The Digestive System

Question 1

What is an autotroph?

Answer 1

Get food from environment - chemical or light e.g. photosynthesis

Question 2

What is a heterotroph?

Answer 2

Rely on plants/animals for nutrients as cannot get energy from environment

Question 3

What are the key functions of water?

Answer 3

50-70% of animal’s body weight
Allows chemical reactions to happen
Aids thermoregulatory system

Question 4

What are the key functions of fibre?

Answer 4

Regulate bowel function, aids removal of waste

Question 5

What are the key functions of carbohydrates?

Answer 5

Broken down into glucose = energy for cells, essential for organ function

Question 6

What are the key functions of lipids (fats)?

Answer 6

Storage of energy, insulation

Question 7

What are the key functions of protein?

Answer 7

Growth and maintenance of cells + tissues

Question 8

What is the key function of vitamins?

Answer 8

Promote chemical reactions

Question 9

What are the key functions of minerals?

Answer 9

Growth and maintenance of bones + teeth
Muscle contraction
Osmoregulation

Question 10

What are the 2 types of digestion?

Answer 10

Mechanical - large food pieces physically broken down

Chemical - food broken down by enzymes and acids (stomach)

Question 11

What are incisors (teeth) and what are they used for?

Answer 11

The front teeth, fine nibbling and cutting, delicate grooming

Question 12

What are canines (teeth) and what are they used for?

Answer 12

The largest teeth (like fangs), for holding prey and tearing meat

Question 13

What are premolars and molars (teeth) and what are they used for?

Answer 13

The middle and back teeth, for shearing and grinding food

Question 14

How are carnivore teeth adapted to their diet?

Answer 14

Meat diet
Canines to hold prey + rip meat
Carnassial teeth to shear meat
Lack the enzyme cellulase

Question 15

How are herbivore teeth adapted to their diet?

Answer 15

Plant diet
Incisors to cut plant material
Molars continuously grow as worn down by silica in plants
Grind food + mix with saliva

Question 16

Give 2 ways birds’ beaks are adapted to feed

Answer 16

Beaks adapted depending on diet
Shape of beak - e.g. hummingbird feed on nectar
Generally have a hooked or cured tip
Size of beak - e.g. pelicans feed on larger things

Question 17

What does the pancreas secrete and why?

Answer 17

Bicarbonate - regulate pH

Question 18

What is peristalsis?

Answer 18

Muscular contractions to push food along digestive tract

Question 19

Where is water absorbed?

Answer 19

Large intestine, through villi

Question 20

Explain hindgut fermenters

Answer 20

Animals who have a single-chambered stomach (monogastric) and a caecum

Eat mostly high fibre plants
fibre = hard to digest

Partially digested food goes to caecum and is fermented by microbes, breakdown cellulose

Question 21

Give 3 functions of the liver

Answer 21

1. Produces bile - emulsifies fats
2. Filters out toxins
3. Carbohydrate storage - converts glucose to glycogen

Question 22

What enzyme does saliva contain?

Answer 22

Amylase

Question 23

What enzymes are added in the stomach and what do they break down?

Answer 23

Protease - proteins
Lipase - fats/lipids

Question 24

Give 2 functions of the pancreas

Answer 24

1. Produce enzymes to aid digestion
2. Produce insulin and glucagon (hormones)

Question 25

Explain the process for detecting high blood glucose levels and subsequently reducing them

Answer 25

• Pancreas detects high blood glucose levels • Insulin secreted, glucagon secretion decreases • Insulin travels to liver + muscles • Body + muscles use excess glucose to make energy • Excess converted to glycogen by liver and muscle cells, stored • Blood sugar levels decrease

Question 26

What is the difference between type 1 and type 2 diabetes?

Answer 26

Type 1 - lack of insulin Type 2 - insulin resistance (linked to obesity)

Question 27

Explain the 4 chambers in the ruminant digestive system

Answer 27

Rumen - largest, storage + fermentation, cellulase break down plant material Reticulum - small food particles move on to omasum, large particles go back Omasum - absorb water + salt Abomasum - true stomach

Question 28

Explain avian digestion

Answer 28

Birds do not have teeth - use tongue to move food to back of mouth Passes to proventriculus - digestive enzymes + HCl added Then moves to ventriculus (gizzard) - mechanical digestion, water re-absorbed, food fermented Waste excreted out of cloaca as one mixed substance

Question 29

Give 3 causes of vomiting and diarrhoea

Answer 29

Unsuitable type or amount of food / foreign bodies / contaminated food / stress / pathogens

Question 30

What does chunky or granular vomit mean?

Answer 30

Food related signs Chunky - undigested food, eaten too quickly or ran around after eating Granular - partly digested

Question 31

What does liquid (foamy, slimy or clear) vomit mean?

Answer 31

Disease

Question 32

What is ruminant bloat?

Answer 32

When gas builds up in rumen