Plant Growth and Roots

Question 1

Indeterminate Growth

Answer 1

Ability to grow to genetically unspecified size throughout life

Question 2

Totipotency

Answer 2

Ability of cell to give rise to :
any cell or tissue type
generate and organ
clone an organism

Question 3

Meristem

Answer 3

Region of undifferentiated, totipotent, parenchyma cells

Function: to divide

Question 4

Types of meristamatic regions for primary growth

Answer 4

Apical meristems

Primary meristems

Question 5

Types of meristamatic regions for secondary growth

Answer 5

Vascular cambium

Phellogen

Question 6

Initials

Answer 6

small, undifferentiated, totipotent cells

-Divides and remains part of meristem

Question 7

Derivatives

Answer 7

Totipotent
Can: divide again
-grow
-Differentiate

Question 8

Positional Info

Answer 8

How cells know what to become

-chemical and environmental signals

Question 9

Where does primary growth occur?

Answer 9

In all organs and all plants

Question 10

Where does secondary growth occur

Answer 10

Roots and stems in some plants

Question 11

Apical Meristem

Answer 11

Meristem at the tip of root or stem

-Divisions give rise to primary meristems

Question 12

Primary meristem

Answer 12

Divisions give rise to primary tissue systems

Question 13

Vascular Cambium

Answer 13

Layer of meristematic cells b/w phloem and xylem

Question 14

Derivatives of vascular cambium produce

Answer 14

-secondary phloem on phloem side
-secondary xylem on xylem side
(5x more xylem than phloem)

Question 15

Functions of Roots (5)

Answer 15

1. Anchor plant
2. Absorb and conduct water
3. Control movement of water and ions
4. Starch storage
5. Detect gravity

Question 16

Root Zones (4)

Answer 16

1. Rootcap
2. Region of cell division
3. Region of Elongation
4. Region of Maturation

Question 17

Rootcap

Answer 17

Mass of short lived parenchyma cells that cover tip of root

Question 18

Functions of rootcap (3)

Answer 18

1. Secrete mucigel
2. Protect apical meristem
3. Orient plant growth

Question 19

Zone of Division

Answer 19

Has apical meristem and primary meristem

-Divides

Question 20

Zone of Elongation

Answer 20

Derivatives of meristems elongate
Primary growth
-pushes rootcap and meristems through the soil

Question 21

Zone of Maturation

Answer 21

Cells and tissues differentiate

-Root hairs

Question 22

Root Hairs

Answer 22

• extension of epidermal cells
• short lived
• in zone of maturation
• increase absorptive surface area and absorb water and ions

Question 23

Epidermis function and structure

Answer 23

Absorb minerals and water

-thin cuticle and root hairs

Question 24

Cortex

Answer 24

Ground tissue system of parenchyma located b/w epidermis and vascular cylinder

Question 25

Function and structure of cortex

Answer 25

1. Storage--prominent amyloplasts 2. Circulation of air--aerenchyma 3. Control water into vascular cylinder--endodermis

Question 26

Apoplastic movement

Answer 26

Through intercellular spaces and along the primary cell walls -doesn't cross a membrane (not filtered)

Question 27

Symplastic Movement

Answer 27

From cell to cell through plasmodesmata

Question 28

Transcellular

Answer 28

Through vacuoles, cell membranes, and walls

Question 29

Endodermis

Answer 29

Innermost layer of cortex - densely packed parenchyma - casparian strips - made of suberin (waxy) - controls water into vascular cylinder

Question 30

Casparian Strips

Answer 30

Endodermis - block apoplastic flow of water - force water through plasmalemma

Question 31

Vascular Cylinder regions (3)

Answer 31

Pericycle Primary xylem Primary phloem

Question 32

Pericycle

Answer 32

``` Outermost layer of v. Cylinder Parenchyma cells that can give rise to more -give rise to lateral roots -contributes to vascular cambium -give rise to cork cambium and periderm ```

Question 33

Lateral Roots

Answer 33

- Branch roots - Endogenous formation - Originate in pericycle - Punch their way out

Question 34

Taproot System

Answer 34

Primary root long lived - Grows deep w/ branches coming off - 2° growth common - Dicots

Question 35

Fibrous Root System

Answer 35

Primary root short lived - Network of adventitious roots and lateral roots - Shallow and bind soil - 2° growth absent - Monocots

Question 36

Storage Roots

Answer 36

- Primary roots w/ large storage cortex - Secondary roots: mostly storage parenchyma - Carrots, radishes

Question 37

Adventitious Roots

Answer 37

Roots that grow from an organ other than another root | -Includes prop roots that help keep a plant upright

Question 38

Aerial Roots

Answer 38

- Epiphytes - Absorb water and ions out of air - May be photosynthetic

Question 39

Epiphyte

Answer 39

Non-parasitic plant that grows on another plant | -Orchids

Question 40

Velamen

Answer 40

Multi-layered epidermis - absorbs water and ions - Specialized tissue in some orchids

Question 41

Haustorium

Answer 41

Modified root of parasitic plants - Pierces host - Connects to vascular system of the plant - Dodder and Haustoria