Bio - 7.1, 7.2, 7.3, 7.4, 7.5

Question 1

importance of food

Answer 1

• for growth
• source of energy
• for replacement of worn and damaged tissues

Question 2

balanced diet

Answer 2

• contains the right amount of carbohydrates, protein and fats in a single serving

Question 3

digestive system - process

Answer 3

mouth => esophagus => stomach => duodenum => ileum => colon => rectum => anus

Question 4

main stages of digestion

Answer 4

1. ingestion
2. digestion
3. absorption
4. assimilation
5. egestion

Question 5

ingestion

Answer 5

taking of substances into the body

Question 6

digestion

Answer 6

breakdown of food

Question 7

absorption

Answer 7

the movement of nutrient from the intestines into the blood

Question 8

assimilation

Answer 8

uptake and use of nutrients by cells

Question 9

egestion

Answer 9

the removal of undigested food from the body as feces

Question 10

physical digestion

Answer 10

• breakdown of food into smaller pieces
• no chemical change to food molecules
• increases surface area (quicker chemical digestion)

eg. chewing, bile

Question 11

chemical digestion

Answer 11

• breakdown of large insoluble molecules into small soluble molecules
• produces molecules absorbed

eg. enzymes

Question 12

mouth

Answer 12

• saliva = breaks down starch, moistens food
• teeth = cut food into smaller pieces

Question 13

esophagus

Answer 13

• moves food to the stomach

Question 14

stomach

Answer 14

• mixes food with enzymes and acids
• pH 1-2
• contains HCl acid to kill microorganisms

Question 15

duodenum

Answer 15

• first part of small intestine
• receives bile and enzymes
• neutralizes and absorption
• villi and microvilli

Question 16

ileum

Answer 16

• final part of the small intestine
• absorption of remaining nutrients
• villi and microvilli for absorption (longer than duodenum for maximised ROR)

Question 17

small intestine

Answer 17

• absorb nutrients and water into blood stream
• duodenum & ileum

Question 18

large intestine

Answer 18

• absorb water & recycle it

Question 19

rectum

Answer 19

• stores feces

Question 20

anus

Answer 20

• exit for feces

Question 21

liver

Answer 21

• filters blood
• produces bile to break down fats

Question 22

gall bladder

Answer 22

• stores bile

Question 23

pancreas

Answer 23

• make enzymes to break down foods

Question 24

crown - teeth

Answer 24

• enamel
• dentine

Question 25

root - teeth

Answer 25

• gum
• pulp cavity
• fibers
• jaw bone
• blood supply to the tooth

Question 26

enamel

Answer 26

• very hard covering
• contains calcium

Question 27

dentine

Answer 27

• layer containing living cells
• not as hard as enamel

Question 28

gums

Answer 28

• recedes with age

Question 29

pulp cavity

Answer 29

• contains blood vessels and nerves

Question 30

fibers

Answer 30

• help to hold tooth in the jaw bone

Question 31

tooth decay - process

Answer 31

particles of foods get trapped in cracks of teeth => bacteria feeds on the sugar form acids => dissolves hole in enamel and dentine => nerves affected => tooth pain => infection can spread quick => can form abscess at the root of the tooth

Question 32

dental decay

Answer 32

• bacteria + saliva = formed plaque
• plaque can harden and become tartar

Question 33

gum disease

Answer 33

• plaque can cause infections
• gums will swell and bleed
• bacteria may infect the root = loose teeth

Question 34

4 different teeth

Answer 34

1. incisors
2. canines
3. premolars
4. molars

Question 35

incisors

Answer 35

• cut food into smaller bits

Question 36

canine

Answer 36

• used to pierce and tear food

Question 37

premolar

Answer 37

• used to crush food

Question 38

molar

Answer 38

• used to grind and crush food

Question 39

alimentary canal

Answer 39

• long continuous tube where food physically travels
• starts from mouth ends at anus
• doesn’t include accessory organs (liver, pancreas, gallbladder)

Question 40

peristalsis movement - meaning

Answer 40

• wave-like muscle contraction
• occurs in the walls of the alimentary canal

Question 41

bile

Answer 41

• alkaline substance
• produced by liver
• stored in gallbladder
• emulsifies fats in small intestines

Question 42

emulsification

Answer 42

• process of breaking down large fat droplets into smaller droplets to increase surface area
• critical for fat digestion

Question 43

assimilation in LIVER

Answer 43

1. nutrients are absorbed through the villi
2. blood capillaries merges to form the Hepatic Portal Vein
3. transports glucose & amino acid to the liver
4. liver converts excess glucose into glycogen and stores it in the gall bladder

Question 44

villus - features (3)

Answer 44

• thin epithelium
• lacteal
• blood capillary

Question 45

thin epithelium

Answer 45

• one cell thick (increase diffusion)

Question 46

lacteal

Answer 46

• absorbs fatty acids and glycerol

Question 47

blood capillary

Answer 47

• absorb glucose and amino acids

Question 48

intestinal villi

Answer 48

• increase surface area for small intestine
• contain absorptive and goblet cells and lamina propria

Question 49

microvilli

Answer 49

• has a brush border
• further increase the surface area
• contains enzyme

Question 50

absorptive cells

Answer 50

• absorbing nutrients

Question 51

goblet cells

Answer 51

• produce mucus
• protect and lubricate the lining of the intestine

Question 52

lamina propria

Answer 52

• a layer beneath the epithelium
• contains blood vessels and lymphatic vessels
• transport absorb nutrient to the rest of the body