Adaptions for Nutrition

Question 1

Herbivore teeth adaptions

Answer 1

High cellulose diet

Teeth adaptions:

• Horny pad on the upper jaw to provide hard surface for incisors/canines to cut against
• Diastema (gap with no teeth) to allow animals long flexible tongues to manipulate plant material within the mouth
• Loose articulation of the lower jaw, allowing it to move in a horizontal plane to produce a circular motion for grinding

Question 2

Carnivore teeth adaptions

Answer 2

High lipid and protein diet which has a high energy content compared to herbivore diets

Teeth adaptions:

-Carnassial teeth are very large, sharp specialised molars. Used to shear muscle off bone, also crack and crush bones and cut meat into small enough sizes to swallow

Question 3

Carnivore gut adaptions

Answer 3

• Their digestive system is adapted for eating meat
• Meat is mostly protein which is easily digested by protease enzymes
• Therefore they have a relatively short gut in relation to their body length

Question 4

Herbivore gut adaptions

Answer 4

• The digestive system of herbivores is adapted for eating plants
• They have a long gut in relation to their body as plant material isn’t not readily digested

Question 5

Ruminants

Answer 5

A ruminant is a cud chewing herbivore that has mutualistic microbes in its rumen (part of stomach)

E.g. Cow:

• Ruminant food is mostly cellulose from cell walls as they largely eat grass
• Animals do not make the enzyme cellulase
• They rely on mutualistic microbes living in their gut to secrete cellulase instead
• These microbes live in a chamber called the rumen

Question 6

Parasites - Head louse and Tapeworms

Answer 6

Organism that obtains its nutrition at the expense of the host. The host is always harmed.

HEAD LOUSE:
-Ectoparasite which feeds by sucking blood from the scalp of the host

• Has claws to hold onto hairs and lays eggs which are glued onto the base of hairs
• Transfer between hosts is by direct contact

PORK TAPEWORM:
-Endoparasite found in the gut of humans as primary hosts

• Feeds by absorbing pre-digested nutrients directly through its cuticle
• Larval form develops in pigs as secondary host after pigs ingest eggs from human faeces
• Infection of humans occurs when a person eats undercooked pork which contains live larval forms
• To increase chances of infecting a secondary host large numbers of eggs are produced which pass out in the faeces

Tapeworms are adapted to living in the hostile gut by having:

• Thick cuticle covering the body to protect from host immune system
• Anti-enzyme secretions which prevent it from being digested
• Hooks on the scolex (head) to attach to duodenum wall