Plant Root

Question 1

Functions of roots:
stability and proper orientation

Answer 1

Anchorage

Question 2

Functions of roots:
cylindrical shape that is ideal for what?

Answer 2

Absorption

Question 3

Functions of roots:
sink organs; mostly sugars and water

Answer 3

storage

Question 4

Functions of roots:
mycorrhiza; nutrient exchanges

Answer 4

Interaction with other organisms

Question 5

Functions of roots:
produce cytokinin and gibberellin imported to the shoot system

Answer 5

Hormone production

Question 6

Root system:
develops from radicle and emerges with lateral or branching roots; common in eudicots; primary root grows downward

Answer 6

Taproot

Question 7

Root system:
arises when radicle dies during or immediately after germination; no primary root

Answer 7

Fibrous root

Question 8

External structures of roots:
extreme tip pushes through soil

Answer 8

Root tip

Question 9

External structures of roots:
formed by terminal parenchyma, protects RAM, must always be renewed and secretes mucigel for lubrication

Answer 9

Root cap

Question 10

External structures of roots:
greatly increase root’s surface area, not lateral roots!

Answer 10

Root hairs

Question 11

External structures of roots:
root epidermis, lack stomata, produces mucigel, no cuticle, with root hairs, NOT root periderm

Answer 11

Rhizodermis/epiblem

Question 12

Rhizodermal cells:
give rise to root hairs

Answer 12

Trichoblasts

Question 13

Rhizodermal cells:
do not produce root hairs

Answer 13

Atrichoblasts

Question 14

Rhizodermal cells:
contains exodermis, with heavily sclerified cells

Answer 14

Velamen

Question 15

Internal structure of roots:
site of gravisensing, has amyloplasts that settle in response to gravity

Answer 15

Columella

Question 16

Internal structure of roots:
amyloplasts of columella cells

Answer 16

Statoliths

Question 17

Internal structure of roots:
statolith-containing cells of columella cells

Answer 17

statocysts

Question 18

Internal structure of roots:
buried under root cap

Answer 18

Root apical meristem

Question 19

Internal structure of roots:
can resist radiation and toxic chemicals and act as reserve for healthy cells when root cap is damaged

Answer 19

quiescent center

Question 20

Internal structures of roots:
enlargement of cells, cells differentiate but don’t mature

Answer 20

Zone of elongation

Question 21

Internal structures of roots:
three tissues in zone of elongation

Answer 21

Protoderm, ground meristem, procambium

Question 22

Internal structures of roots:
root hairs grow outward, thin cuticle appears to be present, cortex enlarges to transfer minerals from epidermis to vascular tissues

Answer 22

Zone of maturation

Question 23

Internal structures of roots:
outer most region

Answer 23

rhizodermis

Question 24

Internal structures of roots:
ground tissues between rhizodermis and vascular tissues derived from ground meristems

Answer 24

root cortex

Question 25

Internal structures of roots: innermost cortical layer with casparia strip

Answer 25

endodermis

Question 26

Route of transportation: upatek by hydrophilic walls of rot hairs provide access to apoplasts

Answer 26

Apoplastic route

Question 27

Route of transportation: minerals and water cross plasma membrane of root hairs and can enter symplasts

Answer 27

Symplastic route

Question 28

Route of transportation: minerals and water move through cell wall and plasma membrane

Answer 28

Transmembrane route

Question 29

Route of transportation: water and minerals is stopped by casparian strip

Answer 29

Endomembrane route

Question 30

Internal structures of roots: parenchymal cells between endodermis and vascular tissues that give rise to lateral roots

Answer 30

Pericycle

Question 31

Internal structures of roots: central vascular cylinder of root and holds vascular bundles, pericylce, and some parenchymal cells.

Answer 31

Stele

Question 32

Xylem forms solid mass at the center surrounded by phloem; no pith

Answer 32

eudicot stele

Question 33

First vascular tissues to emerge

Answer 33

Protoxylem and protophloem

Question 34

Second vascular tissues to emerge

Answer 34

Metaxylem and metaphloem

Question 35

Xylem and phloem are distributed and scattered in ground tissues ~ atactostele

Answer 35

Monocot stele

Question 36

Root modification: found in tropical tree roots, become tall and plate like, braces trunk against wind

Answer 36

Buttress

Question 37

Root modification: commonly found in mangroves subjected to strong water currents and provides stability

Answer 37

Brace roots

Question 38

Root modification: common in monocots. When stem widens, adventitious roots extend to soil and helps aeration of roots submerged in low-oxygen substrate

Answer 38

Prop roots

Question 39

Root modification: attached to branches of trees and sometimes dangling in the air

Answer 39

Clinging roots

Question 40

Root modification: perched on branched and rapidly grows, hugging the tree

Answer 40

Strangling/drop roots

Question 41

Root modification: Only permanent organ in plant, carbohydrates stored in roots to grow new shots

Answer 41

Food storage

Question 42

Root modification: common in desert plants, swollen to store water and pulls plant to soil to protect from over exposure to the sun

Answer 42

Water storage

Question 43

Root modification: found in bulbous plants, shoot may be buried because root pulls plant down but keeps plant upright and anchored

Answer 43

Contractile roots

Question 44

Root modification: bacteria inside can convert atmospheric Nitrogen into compounds for plant use

Answer 44

Nodular

Question 45

Root modification: may possess spines to deter herbivores

Answer 45

Protection

Question 46

Root modification: allows root to perform gas exchange, common in mangrove

Answer 46

Aeration

Question 47

Root modification: chlorophyllous roots capable of photosynthesis, common in aerated orchid roots

Answer 47

Photosynthesis

Question 48

Root modification: adventitious roots that give rise to another plant

Answer 48

Reproduction

Question 49

Root modification: penetration of host using haustoria and the fusion of vascular tissues between plant and parasite

Answer 49

Parasitism

Question 50

Root modification: symbiotic association where fungus is protected and get sugars and complex molecules for plant

Answer 50

Mychorriza