☀️ • Lesson 1.3 : Plant and Human Nutrition (Bio)

Question 1

Describe Photosynthesis

Answer 1

Photosynthesis Is the process by which plants synthesize carbohydrates from raw materials using energy from light.

Question 2

State the word equation for photosynthesis

Answer 2

Carbon dioxide + water → glucose + oxygen
(In the presence of light and chlorophyll)

Question 3

What is chlorophyll and its function?

Answer 3

Chlorophyll is a green pigment that is found in chloroplasts, that transfers energy from light into energy in chemicals for the synthesis of carbohydrates.

Question 4

What is the balanced symbol equation for photosynthesis?

Answer 4

6CO2 + 6H2O → C6H12O6 + 6O2

Question 5

What is starch used for in plants?

Answer 5

Starch is used as an energy store

Question 6

What is cellulose used for in plants?

Answer 6

Cellulose is used to build cell walls

Question 7

What does glucose do for plants?

Answer 7

Glucose is used for respiration to provide energy

Question 8

What is sucrose used for in plants?

Answer 8

Sucrose is used for transport in the phloem

Question 9

Why do plants make nectar?

Answer 9

Nectar attracts insects for pollination

Question 10

Why are nitrate ions important for plants?

Answer 10

Nitrate ions help plants make amino acids.

Question 11

Why are magnesium ions important for plants?

Answer 11

Magnesium ions help plants make chlorophyll.

Question 12

How do light, CO₂, and temperature affect photosynthesis?

Answer 12

More light, CO₂, and heat = faster photosynthesis.

Question 13

What happens to gas exchange in aquatic plants in light and dark?

Answer 13

In light: Take in CO₂, release O₂.
In dark: Take in O₂, release CO₂.

Question 14

Why do leaves have a large surface area and are thin?

Answer 14

Large surface area = more light for photosynthesis.
Thin shape = shorter distance for gases to move in and out.

Question 15

What structures in the leaf help with gas exchange?

Answer 15

Stomata: Openings for CO₂ in and O₂ out.
Guard cells: Control the opening/closing of stomata.

Question 16

What structures in the leaf help with photosynthesis?

Answer 16

Chloroplasts: Contain chlorophyll for photosynthesis.
Palisade mesophyll: Main site for photosynthesis.

Question 17

What structures in the leaf help with water and nutrient transport?

Answer 17

Vascular bundles: Contain xylem and phloem for transport.

Xylem: Carries water.
Phloem: Transports nutrients.

Question 18

What is a balanced diet?

Answer 18

A diet that includes all essential nutrients in the right amounts for health and energy.

Question 19

What causes scurvy and rickets?

Answer 19

Scurvy: Lack of vitamin C — causes weak gums & skin.
Rickets: Lack of vitamin D — causes weak bones.

Question 20

What are the main sources and importance of carbohydrates?

Answer 20

Sources: Bread, rice, pasta, potatoes.
Importance: Provides energy for the body.

Question 21

What are the main sources and importance of fats and oils?

Answer 21

Sources: Butter, oils, nuts, avocados.
Importance: Energy storage, insulation, and protection for organs.

Question 22

What are the main sources and importance of proteins?

Answer 22

Sources: Meat, fish, eggs, beans.
Importance: Needed for growth and repair of tissues.

Question 23

What are the main sources and importance of vitamins C and D?

Answer 23

Vitamin C: Found in citrus fruits (needed for healthy skin and gums).
Vitamin D: Found in fish, eggs, sunlight (needed for strong bones).

Question 24

What are the main sources and importance of calcium and iron?

Answer 24

Calcium: Found in milk, cheese (needed for strong bones & teeth).
Iron: Found in red meat, spinach (needed for red blood cells).

Question 25

What are the main sources and importance of fibre (roughage)?

Answer 25

Sources: Whole grains, fruits, vegetables. Importance: Helps with digestion and prevents constipation.

Question 26

Why is water important in the diet?

Answer 26

Water helps with digestion, transport of nutrients, and temperature control.

Question 27

What is the correct order of the alimentary canal?

Answer 27

Mouth → Oesophagus → Stomach → Small intestine (duodenum → ileum) → Large intestine (colon → rectum → anus)

Question 28

What is the function of the salivary glands, and where are they found?

Answer 28

Function: Produce saliva with enzymes (ex. amylase) to start digestion. Location: In the mouth, near the jaw and cheeks.

Question 29

What is the function of the pancreas, and where is it found?

Answer 29

Function: Produces enzymes for digestion and insulin for blood sugar control. Location: Below the stomach, near the small intestine.

Question 30

What is the function of the liver, and where is it found?

Answer 30

Function: Produces bile to break down fats and removes toxins. Location: Upper right side of the abdomen, above the stomach.

Question 31

What is the function of the gall bladder, and where is it found?

Answer 31

Function: Stores and releases bile to help digest fats. Location: Beneath the liver.

Question 32

Describe Ingestion

Answer 32

Ingestion — the taking of substances, ex. Food and drink, into the body.

Question 33

Describe Digestion

Answer 33

Digestion — the breakdown of food

Question 34

Describe Absorption in the digestive system

Answer 34

Absorption — the movement of nutrients from the intestines into the blood

Question 35

Describe Assimilation

Answer 35

Assimilation — uptake and use of nutrients by cells

Question 36

Describe Egestion

Answer 36

Egestion — the removal of undigested food from the body as faeces.

Question 37

Why is physical digestion important?

Answer 37

It increases the surface area of food, making it easier for enzymes to act.

Question 38

What is chemical digestion?

Answer 38

The breakdown of large, insoluble molecules into small, soluble molecules using enzymes.

Question 39

Why is chemical digestion important?

Answer 39

It produces small, soluble molecules that the body can absorb into the bloodstream.

Question 40

What does the amylase enzyme do?

Answer 40

Amylase breaks down starch to simple reducing sugars. Tip : Remember Amylase—Amylum (Starch)

Question 41

What does the protease enzyme do?

Answer 41

Proteases break down protein to amino acids. Tip : Remember Protease—Protein

Question 42

What does the lipase enzyme do?

Answer 42

Lipase breaks down fats and oils to fatty acids and glycerol. Tip : Remember Lipase—Lipids (Fats)

Question 43

Where is amylase secreted, and where does it act?

Answer 43

Secreted by: Salivary glands & pancreas. Acts in: Mouth & small intestine. Function: Breaks down starch into sugars.

Question 44

Where is protease secreted, and where does it act?

Answer 44

Secreted by: Stomach & pancreas. Acts in: Stomach & small intestine. Function: Breaks down proteins into amino acids.

Question 45

Where is lipase secreted, and where does it act?

Answer 45

Secreted by: Pancreas. Acts in: Small intestine. Function: Breaks down fats into fatty acids & glycerol.

Question 46

What are the functions of hydrochloric acid in the stomach?

Answer 46

It kills harmful microorganisms in food, and provides an acidic pH for protease enzymes to work properly.

Question 47

Why is bile important for digestion?

Answer 47

It neutralizes stomach acid in the duodenum, creating the right pH for enzyme action.

Question 48

How does bile help with fat digestion?

Answer 48

Bile emulsifies fats, breaking them into smaller droplets to increase surface area for enzyme action.