Nutrition

Question 1

Define the term parasite and give an example (2)

Answer 1

• live in or one a host and obtain nutrient whilst harming the host
• tapeworm/ticks/leeches/headlice

Question 2

Describe the terms autotroph and give an example (2)

Answer 2

• use simple inorganic molecules to synthesise organic compouns
• plant/algae

Question 3

Describe the term saprophyte and give an example (2)

Answer 3

• secrete enzymes onto foood outside the body and absorb soluble products
• bacteria/fungi

Question 4

Describe two features of an epithelium cell and explain why it is impotant for cell to function effieintly (4)

Answer 4

• microvilli
• increase surrface area for diffusion
• mitochondria
• synthesis of ATP for active transport

Question 5

What is the function of goblet cells (1)

Answer 5

• secretes mucus

Question 6

Where is the main regions in human gut where digestion and absorption occurs (2)

Answer 6

• digestion - mouth ,stomach,small intestine
• absorption - small intestine , large intestine

Question 7

Explain why the human digestive system is divided into several regions (1)

Answer 7

• different parts carry out different functions
• provide differnt conditions for enzymes
• difference food groups digested in different areas

Question 8

Suggest why it is a benefit for tapeworm to live in small intestine (1)

Answer 8

• region has hgih concentration of products of digestion
• tapeworm can absorb nutrients
• nourishment from digested food

Question 9

How are tapeworms adapted overcome persitalsis and digestive enzymes (2)

Answer 9

• peristalsis - hooks and suckers attatch to gut wall
• digesive enzymes - thick cuticle/secretes muscus/secretes enzyme inhibitors

Question 10

Suggest why tapeworms produce large number of eggs (1)

Answer 10

increases chance of surrvival / infeting a new host / many eggs will not survive

Question 11

Which is the most acidic region of the alimetnary canal (1)

Answer 11

• stomach

Question 12

In which two areas are proteins,carbohydrates and lipids digested together (1)

Answer 12

• duodenum
• ileum

Question 13

Where does the process of protein digestion begin (1)

Answer 13

• stomach

Question 14

Where is the main site of lipase production (1)

Answer 14

• pancreas

Question 15

The setion of the alimentary canal where most absorption of digested products occur (1)

Answer 15

• ileum

Question 16

The section of the alimentary canal whose main function is to absorb water (1)

Answer 16

• large intestine /colon

Question 17

Explain how the jaw and teeth in herbivores are adapted for their nutrition (3)

Answer 17

• large molars for grinding
• diastma to manipular food
• well developed incisors for tearing vegetation
• very small / no canines
• loos articulation jaw moves in horizontal plame
• open roots to allow continous growth is molars

Question 18

Explain how the gut of a herbivore is adapted for digestion (2)

Answer 18

• four chembered stomach
• contain cellulose digesting bacteria
• long gut allow extra time for digestion of cellulose
• cud is regurgitated for further chewing

Question 19

Describe how the tapeworm is adapted to obtain its nutrients (3)

Answer 19

• attaches to gut wall by hooks and suckers
• large surface area to volume ration
• digested in host gut absorbed into tapeworm
• short diffusion pathway

Question 20

Explain how hooks andd suckers help the adult tapeworm to survive (2)

Answer 20

• atttach to the gut wall
• worm does not get movedalong via persitalsis /prevent it being egested

Question 21

State why the adult tape worm does not need a digestive system and explain how the worm body enables it to feed without moth of gut (3)

Answer 21

• lives surrounded by food that has been digested down by human digestvie system
• long large surface area to absorb digested food
• thin short sdiffusion distance

Question 22

Describe how the tapeworm’s reproductive strategy helps to ensure its survival (2)

Answer 22

• large numbers of eggs
• eggs can resist adverse conditions

Question 23

Give an account of sequence of events take place during digestion and absorption of meal containing carbohydrate and protein (10)

Answer 23

• in buccal cavity
• teeth mechanically break down food
• salive from salivary glands
• saliva containss mucus to lubricate
• amylar substrate is starch product is maltose
• stomach adapted for protein digestion
• produces hydrochloric acid
• peptidase is protein products are polypeptides
• small intestine adapted to complete protein digestion
• protease produced in small intestine
• pancreas produce lipase and amylase
• endo peptidase and exo peptidase
• absorption takes place in ileum
• villi increase surface area
• glucose are absorbed by diffusion and active transport

Question 24

Explain two features are important in functioning of the villus (4)

Answer 24

• microvilli
• increase surface area for greater absorption of digested products
• large capillary network - transport glucose maintain diffusion gradient
• lacteal - absrob lipids
• thin epithelium - short diffusion parthway

Question 25

Explain two functions of the secretion of mucus via goblet cells for process of digestion (2)

Answer 25

* reduced frictions for passae of food * prevents effect of acid on gut wall

Question 26

Layers of smooth muscle are found in wall of small intestine explain the role of these muscle layers in process of digestion (3)

Answer 26

* peristalsis * circular and longitudinal muscles contract * forces food along

Question 27

Amino acids are absorbed and transported to live what are the fate of excess amino acids (2)

Answer 27

* deamination * reamainder to carbohydrate

Question 28

State three feature of gut parasites adaption to parisitic way of life (3)

Answer 28

* hooks and suckers for attathment to gut * large surface area to volume ration * thin * covering resistant to digestive enzymes * produce large number of eggs

Question 29

Give reasons from dentition of a carnivorous diet (2)

Answer 29

* large carnines for tearing / killing prey * molars for slicing meat * small inciors for gripping flesh * carnassials for crushing * vertical movements of jaws

Question 30

Describe similar mode of nutrition between carnivores and parasites (1)

Answer 30

obtains food from other organisms / heterotrophs

Question 31

describe how parasitic nutrition is different to carnivores (2)

Answer 31

* parasites requires digested food by host whereas carnivores have digestive system * parasites absorb food externally whereas carnivores is interal absorption

Question 32

With reference to structure of starch and cellulose explain why alpha amylae is unable to digest cellulose even through starch and cellulose are polymers of glucose (3)

Answer 32

* reference active site of alpha amylase and ock and key theory * complementary shape only to starch not cellulose * starch contain alpha glucose but cellulose contain beta glucose * regerence to coloiling in starch and straight chains in cellulose

Question 33

Why do endopeptidase act before exopeptidase (2)

Answer 33

* endopeptidase hydrolyse peptide bonds in middle of polypeptide chain creating smaller polypeptides * many peptides increase number of terminal peptide bonds for exopeptidases to hydrolyse

Question 34

Use examples of sheep and tapeworm and describe and explain the structural adaptations they possess for particular mode of nutrition (10)

Answer 34

* sheep