global temperatures and climate stability.

Characteristics of Annelida

Bodies are segmented into metameres.
Other than leeches, members possess setae, chitinous bristles aiding in movement and gas exchange.

New Evolutionary Features

Introduction of metanephridia for excretion.
Presence of a coelom (body cavity).
Segmented body structure allows for increased complexity.

Importance of Metamerism

Segmentation leads to more organized and complex bodily systems.
Enhances movement capabilities through localized control.

Setae Explanation

Setae are hairlike bristles made of chitin.
Vital for locomotion and facilitating gas exchange.

Classification Overview

Class Polychaeta includes marine annelids.
Class Oligochaeta comprises terrestrial and freshwater annelids like earthworms.
Class Hirudinea consists of leeches found in freshwater and terrestrial environments.

Class Oligochaeta Characteristics

Contains over 3,000 species.
Found in terrestrial and aquatic habitats.
Generally lack pronounced setae.

Ecological Importance of Earthworms

Aerate soil to improve air and water access for plant roots.
Decompose organic matter, enriching soil nutrient content.

Earthworm Movement

Utilizes peristaltic motion for locomotion.
Anterior circular muscles contract to elongate the body, followed by longitudinal muscles contracting to propel forward.

Digestion in Earthworms

Equipped with calciferous glands for calcium and pH regulation.
The typhlosole increases intestinal surface area for enhanced nutrient absorption.

Importance of Muscles

Circular and longitudinal muscles aid in effective movement throughout each body segment.

Circulatory System Overview

Distinction between coelomic fluid and blood systems.
Blood circulates through dorsal vessels and aortic arches, which pump it into the ventral vessel for body-wide distribution.

Gas Exchange

Earthworms exchange gases primarily through diffusion across their moist skin surfaces.

Reproduction Process

Earthworms are monoecious, possessing both male and female reproductive organs.
They engage in copulation, exchange sperm, and create a cocoon for fertilized eggs.

Reproductive Anatomy

Hermaphroditic structure, characterized by a clitellum that secretes mucus for copulation.

Nervous System Structure

Comprised of a ganglia and a ventral nerve cord, coordinating movement and responses.

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Description

Test your knowledge of the phylum Annelida with these flashcards. Explore various examples of annelid species, their origins, and unique contributions. Perfect for students or anyone interested in biology.