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Flashcards in Plant tissues Deck (24)
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1

Plant tissues

- continuous, organized masses of similar or varied cells
- A set of cells that functions together

2

Primary growth

growth in length
-rise in primary tissues (herbaceous)

3

Secondary growth

growth in width
-rise in secondary tissue (woody)

4

meristematic tissue

composed of actively dividing undifferentiated cells

5

Meristems that give ride to primary growth:

-apical meristems
-intercalary

6

meristems that give rise to secondary growth are called

lateral meristems
-vascular cambium
-cork cambium

7

apical meristems: shoot meristem

-produce new buds and leaves at terminus and laterally along stems
-form tissues that become the primary structure of stem (epidermis, cortex, primary xylem and phloem, and pith)
-elongation growth
-may develop terminal inflorescences

8

apical meristems: Root meristems

-located at termini of roots
-produce primary root tissues (epidermis, cortex, vascular cylinder)
-Root system growing points
-responsible for elongation growth

9

apical meristems: intercalary meristems

-found mostly in monocots, (esp. grasses)
-located in the lower region of the plant
-near base of plant is why grasses can be mowed

10

Lateral meristems:

-cylinders of actively dividing cells
-results in increase stem girth

11

Vascular cambium

-produces new secondary xylem on the inside, and secondary phloem on the outside

12

cork cambium

produces the periderm (cork)

13

permanent tissue

-composed of non-dividing, differentiated cells
-two types: simple and complex

14

simple permanent tissue

-composed of only one type of cell
-e.g. parenchyma, collenchyma, sclerenchyma

15

complex permanent tissue

-composed of more than one type of cell
-e.g. epidermis, xylem, phloem

16

simple permanent: parenchyma tissue

-alive at maturity
-retain capacity to divide
-usually found just under epidermis
-thin primary cell walls
-cortex= cylindrical zone between the epidermis and phloem
-examples: flesh of potato, lettuce leaf
Functions
-food storage, photosynthesis, wound healing

17

simple permanent: collenchyma tissue

-alive at maturity
-thickened primary cell wall
-occur as long strands on periphery of young stems
functions:
-mechanical support early growth of young stems,
leaf veins, and petioles
-celery strands

18

simple permanent: sclerenchyma tissue

-composed of thick walled cells
-DEAD at maturity
-variable shape
-fibers cause associated with vascular tissue
-common in stems, bark, nut shells, stone cells of pears
Functions:
-conductions, mechanical support, protection

19

complex permanent: epidermis

-single, exterior layer of cells
-includes several cell types: epidermal cells, guard cells
-outside surface usually covered with cutin, a waxy substance that reduces water loss

20

complex permanent: xylem

-structurally complex
-form the yearly growth rings in gymnosperm and woody angiosperms
-non-living when mature
Functions:
-conducts water + dissolved minerals from foots- all plant parts
-structural support

21

complex permanent: phloem

-living when mature
-sieve cells (gymnosperm) or sieve-tube member (angiosperms)
-in woody plants, phloem out word is bark
-primary phloem: produced by apical meristem
-secondary phloem: produced by vascular cambium
Functions:
-conducts food and metabolites from leaves to stem,
flowers, roots and storage organs
-provides structural support

22

dermal system

-layer that envelopes the plant
-protection and gas exchange
-includes: epidermis, Bark, periderm

23

Vascular system

-Xylem and phloem
-conduction and support
-may be ring-like in cross section as with dicots or scattered with monocots

24

fundamental or ground tissue system

-includes all other tissues between the vascular systems and epidermis: cortex, pith, mesophyll
-consists of parenchyma cells, but also includes collenchyma and sclerenchyma
-storage, wound healing, support, and photosynthesis