Nutrition

Question 1

What are mineral ions used for in plants?

Answer 1

Mineral ions are used for growth in plants.

Question 2

What are symptoms of nitrate deficiency in plants?

Answer 2

Yellowing leaves and stunted growth.

Question 3

How does gas exchange occur in plants?

Answer 3

Gas exchange occurs via the stomata; carbon dioxide diffuses into the leaves while oxygen diffuses out.

Question 4

How is the palisade mesophyll layer adapted for photosynthesis?

Answer 4

The palisade mesophyll layer contains tall, thin cells that pack closely together. These cells contain many chloroplasts to maximize light absorption.

Question 5

Explain the effect of temperature on photosynthesis.

Answer 5

As temperature increases, so does the rate of photosynthesis. Once the temperature exceeds the optimum, the rate of photosynthesis decreases as enzymes begin to denature.

Question 6

How do plants obtain mineral ions like nitrates and magnesium?

Answer 6

Plants obtain mineral ions like nitrates and magnesium by active transport from the root hair cells.

Question 7

What is a symptom of magnesium deficiency in plants?

Answer 7

Yellowing between leaf veins.

Question 8

How do plants store chemical energy?

Answer 8

Plants store chemical energy as starch, which is made from glucose produced during photosynthesis.

Question 9

What is the role of the guard cell?

Answer 9

The guard cell can change shape to open or close the stomata. This allows plants to control the rates of water loss from leaves.

Question 10

How do plants synthesize starch?

Answer 10

Plants synthesize starch through photosynthesis, where they convert carbon dioxide and water into glucose and oxygen. The glucose is then linked together to form starch.

Question 11

Why do very high temperatures cause photosynthesis to stop?

Answer 11

The enzymes that control photosynthesis denature, meaning that the reaction can no longer take place.

Question 12

What is the purpose of boiling the leaf in ethanol and testing for starch?

Answer 12

To remove chlorophyll, to allow the results of the starch test to be seen more clearly.

Question 13

What is the purpose of the de-starching step in photosynthesis experiments?

Answer 13

The purpose of de-starching the plant by placing it in the dark for 24 hours is to ensure any pre-existing starch in the leaves is used up so it doesn’t affect the results.

Question 14

How could you test for the evolution of oxygen gas in photosynthesis using a water plant?

Answer 14

By placing a water plant underwater and collecting bubbles of oxygen gas using an upturned funnel and a boiling tube. The presence of oxygen can be tested by relighting a glowing splint in the gas collected.

Question 15

What are nitrate ions needed for?

Answer 15

For the production of amino acids which are joined together to build proteins.

Question 16

Why do plants need magnesium ions?

Answer 16

For the production of chlorophyll.

Question 17

Name two essential mineral ions required by plants.

Answer 17

Nitrates, magnesium ions.

Question 18

Why is it beneficial for leaves to be broad while having a thin cross-section?

Answer 18

Being broad maximizes surface area for light absorption. Being thin reduces diffusion distance for gas exchange.

Question 19

How is the spongy mesophyll layer adapted for photosynthesis?

Answer 19

By having lots of air spaces which increases surface area for efficient gas exchange.

Question 20

What is the effect of carbon dioxide concentration on the rate of photosynthesis?

Answer 20

As the concentration of carbon dioxide increases, so does the rate of photosynthesis. This continues until another factor becomes limiting.

Question 21

Explain the effect of light intensity on photosynthesis.

Answer 21

As light intensity increases, so does the rate of photosynthesis. This continues until another factor becomes limiting.

Question 22

What are the three main factors that limit the rate of photosynthesis?

Answer 22

Temperature, light intensity, carbon dioxide concentration.

Question 23

Define the term limiting factor in the context of photosynthesis.

Answer 23

A factor that limits the rate of photosynthesis.

Question 24

What is the symbol equation for photosynthesis?

Answer 24

6CO2 + 6H2O -> C6H12O6 + 6O2.

Question 25

What type of organisms use photosynthesis to make their own food?

Answer 25

Producers.

Question 26

What is the role of the waxy cuticle?

Answer 26

The waxy cuticle is a waterproof layer that reduces water loss by evaporation from the surface of leaves.

Question 27

How is glucose used in plant cells?

Answer 27

Respiration, storage in the form of starch, the production of cellulose cell walls, conversion into lipids and amino acids.

Question 28

What is the alimentary canal?

Answer 28

The complete tube that passes food through as it moves through the body.

Question 29

What are the two parts of the small intestine?

Answer 29

Duodenum: Receives food directly from the stomach and produces digestive enzymes to complete digestion. Ileum: Absorbs nutrients from the food into the blood.

Question 30

What is the function of the large intestine?

Answer 30

Absorbs excess water from solid waste. The remaining solid waste is feces.

Question 31

Describe the test for the energy content of a food sample.

Answer 31

1. Measure 25 cm³ of water using a measuring cylinder and add it to a boiling tube. 2. Record the initial temperature of the water using a thermometer. 3. Record the mass of the food sample using a scale. 4. Set fire to the food using a Bunsen burner and hold the sample under the boiling tube until it is completely burnt (relight if needed). 5. Record the final temperature of the water. 6. Calculate the energy in the food.

Question 32

What is the equation to calculate the energy content in food?

Answer 32

Energy (J) = Mass of water (g) × Temperature change (°C) × 4.2 | Energy (J/g) = Energy in food ÷ Mass of food

Question 33

What is vitamin A used for?

Answer 33

Needed for the production of pigment in the retina for good vision, keeping skin and hair healthy, and strengthening the immune system.

Question 34

Name three sources of vitamin A.

Answer 34

Liver, carrots, eggs.

Question 35

What is vitamin C used for?

Answer 35

Growth and repair of tissues.

Question 36

What are minerals?

Answer 36

Chemical elements essential for many processes in the body.

Question 37

Name the organs of the alimentary canal in order.

Answer 37

Mouth, esophagus, stomach, small intestine, large intestine, rectum.

Question 38

What three features of villi aid absorption?

Answer 38

Large surface area, thin walls/short diffusion distance, well supplied with blood capillaries.

Question 39

Define a balanced diet.

Answer 39

A balanced diet consists of all essential nutrients in their correct proportions.

Question 40

What is the function of lipids in the body?

Answer 40

Act as an energy store, protect vital organs, and reduce heat loss.

Question 41

Name two examples of minerals needed in our diet.

Answer 41

Calcium, iron.

Question 42

What is the function of calcium in the body? Name two sources.

Answer 42

Function: To make and strengthen bones and teeth. | Sources: Dairy, leafy green vegetables.

Question 43

What does not having a balanced diet lead to?

Answer 43

Malnutrition, deficiency, and/or excess.

Question 44

What is the function of carbohydrates in the body?

Answer 44

Main source of energy.

Question 45

What are proteins needed for in the body?

Answer 45

Growth and repair.

Question 46

Name three examples of carbohydrates.

Answer 46

Pasta, rice, potatoes.

Question 47

Name three examples of proteins.

Answer 47

Meat, fish, dairy.

Question 48

Name three examples of lipids.

Answer 48

Butter, cheese, nuts.

Question 49

Name two sources of vitamin C.

Answer 49

Fruits, vegetables.

Question 50

What is dietary fiber used for?

Answer 50

Aids the movement of food along the gut.

Question 51

What is the function of the mouth?

Answer 51

Produces amylase to break down starch into maltose (via salivary glands). Teeth break down food.

Question 52

What is the function of the esophagus?

Answer 52

Muscular tube that carries food from the mouth to the stomach via peristalsis.

Question 53

What role does the pancreas play in digestion?

Answer 53

Secretes protease, amylase, and lipase into the small intestine.

Question 54

What is the function of the rectum?

Answer 54

Stores feces before digestion.

Question 55

What does lipase do?

Answer 55

Breaks lipids into glycerol and fatty acids.

Question 56

What does protease do?

Answer 56

Breaks protein into amino acids.

Question 57

What do amylase and maltase do?

Answer 57

Amylase breaks down starch into maltose. | Maltase breaks down maltose into glucose.

Question 58

What is the function of bile?

Answer 58

Emulsifies fats to increase surface area for lipase and neutralizes stomach acid to provide alkaline conditions for enzymes in the small intestine.

Question 59

Where is bile produced and stored?

Answer 59

Produced in the liver and stored in the gallbladder.

Question 60

How is the ileum adapted for absorption?

Answer 60

Lined with villi, providing a large surface area for absorption.

Question 61

Name two sources of vitamin D.

Answer 61

Sunlight, eggs.

Question 62

What is vitamin D used for?

Answer 62

Calcium absorption.

Question 63

What are the key components of a balanced diet?

Answer 63

Carbohydrates, proteins, lipids, dietary fiber, vitamins, minerals, water.

Question 64

What is iron used for in the body? Name two sources.

Answer 64

Function: Production of hemoglobin to transport oxygen in blood. | Sources: Red meat, eggs.

Question 65

What is water used for in the body?

Answer 65

Essential for almost every bodily function.

Question 66

What factors influence an individual’s energy requirements?

Answer 66

Activity levels, age, gender, pregnancy.

Question 67

What is the function of the stomach?

Answer 67

Pummels food with muscular walls, produces pepsin to break down proteins, and produces hydrochloric acid to kill bacteria and provide optimal pH for enzymes.

Question 68

Define peristalsis.

Answer 68

Wave-like muscle contractions that push food along the alimentary canal.