Test 3 Review: Plant Nutrition

Question 1

What structural elements account for 96% of a plant’s mass?

Answer 1

C, H, O

Question 2

What are the sources of elements that account for 96% of a plant’s mass?

Answer 2

C from CO2
H from H2O
O from CO2 and H2O

Question 3

What determines that a nutrient is an essential plant nutrient?

Answer 3

Plant cannot complete life cycle without it – if present in insufficient amounts, plant may exhibit deficiency symptoms

Question 4

Other than availability of a nutrient, what three factors need to be considered?

Answer 4

Binding and leeching of nutrient
Assimilation of nutrient
Rhizosphere interactions

Question 5

What value is it to a plant to be a hyperaccumulator of a particular nutrient?

Answer 5

May be a deterrent to herbivory

Question 6

What value is it to a human that plants can be hyperaccumulators of particular nutrients?

Answer 6

Plants that accumulate nutrients that provide health benefits can lead to them being considered “super foods”

Phytoremediation– removing toxic metals from environment

Question 7

Nitrogen fixation is classified as what kind of chemical reaction?

Answer 7

Reduction

Question 8

To what forms must N2 be converted to be accessible to plants?

Answer 8

Ammonium ion (NH4+)
Nitrate (NO)

Question 9

What enzyme catalyzes N2 fixation?

Answer 9

Nitrogenase

Question 10

What two enzymes make up nitrogenase?

Answer 10

Dinitrogen reductase
Dinitrogenase

Question 11

What else needs to be available (other than N2) for nitrogenase to work?

Answer 11

Significant amounts of ATP (18 per nitrogen fixed)

Question 12

What is the major source for phosphate fertilizer

Answer 12

Mining of phosphate-containing rocks

Question 13

What are some alternative organic sources?

Answer 13

Animal waste

Question 14

What three plant modifications and associations are related to the uptake of phosphorous?

Answer 14

Cluster roots
Exudates
Mycorrhizal associations