6 Animal Nutrition

Question 1

State what is meant by the term balanced diet for humans

Question 2

List the principal sources of, and describe the dietary importance of carbohydrates, fats, proteins, vitamins C & D, mineral salts calcium and iron, fibre and water

Question 3

Factors that affect human dietary needs

Answer 3

age, gender, activity; also pregnancy and breast-feeding

Question 4

Effects of malnutrition

Answer 4

starvation, constipation, coronary heart disease, obesity and scurvy

Question 5

Explain the causes and effects of vitamin D and iron deficiencies

Question 6

Explain the causes and effects of protein-energy malnutrition

Answer 6

Kwashiorkor and Marasmus

Question 7

Define ingestion

Answer 7

the taking in of substances into the body through the mouth

Question 8

Define digestion

Answer 8

the breakdown of large, insoluble food molecules into small, water-soluble molecules using mechanical and chemical processes

Question 9

Define mechanical digestion

Answer 9

the breakdown of food into smaller pieces without chemical change to the food molecules

Question 10

Define chemical digestion

Answer 10

the breakdown of large, insoluble molecules into small, soluble molecules

Question 11

Define absorption

Answer 11

movement of digested food molecules through the wall of the intestine into the blood

Question 12

Define assimilation

Answer 12

the movement of digested food molecules into the cells of the body where they are used, becoming part of the cells

Question 13

Define egestion

Answer 13

passing out of food that has not been digested, as faeces, through the anus

Question 14

Identify the main regions of the alimentary canal and associated organs

Answer 14

mouth, salivary glands, oesophagus, stomach, small intestine, pancreas, liver, gall bladder, large intestine and anus

Question 15

Describe the functions of the regions of the alimentary canal in relation to ingestion, digestion, absorption, assimilation and
egestion of food

Question 16

Types of human teeth

Answer 16

Incisors, canines, premolars, molars

Question 17

Describe the structure of human teeth

Answer 17

Include: enamel, dentine, pulp, nerves and cement, the gums

Question 18

Describe the functions of the types of human teeth in mechanical digestion of food

Question 19

Describe the proper care of teeth

Answer 19

Reference diet and regular brushing

Question 20

State the causes of dental decay

Answer 20

a coating of bacteria and food on teeth, the bacteria respiring sugars in the food, producing acid which dissolves the enamel and dentine

Question 21

Chemical digestion in the alimentary canal is significant in …

Answer 21

producing small, soluble molecules that can be absorbed

Question 22

Functions of the enzymes amylase, proteases and lipase

Answer 22

Amylase - breaks down starch to simpler sugars
Proteases - break down protein to amino acids
Lipase - breaks down fats to fatty acids and glycerol

Question 23

State where, in the alimentary canal, amylase, protease and lipase are secreted

Question 24

State the functions of the hydrochloric acid in gastric juice

Answer 24

Kills bacteria in food and gives an acid pH for enzymes

Question 25

Explain the functions of the hydrochloric acid in gastric juice, limited to the low pH

Answer 25

denatures enzymes in harmful microorgansims in food, gives the optimum pH for protease activity

Question 26

The role of bile

Answer 26

emulsifying fats to increase the surface area for the chemical digestion of fat to fatty acids and glycerol by lipase, neutralising the acidic mixture of food and gastric juices entering the duodenum from the stomach, to provide a suitable pH for enzyme action

Question 27

The role of villi

Answer 27

increase the internal surface area in the small intestine

Question 28

Describe the structure of a villus

Question 29

Describe the roles of capillaries and lacteals in villi