Lab 6. TISSUES- a group of cells functioning together in some specialized activity

Plant tissues

Lab 6

102 Bot

TISSUES- a group of cells functioning together in some specialized activity

Tissues

Plant Tissues Types

All plant organs (roots, stems, leaves) are composed of the same tissue types.

Classification of Plant Tissues

PARENCHYMA - البرانشيمية األنسجة

COLLENCHYMA - الكولنشيمية األنسجة

SCLERENCHYMA - السكالرنشيمية األنسجة

XYLEM الخشب

PHLOEM اللحاء

Plant Cell and Tissue Types

2 .Permanent or mature tissue1 .Meristematic tissue

Meristematic tissue

Meristematic tissueShoot

Root

2 .Permanent or mature tissue

PARENCHYMACharacteristics

least specialized cell typeonly thin primary cell wall is presentpossess large central vacuolegenerally alive at functional maturityThis tissue is found in the soft parts of the plant like the cortex(outer region) and pith (inner region) of the roots and stems.

Functionsmake up most of the ground tissues of the plantstoragephotosynthesiscan help repair and replace damaged organs by proliferation and specialization into other cells

Equal diameters parenchyma

Parenchyma

Ribbed

aerenchyma

Parenchyma

Chlorenchyma

Water storage parenchymafood storage parenchyma

CollenchymaCharacteristics

possess thicker primary cell walls the that of parenchymano secondary cell wall presentgenerally alive at functional maturity

Functionsprovide support without restraining growth

Types of collenchyma

Angular collenchyma- 1زاوي

Lamellar (lamellate) collenchyma- 2صفائحي

Lacunar (lacunate)- 3 فراغيcollenchyma

SclerenchymaCharacteristicshave secondary cell walls strengthened by ligninoften are dead at functional maturitytwo forms: fibers and sclereidsFunctionsrigid cells providing support and strength to tissues

Sclerenchyma

1 -fiber 2-sclereids -stone cells

1-Fibres

2-Sclereids

bone shapedstar shapedoval in shape

عصوية حجرية خالياBacillary

C o m p l e x P e r m a n e n t T i s s u e s

Xylem and Phloem

Xylem

They are four basic elements in Xylem :

Xylem tracheids

Xylem tracheae or vessels

Xylem fibers

Xylem parenchyma

الخشب في التغلظات أنواعحلزوني

Spiral حلقيannular

منقرpitted

شبكيreticulate

Phloem is a heterogenous tissue, made up of four different types of cellular elements, namely,

Sieve tubes

Companion cells

Phloem parenchyma

Phloem fibres

Phloem

Phloem parenchyma

Munira Al-Dosari