Adaptations For Nutrition

Question 1

What region does hydrolysis of protein begin?

Answer 1

The stomach.

Question 2

Where is the enzyme amylase produced?

Answer 2

The pancreas.

Question 3

What is the function of the lacteal?

Answer 3

Absorbs fatty acids and glycerol.

Question 4

What is the function of capillaries in the villi?

Answer 4

Absorb glucose an amino acids.

Question 5

Apart from it’s length, state te other ways in which the surface of the small intestine is increased.

Answer 5

Folded.
Numerous villi.
Microvilli.

Question 6

Explain why the digestion of proteins is more efficient if they are exposed to endopeptidases before being acted upon by exopeptidases.

Answer 6

Endopeptidases cuts in the middle of the chain/produces several smaller chains.
Producing many ends for exopeptidases to act upon.

Question 7

How does the arrangement of fibres differ in the two muscle layers in a gut wall?

Answer 7

One layer has fibres arranged longitudinally, one has circular fibres.

Question 8

What term is used for the process by which the muscle layers push food along the gut?

Answer 8

Peristalsis.

Question 9

Name two structures found in the sub-mucosa a and give their functions in nutrition.

Answer 9

Blood vessels-transport products of digestion.
Lymph vessels-transport lipids.
Nerves-co-ordinate muscular contractions.
Glands-secrete enzymes or mucus.

Question 10

Describe one adaptation of its dentition to its diet for a herbivore and carnivore.

Answer 10

Herbivore-incisors in lower jaw only, with horny pad for cutting/interlocking molars for grinding/gap/enamel ridges continue to grow.
Carnivore-sharp incisors to grip and tear flesh from bone/large canines for seizing or killing prey/tearing flesh/carnassials for shearing flesh/crushing bone.

Question 11

Explain why the gut of a carnivore is much shorter than the gut if a herbivore.

Answer 11

Protein is easier to digest compared with cellulose.

Question 12

Describe how the stomach of a herbivore like a sheep is adapted to its diet.

Answer 12

The cud is mixed with cellulose digesting bacteria.
Cud can be regurgitated.
Allows water to be reabsorbed. 
Presence of bacteria in rumen.
Some absorption eg of fatty acids.

Question 13

Suggest why the carnivore like a lion has a large stomach, even tho the remainder of its gut is reduced.

Answer 13

Carnivores catch prey periodically and can use their stomach to store their catch until the next time they make a kill/diet is mainly protein and it is the stomach where protein is digested.

Question 14

Define the term parasite.

Answer 14

A parasite is an organism which lives on or in another organism (the host) obtaining nourishment at the expense of the host, causing harm to the host.

Question 15

Name the secondary host of a tapeworm.

Answer 15

A pig.

Question 16

Describe how the parasite is transmitted from a human to it’s secondary host.

Answer 16

The pig becomes infected if it feeds in places contaminated by human faeces.

Question 17

Explain how humans may become infected with the tapeworm.

Answer 17

Eating undercooked infected pork.

Question 18

State one adaptation of the tapeworm which ensures it stays in place in the gut of the host.

Answer 18

Suckers/hooks.

Question 19

Explain why the tapeworm is not destroyed by the secretions of the human host.

Answer 19

A thick cuticle which produces inhibitory substances to prevent digestion by the host’s enzymes.

Question 20

The tapeworm has a very high rate of reproduction. Explain how this is advantageous to the parasite.

Answer 20

To overcome the problem of transfer to another host/to increase the chance of some of the offspring reaching another host.

Question 21

Where is bile produced?

Answer 21

The liver.