Bio C7

Question 1

1.What is a balanced diet?

Answer 1

A balanced diet is a diet that contains the correct proportions of nutrients that the body needs to function correctly (e.g. carbohydrates, lipids, proteins)

Question 2

2. Why do pregnant/breastfeeding women need a larger caloric intake?

Answer 2

They need more energy to support the development of the child. （The diet needs to be balanced as well to provide the correct nutrients）

Question 3

3. What is constipation caused by?

Answer 3

A lack of dietary fibre

Question 4

4. What is scurvy caused by?

Answer 4

A lack of vitamin C

Question 5

5. Give 2 sources of Vitamin C in the diet

Answer 5

Fruit, Vegetables

Question 6

6. What are the causes and effects of vitamin D deficiency?

Answer 6

-Not enough sunlight
- Not enough oily fish, egg yolks or milk
Vitamin D deficiency can cause rickets in children which leads to weak bones which can cause deformities

Question 7

7. What is ingestion?

Answer 7

The intake of substances into the body through the mouth

Question 8

8. What is mechanical digestion?

Answer 8

The process of breaking down food without altering it chemically (also called physical digestion)

Question 9

9. What is chemical digestion?

Answer 9

Breaking insoluble large molecules into smaller soluble ones

Question 10

10. What is absorption?

Answer 10

The process where ions and broken down food molecules move into the blood through the wall of the intestine

Question 11

11. What is assimilation?

Answer 11

The movement of digested food molecules into the cells of the body where they are used

Question 12

13. What is egestion?

Answer 12

The removal of undigested food as waste from the anus

Question 13

14. Identify the structures of the digestive system labelled in the diagram

Answer 13

Question 14

15. Describe the passage of food through the alimentary canal

Answer 14

Mouth → oesophagus → stomach →small intestine → large intestine → rectum

Question 15

16. What role does the pancreas play in digestion?

Answer 15

The pancreas secretes digestive enzymes into the small intestine

Question 16

17. Name the 2 parts of the small intestine

Answer 16

Duodenum and ileum

Question 17

18. How is the ileum adapted for absorption?

Answer 17

The ileum is lined with villi and microvilli which provide a large surface area for absorption

Question 18

19. Name four types of teeth

Answer 18

Incisors, Canines, Premolars, Molars

Question 19

20. What is the purpose of chemical digestion? Which enzymes involve in chemical digestion?

Answer 19

Breaking larger insoluble molecules into smaller soluble molecules that can be absorbed.
Amylase, maltase, Protease (pepsin, trypsin), lipase

Question 20

21. Give 2 places in the alimentary canal that amylase is secreted

Answer 20

• The pancreas
• The salivary glands in the mouth

Question 21

22. Give 2 places in the alimentary canal that protease is secreted

Answer 21

• The pancreas
• The stomach

Question 22

23. Where in the alimentary canal is lipase secreted?

Answer 22

The pancreas

Question 23

24. What are the functions of the hydrochloric acid in gastric juice?

Answer 23

• Killing bacteria
• Gives the appropriate (acidic) pH for enzymes to work

Question 24

25. What does bile do?

Answer 24

-Bile neutralises the stomach acid and provides alkaline conditions for the digestive enzymes in the small intestine
- Bile also emulsifies fats which increases their surface area for chemical digestion

Question 25

26. Describe the structure of a villus

Answer 25

• Central lacteal used for transporting fatty acids and glycerol in the lymph fluid
• Lots of capillaries to absorb nutrients into the blood
• Thin wall to minimise the diffusion distance

Question 26

27. State 2 parts of the alimentary canal where water is absorbed

Answer 26

• The small intestine (most water absorbed here)
• The colon