Changes

= Concept Map =

= Concept Map =

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<mm>[[Plant tissues.mm|Flash]]</mm>

[[File:Plant tissues.mm|Flash]]

= Textbook =

= Textbook =

==Useful websites==

==Useful websites==

==Reference Books==

==Reference Books==

 

= Teaching Outlines =

= Teaching Outlines =

===Notes for teachers===

===Notes for teachers===

The growth of plants occurs only in certain specific regions. This is because the dividing tissue, also known as meristematic tissue, is located only at these points. Depending on the region where they are present,meristematic tissues are classified as apical,lateral and intercalary. New cells produced by meristem are initially like those of meristem itself, but as they grow and mature, their characteristics slowly change and they become diferentiated as components of other tissues.  

The growth of plants occurs only in certain specific regions. This is because the dividing tissue, also known as '''meristematic tissue''', is located only at these points. Depending on the region where they are present,meristematic tissues are classified as '''apical,lateral and intercalary'''. New cells produced by meristem are initially like those of meristem itself, but as they grow and mature, their characteristics slowly change and they become diferentiated as components of other tissues.  

http://media-3.web.britannica.com/eb-media/99/5599-004-D6C19960.gif

[[File:meristematic_tissue.gif|400px]]

Apical meristem is present at the growingtips of stems and roots and increases thelength of the stem and the root. The girth ofthe stem or root increases due to lateral meristem (cambium). Intercalary meristem is the meristem at the base of the leaves or internodes (on either side of the node) or twigs.<br>

 

'''Apical meristem''' is present at the growingtips of stems and roots and increases thelength of the stem and the root. The girth ofthe stem or root increases due to '''lateral meristem (cambium)'''. '''Intercalary meristem''' is the meristem at the base of the leaves or internodes (on either side of the node) or twigs.<br>

Cells of the  meristematic tissues show the following features:

Cells of the  meristematic tissues show the following features:

* The cells have thin walls.

* The cells have thin walls.

===Activities===

===Activities===

#Activity No #1 [[Plant_tissues_Meristematic_tissue_activity1]]

#Activity No #1 [[Plant_tissues_Meristematic_tissue_activity1]]

#Activity No #2 '''page_name_concept_name_activity2'''

#Activity No #2 ''concept_name_Activity_no''

==Concept #2-Permanent tissues-Simple permanent tissues==

==Concept #2-Permanent tissues-Simple permanent tissues==

Cells formed by meristematic tissue take up a specific role and lose the ability to divide. As a result,they form a permanent tissue. This processof taking up a permanent shape,size and function is called differentiation. Cells of meristematic tissue differentiate to form different types of permanent tissue.<br>

Cells formed by meristematic tissue take up a specific role and lose the ability to divide. As a result,they form a permanent tissue. This processof taking up a permanent shape,size and function is called differentiation. Cells of meristematic tissue differentiate to form different types of permanent tissue.<br>

Parenchyma, in plants, tissue typically composed of living cells that are thin-walled, unspecialized in structure, and therefore adaptable, with differentiation, to various functions. Parenchyma may be compact or have extensive spaces between the cells. It is often called ground, or fundamental, tissue and makes up the mesophyll (internal layers) of leaves and the cortex (outer layers) and pith (innermost layers) of stems and roots; it also forms the soft tissues of fruits. Cells of this type are also contained in xylem and phloem as transfer cells and, with both xylem and phloem as bundle sheaths, the cells that surround the vascular strands.<br>

Parenchyma, in plants, tissue typically composed of living cells that are thin-walled, unspecialized in structure, and therefore adaptable, with differentiation, to various functions. Parenchyma may be compact or have extensive spaces between the cells. It is often called ground, or fundamental, tissue and makes up the mesophyll (internal layers) of leaves and the cortex (outer layers) and pith (innermost layers) of stems and roots; it also forms the soft tissues of fruits. Cells of this type are also contained in xylem and phloem as transfer cells and, with both xylem and phloem as bundle sheaths, the cells that surround the vascular strands.<br>

 

[[File:parenchyma.jpg|250px]]

http://www.mhhe.com/biosci/pae/botany/histology/images/parench.jpg

'''Parenchyma tissue'''

'''Parenchyma tissue'''

The flexibility in plants is due to another permanent tissue, collenchyma. It allows easy bending in various parts of a plant (leaf,stem,petiole) without breaking. It also provides mechanical support to plants. We can find this tissue in leaf stalks below the epidermis.The cells of this tissue are living, elongated and irregularly thickened at the corners. There is very little intercellular space.The cell wall is made up of cellulose and pectin.<br>

The flexibility in plants is due to another permanent tissue, collenchyma. It allows easy bending in various parts of a plant (leaf,stem,petiole) without breaking. It also provides mechanical support to plants. We can find this tissue in leaf stalks below the epidermis.The cells of this tissue are living, elongated and irregularly thickened at the corners. There is very little intercellular space.The cell wall is made up of cellulose and pectin.<br>

http://everythingscience.co.za/lifesciences/grade-10/04-plant-and-animal-tissues/images/6d29e2ef912af90a6d0451f417787577.png<br>

[[File:collenchyma1.jpeg|300px]]

 

[[File:collenchyma.jpg|300px]]

http://images.tutorvista.com/content/tissues-plants-animals/collenchyma-cells.jpeg

'''SCLERENCHYMA''':<br>

'''SCLERENCHYMA''':<br>

'''Sclerieds''' are hard cells having more lignin.Hence they are commonly called '''stone cells'''.They are generally found in fruit wall and seed coats.

'''Sclerieds''' are hard cells having more lignin.Hence they are commonly called '''stone cells'''.They are generally found in fruit wall and seed coats.

http://www.transtutors.com/Uploadfile/CMS_Images/2871_Sclerenchymatous.JPG

[[File:Sclerenchyma.JPG|350px]]

http://www.tantebazar.com/imgx/simple_plant_tissues.jpg

[[File:simple_plant_tissues.jpg|350px]]

DERMAL TISSUE:<br>

The outermost covering of all parts of plant-stem,leaves,flowers,fruits,seeds and roots- is formed by protective tissue called Dermal tissue.The epidermis is usually made of a single layer of cells. In some plants living in very dry habitats, the epidermis may be thicker since protection against water loss is critical. The entire surface of a plant has this outer covering of epidermis. It protects all the parts of the plant.Epidermal cells on the aerial parts of the plant often secrete a waxy, water-resistant layer on their outer surface. This aids in protection against loss of water, mechanical injury and invasion by parasitic fungi.<br>

 

We can observe small pores here and there in the epidermis of the leaf. These pores are called stomata. Stomata are enclosed by two kidney-shaped cells called guard cells. They are necessary for exchanging gases with the atmosphere.Transpiration (loss of water in the form of water vapour) also takes place through stomata.<br>

'''DERMAL TISSUE''':<br>

The outermost covering of all parts of plant-stem,leaves,flowers,fruits,seeds and roots- is formed by protective tissue called '''Dermal tissue'''.The epidermis is usually made of a single layer of cells. In some plants living in very dry habitats, the epidermis may be thicker since protection against water loss is critical. The entire surface of a plant has this outer covering of epidermis. It protects all the parts of the plant.Epidermal cells on the aerial parts of the plant often secrete a waxy, water-resistant layer cutin on their outer surface. This aids in protection against loss of water, mechanical injury and invasion by parasitic fungi.<br>

We can observe small pores here and there in the epidermis of the leaf. These pores are called '''stomata'''. Stomata are enclosed by two kidney-shaped cells called guard cells. They are necessary for exchanging gases with the atmosphere.Transpiration (loss of water in the form of water vapour) also takes place through stomata.<br>

Epidermal cells of the roots, whose function is water absorption, commonly bear long hair-like parts that greatly increase the total absorptive surface area.<br>

Epidermal cells of the roots, whose function is water absorption, commonly bear long hair-like parts that greatly increase the total absorptive surface area.<br>

In some plants like desert plants,cabbage,banana etc. epidermis has a thick waxy coating of cutin on its outer surface to prevent water loss.<br>

In some plants like desert plants,cabbage,banana etc. epidermis has a thick waxy coating of '''cutin''' on its outer surface to prevent water loss.<br>

 

http://www.bbc.co.uk/schools/gcsebitesize/science/images/bi05004.gif<br>

Cross section of a leaf showing epidermis

'''Cross section of a leaf showing epidermis'''

===Activities===

===Activities===

The xylem parenchyma stores food and helps in the sideways conduction of water.Xylem fibres are mainly supportive in function.<br>

The xylem parenchyma stores food and helps in the sideways conduction of water.Xylem fibres are mainly supportive in function.<br>

http://www.dr-evans.com/advancedbiology/images/xylemstructure.jpg<br>

[[File:xylemstructure.jpg|400px]]

'''PHLOEM'''<br>

'''PHLOEM'''<br>

There are certain cells closely associated with sieve tube,called '''companion cells'''.They regulate the passage of food through sieve tubes. Except for phloem fibres, phloem cells are living cells.<br>

There are certain cells closely associated with sieve tube,called '''companion cells'''.They regulate the passage of food through sieve tubes. Except for phloem fibres, phloem cells are living cells.<br>

http://www.bbc.co.uk/bitesize/standard/biology/images/structure_phloem.gif

[[File:structure_phloem.gif|300px]]

'''Phloem'''

'''Phloem tissue'''

http://www.infovisual.info/01/img_en/014%20Cross%20section%20of%20a%20stem.jpg

[[File:corn_stem_zea_section.jpg|350px]]

'''Figure showing arrangement of vascular bundles in a stem'''

'''Figure showing arrangement of vascular bundles in a corn stem'''

===Activities===

===Activities===

#Activity No #1 '''page_name_concept_name_activity1'''

#Activity No #1[[Complex_permanent_tissue]]

#Activity No #2 '''page_name_concept_name_activity2'''

#Activity No #2[[xylem_tissue]]

==Concept #4==

==Concept #4==