2.4 - adaptations for nutrition

Question 1

food must be digested because the molecules are…? 2

Answer 1

1. insoluble and too big to cross membrane and be absorbed into the blood
2. polymers must be converted to monomers - can be rebuilt to molecules

Question 2

digestion and absorption occur in the…?

Answer 2

gut - long hollow muscular tube that only allows one direction for its contents

Question 3

what are the 4 functions of the gut?

Answer 3

1. ingestion-taking food in
2. digestion-break down of large insoluble molecules
3. absorption - passage of molecules and ions through gut wall into blood
4. egestion- elimination of waste e.g. food that can’t be digested - cellulose

Question 4

look at diagram on page

Answer 4

222

Question 5

what is function of the oesophagus?

Answer 5

carriage of food to stomach

Question 6

what is function of the duodenum?

Answer 6

digestion of carbohydrates, fats and proteins

Question 7

what is function of the stomach?

Answer 7

digestion of protein

Question 8

what is function of the ileum?

Answer 8

absorption of digested food

Question 9

what is function of the colon?

Answer 9

absorption of water

Question 10

what is function of the rectum?

Answer 10

storage of faeces

Question 11

what is function of the anus?

Answer 11

digestion

Question 12

going from outer layer to inner what is the order of layers in the gut wall?

Answer 12

serosa, longitudinal muscles, circular muscle, submucosa, muscosa

Question 13

what are carbohydrating digestion enzymes called

Answer 13

carbohydrase

Question 14

how are proteins digested?

Answer 14

digested into polypeptides then dipeptides and the amino acids - protease

Question 15

what enzyme digests fats to fatty acids and glycerol?

Answer 15

lipase

Question 16

where is bile made? stored?

Answer 16

liver, gall bladder

Question 17

how does bile provide a suitable pH for enzymes in small intestine?

Answer 17

bile is alkaline and neutralises acid in food coming from stomach

Question 18

what is the part ileum in the small intestine adapted for good absorption

Answer 18

6 metres long have microvilli which produce large SA

Question 19

what 3 things do salvia contain?

Answer 19

1. amylas
2. bicarnoate ions
3. mucus

Question 20

how do reptiles ingest their food?

Answer 20

ingest it whole

Question 21

what do mammals have a palate separating nasal and mouth cavities?

Answer 21

allows them to eat food whilst breathing

Question 22

what is a carnivores diet mainly composed of?

Answer 22

protein - small intestine short so easy to digest

Question 23

why do herbivores a long intestine?

Answer 23

mostly eat plants and plants aren’t digested easily - has to be long to allow time for digestion and absorption of nutrients

Question 24

what 4 types of teeth do humans have?

Answer 24

incisors, canines, premolars and molars

Question 25

where are incisors and canines located?

Answer 25

lower jaw

Question 26

describe the movement of lower jaw when animals chews.

Answer 26

circular motion

Question 27

why is a herbivores skull not need strong muscles attached to jaw?

Answer 27

food is unlikely to try and escape

Question 28

what do incisors do?

Answer 28

grip and tear muscle off bone

Question 29

how are canine teeth adapted for tearing muscle and killing?

Answer 29

biggest teeth, sharp and pointed for piercing

Question 30

which teeth are responsible for cutting and crushing?

Answer 30

premolars and molars

Question 31

what do carnassials do?

Answer 31

shear muscle off bone

Question 32

describe the action of lower jaw when a dog chews?

Answer 32

vertical - not side to side like herbivores

Question 33

what is a ruminant

Answer 33

a cud-chewing herbivore that has mutualistic microbes in its rumen

Question 34

what is ruminants food consist of?

Answer 34

cellulose

Question 35

how is cellulose broken down in a ruminant?

Answer 35

rely on mutualistic bacteria living in gut to secrete enzymes needed to digest cellulose

Question 36

give 3 examples of mutualistic microbes?

Answer 36

1. bacteria
2. fungi
3. protoctista

Question 37

why is study of parasites economically important?

Answer 37

cause disease in humans, crops and domesticated animals

Question 38

is pork tape worm a endoparasite or ectoparasite

Answer 38

endoparasite

Question 39

how long can pork tape worms grow

Answer 39

10 metres

Question 40

what is the scolex and what is it res in the tapeworm?

Answer 40

anterior end - made of muscle which attaches itself to duodenum wall

Question 41

what are the sections of the tapeworm called?

Answer 41

proglottids

Question 42

what are the primary and secondary costs of the tapeworm?

Answer 42

primary - human

secondary - pig

Question 43

how does each host become contaminated?

Answer 43

pig- when food is contaminated with human faeces

humans - eating undercooked food - infected pork

Question 44

what 3 problems does he tapeworm face in the human gut?

Answer 44

1. surrounded by digestive juices
2. exposed to hosts immune system
3. if host dies so does parasite

Question 45

name 2 ways the tapeworm survives the hostile environment of the host?

Answer 45

1. develop only organs needed for survival

2. produce many eggs high chance of transmission to second host

Question 46

what 2 structural modifications does the tapeworm have to allow it yo live as parasite?

Answer 46

1. thick body covering - protection from host immune response
2. eggs haves resistant shells and survival until eaten by secondary host

Question 47

what happens if person eats eggs directly from the meat?

Answer 47

embryos from cysts in various organs even brain