Questions and Answers
What makes an organism an invertebrate?
No backbone
Why are earthworms classified as annelids?
They have rings or segments that make their bodies
External segments of annelids are called?
Metameres
Where is the mouth located in an earthworm?
Signup and view all the answers
Where is the anus located in an earthworm?
Signup and view all the answers
What are septa and where are they located?
Signup and view all the answers
Are earthworms segmented internally?
Signup and view all the answers
Name the internal cross walls that separate the inside of an earthworm.
Signup and view all the answers
What is the swollen band around the worm and what is its purpose?
Signup and view all the answers
What is the 'lip' called and what is its function?
Signup and view all the answers
What are setae and where are they located?
Signup and view all the answers
What is the function of setae?
Signup and view all the answers
At what segment do the reproductive structures start?
Signup and view all the answers
What are seminal receptacles?
Signup and view all the answers
What are seminal vesicles?
Signup and view all the answers
What are ovaries?
Signup and view all the answers
What are testes?
Signup and view all the answers
Describe earthworm mating.
Signup and view all the answers
Why are earthworms hermaphrodites?
Signup and view all the answers
What are the hearts called?
Signup and view all the answers
How many hearts does an earthworm have?
Signup and view all the answers
What are the two major blood vessels in earthworms?
Signup and view all the answers
Is circulation in earthworms open or closed? Why?
Signup and view all the answers
Name the parts of an earthworm's digestive tract in order beginning with the mouth.
Signup and view all the answers
What is the mouth in the context of an earthworm?
Signup and view all the answers
What does the pharynx do?
Signup and view all the answers
What is the function of the esophagus?
Signup and view all the answers
What is the purpose of the crop?
Signup and view all the answers
What is the function of the gizzard?
Signup and view all the answers
What does the intestine do?
Signup and view all the answers
What is the anus in the context of an earthworm?
Signup and view all the answers
What are ganglia?
Signup and view all the answers
Earthworms respond to ___________ from their environment.
Signup and view all the answers
What is the job of the excretory system?
Signup and view all the answers
What are nephridia?
Signup and view all the answers
Where are nephridia found in an earthworm?
Signup and view all the answers
What gas do earthworms need to live?
Signup and view all the answers
How do earthworms obtain their oxygen?
Signup and view all the answers
Do earthworms fertilize their own eggs?
Signup and view all the answers
What are the three main parts of the earthworm's nervous system?
Signup and view all the answers
What is the purpose of a cocoon in earthworms?
Signup and view all the answers
What is the difference between seminal receptacles and seminal vesicles in earthworms?
Signup and view all the answers
Study Notes
Earthworms Overview
- Earthworms are invertebrates, meaning they lack a backbone.
- Classified as annelids due to their segmented body structure featuring rings called metameres.
Body Structure
- Anterior end is where the mouth is located; the posterior end houses the anus.
- Septa are the internal dividing walls found between segments of the worm.
- Earthworms exhibit internal segmentation, reinforced by the presence of septa.
- Setae are bristles located on the underside, present between segments, aiding in movement.
Reproductive Features
- The clitellum is a swollen band vital for reproduction, indicating readiness to mate.
- The prostomium, a liplike structure, assists in soil excavation.
- Reproductive structures emerge from segment 9, including seminal receptacles (segments 9 and 10) for storing sperm, and seminal vesicles (segments 9-12) where testes are located.
- Ovaries in segment 13 produce eggs.
- Earthworms are hermaphrodites, producing both eggs and sperm; fertilization happens externally.
Circulatory System
- Earthworms have five aortic arches, functioning as hearts.
- Circulatory system is closed, meaning blood is contained within vessels.
Digestive System
- The digestive tract includes: mouth → pharynx → esophagus → crop (temporary food storage) → gizzard (breaks down food) → intestine (digestion and absorption) → rectum → anus (excretes waste).
- Anus facilitates the passage of undigested material.
Nervous System
- Composed of a ventral nerve cord, brain, and ganglia (masses of nerve cells).
- Earthworms respond to environmental stimuli via nerve impulses.
Excretory System
- Eliminates metabolic wastes through nephridia, tiny white structures located on the dorsal body wall, performing excretory functions.
- Ensures homeostasis within the organism.
Respiration
- Earthworms require oxygen for survival, obtained through skin respiration where gases are exchanged with the environment.
Miscellaneous
- Earthworms do not fertilize their own eggs; they require a partner for reproduction.
- A cocoon serves as a protective capsule for female eggs, created by the clitellum during reproduction.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Explore the fascinating world of earthworms, invertebrate annelids known for their unique segmented bodies. This quiz covers their body structure, reproductive features, and key anatomical components like the clitellum and setae. Test your knowledge on these important soil organisms!