Review 8

Question 1

Roots provide a large surface area for

Answer 1

mineral ion and water uptake by means of branching and root hairs

Question 2

Monocots

Answer 2

fibrous, highly branched roots to increase surface area

Question 3

Dicots

Answer 3

deep taproots (lots of access to resources) with lateral branches (increase surface area)

Question 4

Root hairs

Answer 4

further increase surface area and provide pumps for active transport (lots of mitochondria)

Question 5

Mineral ions in the soil move into the root PASSIVELY…

Answer 5

Diffusion: flow down a concentration gradient into root
Fungal hyphae: symbiotic relationship (fungus absorbs minerals for plant in exchange for sugars)
Mass flow: water flows into plant INTO high solute concentrations by osmosis (creates negative pressure in soil around root); minerals hydrogen bond to water and move passively with water into plant

Question 6

Diffusion:

Answer 6

flow down a concentration gradient into root

Question 7

Fungal hyphae:

Answer 7

symbiotic relationship (fungus absorbs minerals for plant in exchange for sugars)

Question 8

Mass flow:

Answer 8

water flows into plant INTO high solute concentrations by osmosis (creates negative pressure in soil around root); minerals hydrogen bond to water and move passively with water into plant

Question 9

Mineral ions in the soil move into the root Actively

Answer 9

*Protein pumps in root cells (lots of mitochondria) actively transport mineral ions against concentration gradient (like potassium ions) OR *Protein pumps actively pump H+ ions into surrounding soil (these bind to negatively charged ions in soil and diffuse back into root with H+ ions); displaces (forces out) positively charged minerals from clay so they can be absorbed (diffusion) into root cells – this is INDIRECT active transport

Question 10

ROOT STRUCTURE:

Answer 10

Epidermis: protection; root hairs increase surface area for absorption
Cortex: transports (diffusion) water/ ions to stele (vascular tissue)
Stele
Endodermis/ Casparian Strip: impermeable to water and ions; controls rate of uptake – must be pumped
Pericycle/ cambium: lateral root development Vascular bundle
Xylem (X-shaped; water and mineral ion transport from roots to stems to leaves)
Phloem (phloem = more out/ surrounding xylem; sugar and amino acid transport)

Question 11

Epidermis

Answer 11

protection; root hairs increase surface area for absorption

Question 12

Cortex:

Answer 12

transports (diffusion) water/ ions to stele (vascular tissue)

Question 13

Endodermis/ Casparian Strip:

Answer 13

impermeable to water and ions; controls rate of uptake – must be pumped

Question 14

Pericycle/ cambium:

Answer 14

lateral root development

Question 15

Xylem

Answer 15

X-shaped; water and mineral ion transport from roots to stems to leaves

Question 16

Phloem

Answer 16

phloem = more out/ surrounding xylem; sugar and amino acid transport