Adaptations for nutrition Flashcards
1
Q
Describe the term parasite and give an example (2)
A
- parasites live in/ on a host and obtain nourishment whilst harming the host
- tapeworm / ticks/ / leeches / fleas / headlice / roundworm / malaria parasite
2
Q
Describe the term autotroph and give an example (2)
A
- autotroph use simple inorganic molecule to synthesis organic compounds
- plants / algae / bacteria
3
Q
Describe the term Saprobionts and give an example (2)
A
- secrete enzymes onto food outside the body / feed by extracellular digestion and absorb the soluble products
- bacteria / fungi
4
Q
Describe two features of epithelium why each important for the cell to function efficiently (4)
A
- mircovilli
- increase surface diffusion
- mitochondria
- synthesis of ATP for active transport
5
Q
What is the name for the cell inside the epithelium and its function (2)
A
- goblet cell
- secrets mucus
6
Q
Where does digestion and absorption take place (2)
A
- digestion - mouth , stomach , small intetine
- abssorption - large intesine , small intestine
7
Q
Explain why the human digestive sytem is divided into several regions (1)
A
- different parts carry out different functions
- provide different conditions for enzymes
- different food groups digested in different areas
8
Q
What is meant by the term parasite (2)
A
- lives in or on another organism
- obtains nutrients from host causing harm to the host
9
Q
Suggest why it is of benefit to the tapeowrm to live in this region of the digetive system (1)
A
high concentration of products of digestion so it can absorb the nutritents
10
Q
Describe how tapeworms are adapted to overcome persitalsis in the human digestive system (1)
A
hooks / suckers to attach to gut wall
11
Q
Describe how tapeworms are adapted to overcome digestive enzymes in the human digestive system (1)
A
thick cuticle / secretes mucus / secretes enzyme inhibitors coating the waxy cuticle
12
Q
Suggest why tapeworms produce a large number of eggs (1)
A
increases chance of species survival / infecting a new host / many eggs will not survive
13
Q
Which is the most acidic region of the alimentary canal (1)
A
stomach and bile duct
14
Q
In which two area are proteins , carbonhydrates and lipids digested together (1)
A
- ileum
- duodenum
15
Q
Where does the process fo protein digestion begin (1)
A
stomach
16
Q
Where is the main site of lipase production (1)
A
pancreas
17
Q
The secretion of the alimentary canal where most abssorption of digested products occurs (1)
A
duodenum
18
Q
The secretion of the alimentary canal whose main functions is to absorb water (1)
A
large intestine / colon
19
Q
Explain how the jaw and teeth of herbivores are adapted for the mode of nutrition they use (3)
A
- large ridged molar for gringing
- diastema to assist with chewing and manipulating food into cud
- sharp incissors for biting / cutting
- loose articulation / jaws move in a circular plant
- very small / no canines
- open roots for continuous growth of molars
20
Q
Explain how the gut of herbivores are adapted for digestion (2)
A
- four chambered stomach
- contains cellulose digesting bacter have cellulase
- long gut to allow extra tiem for digestion of cellulose
- cud is regurgitated for further chewing
21
Q
How are tapeworms adapted to obtain its nutrients (3)
A
- attatches to the gut wall by hooks and suckers
- large surface area to volume ration
- digested products in host gut absorbed into tapeworm
- short diffusion pathway
22
Q
Identify two structures of tapeworm allow them to survive in the gut of a human and explain the structures (3)
A
- hooks abd scukers
- attatch the worm to the wall of the gut
- the worm does not get move along resisting persitalsis
- prevents it getting egested
23
Q
State why the adult tape worm does not need a digestive system and explain how the hape of the worms body enables it to feed without a mouth or gut (3)
A
- it lives surrounded by food digested by hot
- very long gives large surgace area to absorb digested food
- flat and thin sshort distance for diffusion
24
Q
Explain how the tapeworms reproductive strategy helps to ensure it’s survival (2)
A
- it lays a large number of eggs
- eggs can resist adverse conditions
- both male and female reproductive organs
25
Give an account of the sequence of events that takes place during difestion and absorption of a meal containing carbohydrate and protein (10)
* in buccal cavitty /mouth
* teeth and tongue mechanically break down food to produce a large surface area
* saliva added from salivary glands
* saliva contain mucus to lubricate
* amylase substrate is starch product is matlose / disaccharides
* stomach adapted for protein digestion / proteins partially digested in the stomach
* produces hydrochloric acid in tomach
* peptidase / pepsis substrate is protein product are polypeptides
* small intestine is adapted to completes protein / carbohydrate digestion
* names enzymes produced from small intestine
* two names enzymes produced by pancreas
* description of endo - exo peptidases
* absorption takes place in ileum / small intestine
* villi / microvilli increase surface area
* glucose products are absorbed by diffusion and active transport
26
Describe two featuress that are important in functioning of the villus (4)
* mircovilli - increase large surface area increased catalytic surface area for digestion
* dense capillary network - transport glucose and amino acids maintain a stepp concentration gradient
* prescence of lactal / lymph vessel - absorb lipids fats / fatty acids
* thin epithelium - short diffusion pathway
27
Name the substance secreted by goblet cells (2)
mucus
28
Explain two functions of the secretion of goblet cell in process of digestion (2)
* reduces friction for the passage of food
* preventing the effect of enzymes and digestion on gut wall
29
Layers of smooth muscle are found in the wall of the small intestine explain the role of these muscle layers in the process of digestion (3)
* persitalsis
* circular and longitudinal muscles wave of muscle contraction
* forces food along mixes food for efficient absorption
30
Amino acids are transpored to liver describe the fate of the excess amino acids absorbed (2)
* deamination / amino group removed
* amino groups to urea
* remainder to carbohydrate
31
Describe how carnivores are adapted for eating (3)
* large pointed canines for tearing and killing prey
* molar / premolars for cutting meat
* small incisors gripping flesh
* carnissials teeth for crushing
* vertical movements of jaws
32
How is parasitic nutrition similar to a carnivores mode of nutrition (1)
obtains food from another organism
33
Explain how parasitic nutrition is different to carnvivore mode of nutrition (2)
* parasite do not need a digestive system wehreas B has a digestive system
* A absorbs food externally and B is internal absorption
34
With reference to the structure of starch and cellulose molecules explain why alpha amylase is unable to digest celluloe even through starch adn cellulose are both polymers of glucose (3)
* referecne to lock and key hypothesis and enzyme substrate complexes
* complementary shape only to starch
* starch contains alpha glucose but cellulose contains beta glucose
* coiling in starch / straight chains in cellulose / cross linking in cellulose/ alternatfe glucose molecules rotated by 180 degress whereas molecules not rotated in starch
35
How can rabbits digest cellulose without their cells being able to produce the necessary enzyme (1)
enzyme cellulase veing produced by bacteria
36
State where an ezyme with low Ph would be found (1)
stomach
37
State and enzyme with high ph would be found (1)
ileum / small intestine
38
Explain why the endopeptidase have to act on a protein before exopeptidase (2)
* endopeptidase hydrolyse peptide bonds in the middle of the polypeptide chain
* because many peptides increase the number of terminal peptide bonds for exopeptidases to hydrolyse
39
Using examples of a shepp and a tapeworm describe and explain the structural adaptations they possess for theirr particular mode of nutrition (10)
Sheep
* it is a herbivore
* has a high diet in cellulose
* the jaw moves in a horizontal plane allowing to grind plant material
* teeth have open unrestricted roots to allow teeth to grow throughout their lives
* it has incisors on the lower jaw which cut grass against horny pad
* they have large ridged molars to grind plant materials
* it has a relativley lond gut as cellulose is relativley hard to digest
* they are ruminants possess a four chamber stomach
* rumen contains mutualistic bacteria which can digest cellulose
* possess a diastema whcih enables to chew of cud and manipulate food with tongue
Pork tapeworm
* is a parasite
* nutriontally dependent on hot
* possess hooks and suckers
* allow is attatch to gut wall preventing it being dislodged during peristalsis
* absorbs small soluble nutrients poduced byhosts digestion across it body surface
* long thin and flattened to provide a large surface area for absorption
40
Explain why the enzyme iss secreted in an inactive form (1)
active form would digest cells
41
The optimum pH of trypsin is in the range of 7.8 0 8.7 Explain how this pH is maintained in the duodenum (3)
* alkaline secretion / bile
* from brunner's gland / pancreas / liver cells / gall bladder
* neutralise acid from stomach / increase pH / acts as a buffer
42
Define the term saprotrophic (1)
Enzymes are secreted outside the body / extracellular digestion and the products of digestion are absorbed
43
Describe how the tapeworm is adapted to resist peistalsis in human intestine (1)
scolex / hooks and suckers attatch to gut wall
44
Explain why the tapeworm does not need a mouth or alimentary canal (2)
* nutrients absorbed through its body surface not need a mouth
* food is pre digested
45
Suggest why the tapeworm relies on anaerobic respiration for its metabolism (1)
* oxygen levels are too low for aerobic respiration in the intestine
* has a low metabolic rate and not require aerobic respiration does not move that much
46
Describe how the small intestine enables the tapeworm to survive in the environment within the host (4)
* thick cuticle protects the worm from the effects of enzymes
* lime secretion neutralises acid
* mitotriches increase surface area for absorption of digested food
* glands secrete mucus to protect the worm from digested enzymes
* musclees allow tapeworm to increase contact with digested food
47
Body walls of tapeworms have been observed to contain transmembrane proteinss involved in active transport mechanisms suggest how these mechanisms aid the survival of the parasite inside th host (2)
* enable worm to absorb ions / amino acids
* against the concentration gradient
48
Domestic dogs are able to digest starch unlike wolves Explain how wolves and dogs are both adapted to feed mainly on a carnivore diet Describe the process of starch digestion and suggest the advantage to domesticated dogs of being able to digest starch (9)
* wolves and dogs have carnivore dentition
* sharp incisors and lond pointed canines, carnassial teeth for shearing through bond , ligaments and tendons
* relativley short gut adapted fro protein digestion
* salivary amylase hydrolyses starch to maltose
* optimum pH maintained by mineral salts / buffers in saliva
* starch digestion resumes in duodenum with pancreatic amylase
* maltose digested by glucose by maltase in small intestine
* Domestic dogs fed on human food waste containing large amounts of starch
* some dogs better digesting starch than others
* Dogs that oculd digest starch well more olikely to survive and breed can live on human waster
* wolves cannot digest starch as the wolves cannot produce amylase
