Root

what are the primary functions of roots?

• anchorage

• absorption

• storage

• conduction

what is the traproot system?

taproot, primary root developed from the radicle, gives rise to branch/lateral roots

do eudicots have taproots or fibrous roots?

taproots

do monocots have taproots or fibrous root 

fibrous root

what is the fibrous root system?

main root system develops from the stem, no prominent root 

what is the record depth of penetration by roots?

175 feet

what are the root caps?

thimble-shaped mass of living parenchyma cells covering each root tip 

what are the functions of the root cap?

• protects tissue from damage

• function in gravity perception (columella) 

• lubricate the roots (mucigel) 

the region of cell division is composed of ____________ in the center of the root tip.

apical meristem

most cell division occurs at the edge of the _____________.

inverted cup-shaped zone

at the region of cell division, what type of cell are there?

cuboidal cells w nuclei in the center, and a few very small vacuoles 

what are the three meristematic regions to cell division?

protoderm 

ground meristem 

procambium 

what does the protoderm become?

dermal tissue (epidermis)

what does the ground meristem become?

ground tissue (parenchyma cells, collenchyma cells, sclerenchyma cells) 

what does the procambium become?

vascular tissues (primary xylem and phloem)

what is the region of elongation?

region where cells become several times their original length

• vacuoles merge 

what is the region of maturation?

where most cells differentiate into various distinctive cell types

what is the function of the region of maturation?

absorb water and minerals and adhere tightly to soil particles 

• thin cuticle 

root hair form at the region of __________.

maturation

what does the cortex store?

mostly food

the cortex is composed of what?

parenchyma cells

the cortex contains the __________.

endodermis: a single layer of tightly packed cells

the cell walls of the region of maturation are impregnated with ___________

suberin bands, casparian strips

what is the function of suberin bands and casparian strips?

forces all water and dissolved substances entering and leaving the central core to pass through plasma membranes of the endodermal cells 

because of the casparian strips water can NOT move through or between what?

the cell wall 

in eudicots, 2/3 of the plant is composed of:

cortex

the vascular cylinder is another part of the region of maturation, where is it located?

at the inside of the endodermis (composed of xylem and phloem) 

where is the pericycle located?

lies directly against the inner boundary of the endodermis

what is the pericycle composed of?

meristematic cells

the pericycle gives rise to:

lateral roots

what are the different types of specialized roots?

• food storage roots 

• water storage roots 

• pneumatophore 

• aerial root 

• parasitic root

what is the function of food storage roots and what are some examples of plants with this root?

with enlarged roots

store starch and carbs

• sweet potato, sugar beet, carrots

water storage roots are common in what family?

the pumpkin family

• common in arid regions

what is the function of pneumatophores?

spongy roots that extend above the water’s surface and enhance gas exchange between the atmosphere and subsurface roots

what are some examples of pneumatopores?

bald cypress, tropical mangroves

what plants have aerial roots?

valeman roots of orchids

prop roots of corn and banyan trees 

what is the function of aerial roots?

stabilization of the plant 

what is the function of parasitic roots?

have no chlorophyll and are dependent on chlorophyll-bearing plants for nutrition

• ex: dodder

what is the peglike structure of parasitic roots that penetrates the tissues of the host plant called?

haustoria