UNIT 10: ROOTS

Study Questions  Lecture Outline
Return to Bio 205 Main Page

KEY WORDS

Radicle Quiescent zone Casparian strip Pneumatiophores
Tap Apical initials Protostele Velamen
Diffuse (fibrous) Protoderm Archs Epiphyte
Feeder roots Ground meristem Hexarch Adventitious
Root cap Provascular tissue Pericycle Excised
Geotropism Endodermis Prop

STUDY QUESTIONS

UNIT 10: ROOTS

1 - Seed structure which forms the primary root

2 - Term for the single, storage root produced by carrot plants

3 - Type of root system characterized by grass plants

4 - Structure which protects the root apex

5 - Root area in region of cell division which has a low rate of mitosis

6 - Root region which is adjacent to the region of cell division

7 - Root region where root hairs occur

8 - Tissue formed from the dicot root ground meristem

9 - Differentiated single cell which functions in absorption

10 - Root layer in the inner area of the cortex

11 - Specialized wall layer associated with the endodermis

12 - Center tissue in primary dicot roots

13 - Center tissues in monocot roots

14 - Tissue which gives rise to the pith in monocot roots

15 - Term for five archs in the primary xylem

16 - Numbers of "patches" of primary phloem in a triarch root

17 - Root layer which gives rise to lateral roots

18 - Root layer which completes the ring of vascular cambium

19 - Root layer which gives rise to the cork cambium

20 - Modified corn roots which function in support

21 - Multiple epidermal layer which functions in absorption in orchid
     modified roots

22 - Specialized root which is formed in symbiotic relationship between
     fungi and dicot roots


LECTURE OUTLINE

UNIT 10: ROOTS

A - Roots - characteristics
   
   1 - Origin - radicle

   2 - Function - absorption, anchor, transport, storage

   3 - Systems - tap, diffuse

   4 - Ability to absorb
       a - location - feeder roots
       b - extent - amount of soil contact

   5 - Anatomy
       a - longitudinal
           (1) root cap - sloughed off, geotropism
           (2) region cell division - active mitosis, quiescent zone,
               root organization, apical initials
           (3) region of elongation - differentiation of protoderm,
               ground meristem, provascular tissue

           (4) region of maturation and root hairs - tissue layers
               (a) epidermis - no cuticle, root hairs
               (b) cortex - storage, plasmodesmata, endodermis - inner
                   layer of cortex, control water movement, Casparian
                   strip - suberin
               (c)vascular tissue - stele 
                        dicots - center xylem in archs
                        with patches phloem
                        monocots - hollow cylinder of vascular tissue
                        with pith in center
                        pericycle - out layer dicot stele, functions - 
                        origin lateral roots, completes vascular cambium,

   6 - Modified roots
       a - prop
       b - pneumatophores
       c - velamen - epiphytes
       d - flower pot plant
       e - food storage - carrot, beet
       f - adventitious roots - cuttings, asexual propagation
       g - mutualistic associations
           (1) mycorrhizae - fungi
           (2) nodules - bacteria

   7 - Excised root cultures - show root
       Growth requires - E source, inorganic nutrients, B vitamins             
          

Return to Bio 205 Main Page