An Anatomy of the Earthworm Trivia Quiz

Answer: False

Earthworms have two openings: the mouth and the anus. Only through the mouth can the earthworm take in soil, and only through the anus can the waste products exit. In this sense, it is ideal that the earthworm propels itself forward to ingest the soil and to defecate it out the back.

Answer: segmented worm

Segmented worms have "segments" separated by small furrows. These types of worms are often known as annelids, which also includes leaches. Each segment has muscles that allow the worm to propel itself forward. Earthworms are generally born with the same amount of segments that they will live their entire lives with.

Answer: chitin

Chitin is biologically similar to keratin; however, keratin is found in mammals, which makes up hair and nails. Epithelial cells are a certain type of skin cells. Collagen is a material that is plentiful throughout the human body. It helps make up our skin, ligaments, tendons, and even our bones.

Answer: brain

According to the textbook "Animals Without Backbones", the earthworm's brain seems to have inhibitory effects, so removing it causes the worm to move continuously. In another scientific study, when the earthworm's brain was removed, it continued to move forward into a wall, without realizing it was being blocked, like a normal earthworm would.

However, removing the brain would not generally kill an earthworm!

Answer: A - red; tube-like and near the center

The thin, red tubes were indeed the blood vessels which typically encircle the digestive tract. The large, brown cavernous tube was just that: the digestive tract/intestine. The black tubes that ring the outside of the worm are ganglia, which are part of the nervous system. Finally, the green, coiled string is the metanephridium, which is part of the excretory system and serves as the worm's kidney, removing metabolic waste.

Answer: clitellum

Earthworm reproduction typically involves two separate organisms, which inseminate each other. The clitellum releases mucus in two separate instances: as the worms copulate to keep themselves attached to each other (though the setae also help) and also once more to create a mucus ring. The worm then slowly backs out of the ring and injects its eggs and the opposite worm's sperm into the mucus material. Then a cocoon forms, from which baby worms will hatch.

The incorrect options are all parts of an animal cell.

Answer: gizzard

In earthworms, the gizzard utilizes small stones that the worm has consumed along with the soil to break down its food. The pharynx helps push the food down the tract; while passing through the esophagus, the food passes by calciferous glands that help remove excess calcium from the worm's body; the crop stores the food for a bit before passing to the gizzard for breaking down the food.

After that, it is off to the intestine to soak up the nutrients.

Answer: castings

Castings (casts) are actually very helpful for the environment; worms eat decaying matter and convert it into a form that plants can metabolize. It is common to use worm castings as a natural way to help fertilize gardens. While Darwin was studying worm anatomy and biology, he felt it necessary to draw several examples of these worm castings in great detail in his famous work "The Formation of Vegetable Mould through the Action of Worms". Anything in the name of science, I suppose!

Answer: It has photoreceptors.

The photoreceptors that earthworms possess allow them to sense light (though not "see" it in the traditional sense). These sensors are positioned mostly on the prostomium, which is the very first segment of an earthworm that overhangs its mouth like a lip.

The sensors tell earthworms that they are in the daylight and need to get to safety; one of the earthworm's greatest dangers is drying out and the sun can be vicious to the little creatures.

Answer: Yes

Earthworms have the ability to regenerate body tissues. While it is much easier to regenerate the posterior sections, some earthworms have been known to regenerate their anterior (frontward) sections as well. Worms certainly don't make becoming a meal easy, and if you have ever gone fishing, you might know that pulling worms from their soil can be quite troublesome!