Questions:

Please answer in point form.

1. When and how did earthworms arrive in North America? (1 mark)

Travelers from Europe would bring plants from their country with earthworms around the roots of

plants in the soil.

2. Why is it difficult to find fossil evidence for Earthworms? (1 mark)

Earthworm fossils are soft-bodied and have no bones.

3. What is the primary form of fossil evidence for Earthworms and how old do they suggest that the

annelid phylum dates back to? (1 mark)

Tunnels in rocks that may be burrows that were formed when the worms wriggled through the sand.

Fossil annelids date back 500 million years ago.

4. What is the complete scientific classification (Kingdom all the way down to Species) for the

earthworm being considered in this virtual dissection? (1 mark)

Kingdom, Phylm Annelid, class Oligochaeti, Order Opisthopora, Lambricihae family, Eisenia genus, fetida

species.

5. What are the scientific terms for head and tail/rear end? (1 mark)

The scientific term for head is anterior and the scientific term for tail is posterior.

6. Please define segment versus setae. (1 mark)

Segment is a corduroy or a lot of rings connected together. Setae refers to small hairs or bristles on

segments. Setae have four pairs of bristly "hairs" on each ring or segment.

7. Referring to your unit notes, what is the function of the clitellum? (1 mark)

secrete a mucous cocoon for the egg

8. Where specifically is the prostomium found and what is its function? (1 mark)

very tip of the anterior and is used to gather sensory information about their environment

9. How many "hearts" does an earthworm have, and referring to your unit notes, what is the scientific

name for an earthworm's heart? (1 mark)

An earthworm has five hearts and their scientific names are pseudohearts.

10. Please explain how circular and long (longitudinal) muscles work together to coordinate

earthworm movement. (3 marks)

Circular muscles tighten up and the body becomes thinner and longer, squeezing the front end forward,

while the long muscles squeeze together and help move the rear end towards the front end.

11. Referring to your unit notes, please explain the function of the crop and gizzard. (2 marks)

Food is stored in crop, and in gizzards, muscles break down food.

12. How does an earthworm exchange oxygen and carbon dioxide with the atmosphere and what key

condition must exist for it to do so? (2 marks)

Earthworms take in oxygen through the moist skin, from where it goes into the bloodstreams.

13. Is Herman likely a male or female? Please explain. Referring to your unit notes, what is the

scientific term for animals that have reproductive capabilities such as Herman? (2 marks) Rhetorical

question: Why do you think they named the worm Herman?

Because male organs are located in the head and female organs are located within the clitellum,

Herman can be both male and female. The name “Herman” comes from the word “hermaphrodites”,

which refers to both male and female organs.

14. Please explain briefly how earthworms reproduce. (3 marks)

Two worms join together with heads pointing in opposite directions. The clitellum secretes a mucus

layer to protect sperm as it transfers and each earthworm injects sperm into the mucus which moves

into a pouch like seminal receptacle of each worm. After a few days each worm secretes a tube of

mucus and chitin which picks up the worms eggs and stored sperm. The sperm and egg are then

expelled through a slime tube and fertilization takes place.

15. Please explain why earthworms as referred to as one of nature’s top "soil scientists". (2 marks)

They act as decomposers, maintain the fertility of soil, release nutrients into the soil, loosen and aerate

the soil

16. How many earthworms may be found in an acre of land? (1 mark)

More than a million earthworms

17. What is the largest earthworm ever recorded? (1 mark)

Found in South Africa and measured 22 feet