BIOG162 - Modules 25-26 Plant Tissues

Covers meristem, ground, dermal, and vascular tissues.

meristem, ground, dermal, vascular

major plant tissue types

meristem tissue

where cell division and growth occurs, cells are unspecialized

proplastids

unspecialized plastids that will eventually become specialized

primary growth

vertical growth at the tips of the roots and shoot

apical meristems

the location of primary growth, another term for the tips

mature ground meristem becomes…

ground tissue

mature protoderm becomes…

dermal tissue

mature procambium becomes…

vascular tissue

what determines primary meristems?

the location

primary meristems

mature meristems that become another tissue type

initials

remain as apical meristems

derivatives

turn into primary meristems

secondary growth

increase the width

cambia

cylindrical meristem, allows for the width to increase

what plant types do not have cambia?

monocots

initials and derivatives

formed by the division of an apical meristem

quiescent center

the middle of the meristem

intercalary meristem

meristem sandwiched between specialized tissues, allows for quick growth

ground tissue

the main functions are metabolism, storage, and support

parenchyma, collenchyma, sclerenchyma

main types of ground tissue

parenchyma

living cells with a thin primary cell wall, are responsible for metabolism and storage, are the most abundant and are water permeable

chlorenochyma

a photosynthetic parenchyma

collenchyma

living cells with unevenly thickened primary cell walls, are responsible for supporting the veins and growing regions

sclerenchyma

dead cells with a thick secondary cell wall, do not let water in, provide a very rigid form of support

sclereids and fibers

sclerenchyma subtypes

sclereids identifying characteristics

short and squat

fibers identifying characteristics

long and slender

apical and primary

types of meristem tissue

dermal tissue

form the outer protective coverings on a plant

epidermal tissue

single layer of epidermal cells, are tightly packed together and transparent, create the waxy cuticle

cutin

make up the cuticle

why is the epidermal tissue transparent?

allow light to enter the plant for photosynthesis

trichomes

extensions off of epidermal cells, have many different possible functions, not all epidermal cells have them

guard cells

regulate the stomata’s pore size via changes in turgor pressure

periderm

the dermal tissue present in wooden plants, made of dead layers of cork cells with suberin

vascular tissue

conduct fluids throughout the plant’s body

xylem and phloem

vascular tissue types

xylem

mostly transports water and inorganic nutrients, dead with lignified secondary cell walls

tracheids

long and thin, have pits to transport water, present in xylem, found in all vascular plants

vessel elements

wide and short, have both pits and perforations, present in xylem

pits

gaps in the secondary cell wall

perforation

gaps in both the primary and secondary cell wall

where are vessel elements found?

angiosperms and gnetophytes

phloem

transport dissolved glucose and other organic materials, cells are living

sieve-tube members

transport pipes with sieve plates to control the sap flow, connect to a companion cell, present in phloem

companion cell

connect to sieve-tubes in phloem, house shared organs between itself and a sieve-tube, connect via plasmodesmata, responsible for loading/unloading

source tissues

where carbohydrate export occurs in phloem

sink tissues

where carbohydrate import occurs in phloem

directional flow in phloem

from source to sink; several directions