ROOT AND MINERAL NUTRITION

Question 1

branching underground root system are often more ______ than the aerial parts

Answer 1

extensive

Question 2

2 main functions of roots

Answer 2

• anchors a plant in the soil

- absorbs needed water and minerals

Question 3

two types of root system

Answer 3

TAPROOT SYSTEM

FIBROUS ROOT SYSTEM

Question 4

differentiate taproot system from fibrous root system

Answer 4

taproot system consists of one main root, then many lateral roots branch out of the taproot. the main root come from the seedling’s embryonic root or radicle (characteristic of eudicots and gymnosperms)

fibrous root system consists of many roots of similar size, with lateral roots branching off these roots. the main roots arise from the stem itself
(characteristic of monocots)

Question 5

the taproot system consists of one main root formed from the seedling’s what?

Answer 5

embryonic root (RADICLE)

Question 6

these cells secrete lubricating polysaccharide to reduce friction

Answer 6

ROOT CAP CELLS

Question 7

these cells help orient the root so that it grows downward

Answer 7

ROOT CAP CELLS

Question 8

short-lived tubular extensions (trichromes) of epidermal cells located just behind the growing root tip

Answer 8

ROOT HAIRS

Question 9

the absorptive capacity increasing by surface area is caused by these trichromes

Answer 9

ROOT HAIRS

Question 10

a single layer of protective ______ covers roots

Answer 10

epidermis

Question 11

root hairs and no cuticle increase _________

Answer 11

absorption

Question 12

most water that enters the root moves along what

Answer 12

cell walls made of cellulose

Question 13

the _______ composes most of the root

Answer 13

cortex

Question 14

roots usually lack supporting _________ cells, but may develop some __________ as they age

Answer 14

collenchyma; sclerenchyma

Question 15

the primary function of root cortex is _________

Answer 15

starch storage

Question 16

in a root cortex, ______________ provide a pathway for water intake and allow aeration of the root

Answer 16

large intercellular spaces

Question 17

in a root cortex, water and dissolved minerals move along two pathways:

Answer 17

SIMPLEST PATHWAY: living cells interconnected by plasmodesmata
APOPLAST PATHWAY: uses cell walls and intercellular spaces

Question 18

the ___________ regulates movement of water and minerals that enter the xylem

Answer 18

ENDODERMIS

Question 19

_________ cells fit tightly against one another – each cell has a _____________ on its radial and transverse walls that contains a waterproof material (_________)

Answer 19

endodermal; CASPARIAN STRIP; suberin

Question 20

a band of cell wall material deposited in the radial and transverse walls of the endodermis (the cell walls are mostly made of suberin instead of lignin)

Answer 20

CASPARIAN STRIP

Question 21

these prevent water and minerals from continuing to move passively along the cell walls

Answer 21

CASPARIAN STRIP

Question 22

these are at the center of a eudicot primary root

Answer 22

STELE

Question 23

this is inside the endodermis; consists of a single layer of parenchyma cells that give rise to lateral meristems/roots

Answer 23

PERICYCLE

Question 24

a lateral root pushes through what before entering the soil

Answer 24

several layers of root tissue

Question 25

the centermost tissue of the stele; often has two or more extensions

Answer 25

XYLEM

Question 26

these are the patches between the xylem arms in the stele

Answer 26

PHLOEM

Question 27

these conduct dissolved sucrose in the roots

Answer 27

SIEVE TUBE ELEMENTS

Question 28

is sandwiched between the xylem and phloem in the stele

Answer 28

VASCULAR CAMBIUM

Question 29

how does monocot roots differ from eudicot roots

Answer 29

the phloem and xylem are in separate, alternating bundles arranged around the central pith of parenchyma cells;
no vascular cambium exists in monocot roots

Question 30

___________ and ____________ have primary growth at apical meristems and secondary growths at lateral meristems

Answer 30

GYMNOSPERMS and WOODY EUDICOTS

Question 31

woody plants have roots with ___________ growth

Answer 31

SECONDARY

Question 32

roots specialized for unusual functions

Answer 32

PROP ROOTS
BUTTRESS ROOTS
PNEUMATOPHORES
AERIAL ROOTS