exam 1 slides 7 and 8

Question 1

Meristems

Answer 1

Actively dividing cells or cells that
retain the ability to divide

Question 2

Cells in meristems

“anatomy”

Answer 2

-primary walls only (no secondary walls)
–lack a large central vacuole
»small vacuoles instead

Question 3

Apical meristem at
stem tip

function of it

Answer 3

– Contributes to increase
in stem length
– Dormant before growing
season begins
– Protected by bud scales
and by leaf primordia
-Leaf primordia

Question 4

Leaf primordia

Answer 4

Tiny
embryonic leaves that develop
into mature leaves

Question 5

Apical Meristems

Answer 5

-Found at the tips of roots and shoots
* Roots and shoots increase in length as the apical meristems
produce new cells

Question 6

Roots and shoots increase in length as the apical meristems
produce new cells

Answer 6

primary growth

Question 7

Apical meristems give rise to 3 primary meristems that also
cause primary growth and produce primary tissues

Answer 7

-Protoderm
* Ground meristem
* Procambium

Question 8

Protoderm - Gives rise to

Answer 8

epidermis

Question 9

Procambium - Produces

Answer 9

primary xylem and phloem

Question 10

Ground Meristem -
Produces

Answer 10

pith and cortex,
both composed of
parenchyma cells
(produces fundamental or
ground tissue in monocot
stem)

Question 11

Lateral Meristems =

Answer 11

Secondary Meristems

• Produce secondary tissues that increase the girth of
  roots and stems (= secondary growth)
• For thickening growth
• Include the vascular cambium and the cork cambium.
• Found in dicots and gymnosperms
• Monocots lack typical secondary growth

Question 12

Vascular Cambium

Answer 12

– A secondary meristem
– Composed of a thin cylinder of brick-shaped cells
that extends the length of stems and roots
– Causes thickening growth
– Produces secondary xylem and secondary phloem
– Forms true wood

Question 13

Cork Cambium =

Answer 13

=Phellogen
– A secondary or lateral meristem.
– A thin cylinder that runs the length of roots and
stems of woody plants
– Is to the outside of the vascular cambium
within the outer bark (periderm)
* Produces secondary tissues:
– Produces cork to the outside
– Produces phelloderm to the inside

Question 14

Intercalary Meristems

Answer 14

• Grasses and related plants do not have a vascular
  cambium or a cork cambium.
• They have apical meristems.
• Intercalary meristems are present.
• Occur in vicinity of nodes (leaf attachment area)
  along stems
• Add to stem length
• When you cut the grass the intercalary meristems
  remain to regrow the grass.

Question 15

Tissues Produced by Meristems

(what do they look like)

Answer 15

-After they arise from the meristems, maturing cells
assume various shapes and sizes.
* Shape is related to function.
* Simple tissues and complex tissues are produced

Question 16

Fibrous root system what type of stem

Answer 16

typical monocot

Question 17

what type of stem have taproots

Answer 17

typical dicot

Question 18

Root cap

Answer 18

• The root cap protects the sensitive apical
  meristem as the root grows through the soil.
• It secretes a slimy sheath to help the root
  grow through the soil.
• It is the site of gravity perception.

Question 19

Region of Cell Division composed of

Answer 19

apical meristem in
the center of root tip

Question 20

Root apical meristem gives rise
to 3 primary meristems

Answer 20

Protoderm
ground meristem
procambium

Question 21

Protoderm gives rise to

Answer 21

epidermis

Question 22

Ground meristem - Gives rise to

Answer 22

cortex and pith (if present

Question 23

procambium gives rise to

Answer 23

primary
xylem and primary phloem

Question 24

Region of Elongation

Answer 24

Cells become several times their
original length

Question 25

how does The Region of Elongation work

Answer 25

– Vacuoles merge
– No further increase in cell size takes place above the
region of elongation.
– Increases in girth may occur if vascular cambium is
present

Question 26

The Region of Maturation

Answer 26

• Sometimes called the root hair zone
  – Root hairs are extensions of epidermal cells
• Cells differentiate and tissues form

Question 27

Casparian Strips

Answer 27

• Named after Robert Caspary
• Consist of fatty suberin
• Impermeable to water
• Found on 4 out of the 6 walls of endodermis
  cells
  – Passage cells do not have Casparian strips
• Force water and dissolved substances through
  selectively permeable plasma membranes
• Enable control over what enters the vascular
  transport system within the vascular cylinder

Question 28

Typical Dicot Root

things in it

Answer 28

• Epidermis
• Cortex
• Vascular cylinder
• No pith, just cortex
• Secondary growth occurs in some species

Question 29

epidermis in Typical Dicot Root

Answer 29

-Site of root hair origin

Question 30

Cortex in typical dicot root

Answer 30

– Parenchyma cells between epidermis and vascular
cylinder
– Main function is storage
– Endodermis with Casparian strips is inner
boundary between cortex and vascular cylinder

Question 31

Vascular cylinder (stele) in the center of root in typical dicot root

Answer 31

– Surrounded by endodermis with Casparian Strips
– Pericycle site of origin of branch roots
– Solid core of xylem with “arms”
– Phloem in between “arms” of xylem

Question 32

Secondary growth occurs in some species in a typical dicot root

Answer 32

Wood formation and bark formation

Question 33

Typical Monocot Root

Answer 33

• Has epidermis with root hairs
• Has pith and cortex
• Has endodermis with Casparian strips
• Has pericycle beneath endodermis
  – Site of origin of lateral (branch) roots
• Xylem alternates with phloem in a circle
  (cylinder) surrounding the pith
• No secondary growth

Question 34

Monocot roots
summary

Answer 34

• Pith and cortex

Question 35

Dicot roots summary

Answer 35

Cortex, no pith

Question 36

Monocot shoots summary

Answer 36

Fundamental tissue
(ground tissue)

Question 37

Dicot shoots summary

Answer 37

Pith and cortex

Question 38

Specialized Roots: used for

Answer 38

1. Food storage
2. water storage
   3.propagative roots
   4.pneumatophores
   5.aerial roots
3. parasitic roots
   7.mycorrhizae
   8.root nodules

Question 39

food storage

Answer 39

A combination of root and stem:
– Carrots
– Beets
– Turnips
– Radishes

Question 40

3. Propagative Roots

Answer 40

• Buds on roots develop into suckers (aerial
  stems)
• Some plants can spread this way
  – Fruit trees
• Cherries, apples, pears
  – Some invasives
• Canada thistle
• Tree-of-heaven

Question 41

Invasive Canada Thistle, Invasive Tree of Heaven with Propagative Roots

Answer 41

• Not from Canada, not native to N. America
• Can extend up to 15 feet by propagative roots

Question 42

4. Pneumatophores

Answer 42

• In some species with
  roots growing in water
• Spongy roots that
  extend above the
  water’s surface and
  enhance gas exchange
  between atmosphere
  and subsurface roots
• Found in mangroves

Question 43

5. Aerial Roots

Answer 43

• Corn prop roots
• Orchid velamen roots
  -banyan trees

Question 44

6. Parasitic Roots

Answer 44

• Dodder plant with haustoria
  – Haustoria tap into host to absorb water and nutrients

-Mistletoe (partial parasite) has haustoria to
absorb water and minerals