Parasites can anchor themselves to the walls of the digestive tract at various p

ID: 80040 • Letter: P

Question

Parasites can anchor themselves to the walls of the digestive tract at various points. Consider the digestive functions of parasites that attach themselves to the PARASITE REX walls of the various parts of the digestive system. INSIDE THE BIZARRE WORLD OF NATURES MOST DANGEROUS CREATURES Attachment Own Digestion Host Digestion Carl Zimmer oint Mouth Stomach Small intestine SUPERB... A NON-STOP DELIGHT NEW SCIENTIST For each attachment point, indicate which types of macromolecules the See question associated parasite would have to be able to digest on it's own versus those which with Figure 41.13 (p904) it must rely on the host for digestion.

Explanation / Answer

Answer:

Position

Own digestion

Host digestion

Mouth

Has to depend its own digestion for carbohydrates, protein and fat

Some carbohydrate might be absorbed in the mouth from host

Stomach

Amino acid

Carbohydrate, Fat

Small intestine

Do not have to depend much on its own digestion

Amino acid, Carbohydrate and fats will be available in the host intestine which can be easily absorbed

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Tapeworms are endoparasites which have numerous adaptations to enhance parasitic nutrition. Tapeworms live in the small intestine of humans, providing an ideal location to access a readily available, rich source of pre-digested nutrients. Since nutrients in the small intestine are plentiful and pre-digested by the host, tapeworms do not require a gut and instead have adaptations to maximise nutrient absorption. Tapeworms have a tegument which allows nutrients to be absorbed directly from the host small intestine by diffusion. They also have anatomical adaptations in the form of a scolex with hookers and suckers to allow the parasite to attach to the host small intestine wall, preventing the tapeworm from being egested following peristalsis. Tapeworms have a flattened body with microtriches to maximise the surface area available for nutrient absorption and they additionally have various transporter molecules.