Plant Nutrition

Question 1

Plants require macronutrients and micronutrients for what?

Answer 1

Their metabolism.

Question 2

Why are essential elements important?

Answer 2

• necessary for normal growth and development
• cannot be functionally replaced by a different element
• has one or more roles in plant metabolism

Question 3

What are the nine essential macronutrients?

Answer 3

C, H, O, N, Ca, Mg, K, P, S

Question 4

What percent of dry mass comes from air and water?

Answer 4

roughly 96%

Question 5

Micronutrients are essential in what trace quantity?

Answer 5

<200 ppm

Question 6

What are the micronutrients?

Answer 6

Ni, Cu, Mo, Mn, Zn, Fe, Cl, B

Question 7

What is chlorosis?

Answer 7

Loss of green colouration

Question 8

Roots also secreting substances into the soil helps us understand what?

Answer 8

How plants adapted to obtain nutrients and fight disease

Question 9

Mycorrhizae and nitrogen-fixing bacteria are both…

Answer 9

Adaptive interactions that increase plant access to scarce nutrients.

Question 10

Characteristics of roots:

Answer 10

• Makeup 20-50% of total plant mass

– Roots grow continuously

Question 11

Roots mechanisms to increase uptake

Answer 11

• Root hairs
  – Membrane transporters
  – Mycorrhizae

Question 12

Is transpiration active or passive?

Answer 12

Passive

Question 13

Some mineral ions enter root cells immediately through this route…

Answer 13

Symplastic route

Question 14

Some minerals travel between cells until they meet the endodermis…

Answer 14

apoplastic route

Question 15

inside most cells minerals enter:

Answer 15

vacuoles or cell cytoplasm

Question 16

some ions move through:

Answer 16

the phloem

Question 17

Nitrogen is:

Answer 17

– Abundant element in air, most limiting to plant
– Triple bond requires nitrogenase enzyme
– Nitrogen cycle provides soil nitrogen

Question 18

Nitrogen fixation does what?

Answer 18

incorporates atmospheric N2 into plant-available compounds (ammonum)

Question 19

What is the Haber-Bosch Process?

Answer 19

an industrial process for producing ammonia from nitrogen and hydrogen, using an iron catalyst at high temperature and pressure.

Question 20

What does the Haber-Bosch process depend on?

Answer 20

Petroleum

Question 21

By what percent did the Haber Bosch process increase the population?

Answer 21

40%

Question 22

Most nitrogen is fixed by what?

Answer 22

plant symbioses with bacteria

Question 23

How are plants and bacteria mutally beneficial?

Answer 23

Plant provides organic molecules for

respiration energy, bacteria provide NH4+

Question 24

Legumes form root nodules with:

Answer 24

Rhizobium or

Bradyrhizobium

Question 25

How are bacterial nod genes expressed?

Answer 25

with flavonoid signal from plants

Question 26

Infection thread allows for what?

Answer 26

Bacterial invasion

Question 27

Bacteroids are…

Answer 27

enclosed in nodule and are integrated into the root system

Question 28

Examples of atypical nutrient aquisision:

Answer 28

Cobra lily, Dodder, Snow plant, Lady-of-the-night orchid

Question 29

What take only physical support from host plants?

Answer 29

Epiphytes