BIO 2.2 - Plant Cell Types

why is cellular differentiation so important

leads to specialization in structure and function

cell types in plants

Parenchyma

Collenchyma

Sclerenchyma

Water-conducting cells of xylem

Sugar-conducting cells of phloem

when are parenchyma cells alive

living when mature

characteristics of parenchyma cells

thin and flexible 

can divide 

lack secondary cell wall 

large central vacuole 

least specialized cells 

when are collenchyma cells alive

living when mature and can elongate

characteristics of collenchyma cells

not envolved in photosynthesis

thick uneven cell walls 

grouped together in strands 

function of collenchyma cells 

Function is to provide support in elongating parts of the plant without restricting the plants growth 

characteristics of sclerenchyma cells

ridgid cells

mature cells are dead

two types of sclarenchyma cells

sclereids

fibers 

sclereids

thick, lignified walls

fibers

long, slender, arranged in threads 

what tissue are sugar conducting cells part of

phloem tissue

sieve tube elements

alive but lack organelles

what do sieve tube elements allow for

easier transfer of nutrients and connection to other STE to make a long sieve tube 

what are sieve plates

porous end walls that allow fluid to flow between cells along the sieve tubes

companion cell

a cell that accompanies STEs and whoes nucleus and ribosomes serve both cells 

are water conducting cells alive 

dead at maturity 

what are the two types of water conducting cells

tracheids

vessel

tracheids

moves water laterally through pits and tracheids

where are tracheids found

xylem of all vascular plants

vessel

align end to end to form long micropipes called vessels

where are vessels found

common to most angiosperms and few gymnosperms