Chapter 2 - plant nutrition

Question 1

What is the definition of photosynthesis

Answer 1

The process by which plants manufacture carbohydrates from raw materials using energy from light

Question 2

What is glucose made in photosynthesis used for

Answer 2

• Making starch, by linking glucose molecules together, this is stored in plant cells
• Make cellulose; by linking glucose molecules together; it is used to make cell walls
• Make sucrose; used to transport carbohydrates from one part of a plant to another
• Make lipids; by rearranging the carbon, hydrogen and oxygen atoms and adding nitrogen to make amino acids

Question 3

What is the definition of a limiting factor

Answer 3

Something present in the environment in such short supply that it restricts a life process

Question 4

In daylight do respiration and photosynthesis occur at the same rate

Answer 4

• No
• Photosynthesis occurs at a greater rate than respiration

Question 5

What indicator can be used to investigate the effects of gas exchange in an aquatic plant

Answer 5

• Hydrogencarbonate indicator
• Yellow is lots of CO2
• Red or purple is little or no CO2

Question 6

• Why does the upper epidermis not have chloroplasts
• Why does it secrete a waxy cuticle

Answer 6

• So light passes through to the palaside cells
• The waxy cuticle prevents water loss from the leaf surface

Question 7

What adaptations help most photosynthesis to take place in the palaside cells

Answer 7

• Palaside cells are near the top of the leaf so they get lots of sunlight
• Many chloroplasts for phtosynthesis
• Have air spaces close to them for carbon dioxide

Question 8

What are the adaptations for photosynthesis to sometimes take place in the spongy mesophyll cells

Answer 8

• Large air spaces to provide carbon dioxide as it can diffuse to the palaside cells from the stomata
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Question 9

How does carbon dioxide diffuse into the plant

Answer 9

• Enters via diffusion through the stomata
• The guard cells can shape to open or close the stomata

Question 10

What do nitrate ions do

Answer 10

Needed to make amino acids, which are used to make proteins

Question 11

What do magnesium ions do

Answer 11

Used to make chlorophyll

Question 12

In what cells are chloroplasts found

Answer 12

• Palaside cells
• Spongy mesophyll cells
• Guard cells

Question 13

What does nitrate ion deficiency cause

Answer 13

Weak growth as not enough amino acids are made to be made into proteins

Question 14

What does magnesium ion deficiency cause

Answer 14

Yellow leaves as there is not enough chlorophyll for photosynthesis to take place