What is a plant tissue
Dear student,
Plant tissues Multi cellular organisms are made of millions of cells. cells are structural and functional unit of life. They show division of labour and each cell perform a particular function efficiently.Such cells are grouped together and are called as tissues. In other words Tissue is a group of cells which are similar in structure and origin and perform similar function.
In plants,most of the tissue is dead and provide mechanical strength to plants. Plant tissues are of two types.
- Meristematic tissue
- Permanent tissue
MERISTEMATIC TISSUE The cells of this tissue have the ability to divide and redivide to form new cells. The newly formed cells are similar to the parent cells but as they grow their characteristic change and they differentiate. These cells help in increase of length and girth(width) of plants and are found in growing areas of plants. This cells are living, have dense cytoplasm, thin cellulose walls,prominent nuclei and lack vacuole as vacuole provide rigidity to cells preventing quick division.
TYPES OF MERISTEMATIC TISSUE. 1. APICAL MERISTEM LOCATION- This type of meristem is found at growing tips of stem and root.
FUNCTION-This tissue help in increase in length of the plant.
2.LATERAL MERISTEM LOCATION- This type of meristem is found on sides of stem and root.
FUNCTION- This tissue help in increase the diameter and girth of plant.
3. INTERCALARY MERISTEM LOCATION- This type of tissue is found at the base of leaves or internodes.
FUNCTION-This tissue help in increase the length of organs like leaves and internodes.
PERMANENT TISSUE These are the tissues that come from meristematic tissue and are matured. The meristematic cells form permanent tissue once they loose the ability to divide. This cells have definite shape,size and function and may be dead or living. The process by which cells arise from meristematic tissue and take up a permanent shape,size and function is called
Permanent tissues differentiation. Permanent tissues are of two types,
- Simple permanent tissue.
- Complex permanent tissue.
SIMPLE PERMANENT TISSUE This type of tissue are made of one type of cells. Simple permanent tissues are of three types,
- Parenchyma
- Collenchyma
- Sclerenchyma
PARENCHYMA CHARACTERISTICS- it is the basic packaging tissue that fills the spaces between other tissues and is found most abundantly in plants.They have unspecialised/ undifferentiated cells with thin cell walls made of cellulose. they have large intercellular spaces as the cells are loosely packed. Cells have dense cytoplasm and nucleus and large vacuole.
FUNCTION- This tissue provide support to plants and parenchyma of stem and roots stores nutrients and water and is called as STORAGE PARENCHYMA. when it contains chloroplast having chlorophyll and performs photosynthesis, it is called CHLORENCHYMA. In aquatic plants, parenchyma has large air spaces to provide buoyancy to plants to help them float and exchangegases, it is called PARENCHYMA.
LOCATION- This type of tissue found in non woody or soft parts of roots,stem,flowers,leaves and fruits.
COLLENCHYMA CHARACTERISTICS- The cells are living, elongated and irregularly thick at the corners made of cellulose or pectin they have very less of no intercellular spaces. The cells have a nucleus, dense cytoplasm and Large vacuole.
FUNCTIONS- These cells provide flexibility (elasticity) and mechanical support to the aerial parts of the plants and allows them to bend.
LOCATION- This type of tissue is found in leaf stalks, below epidermis of leaves and stem.
SCLERENCHYMA CHARACTERISTICS- The cells are long, narrow thick walled due to deposition of lignin. Such cell walls are called as lignified walls and have pits. These cells lack intercellular spaces due to deposition of lignin. The cells do not have a nucleus and cytoplasm and are dead.
FUNCTIONS -These cells provide rigidity and strength to plants and makes it hard and can bear stess and strains.
LOCATION- This type of cells are found in stems,around vascular bundles,in the veins of leaves.
COMPLEX PERMANENT TISSUE This type of tissue is made up of more than one type of cells that have a common origin and work together to do a common function. Its function is to transport water,minerals and food to all parts of the plant. Complex permanent tissue is of two types,
- XYLEM
- PHLOEM
1. XYLEM The cells have thick walls.Elements are tracheids,vessels,xylem parenchyma,and xylem sclerenchyma. Vessels are the most important elements and are shorter and wider than tracheids. Vessels and tracheids have tube like structures that help in transporting water and minerals vertically efficiently. Conduction takes place in one direction. Xylem parenchyma stores food and helps in lateral conduction of water. In addition to transporting water and mineral salts from roots to leaves, xylem also provides support to plants and trees because of its tough lignified vessels. In xylem, only the Xylem parenchyma is living and all other elements are dead.
Bigger pink cells - Old xylem(meta xylem) Small pink cells - new xylem(proto xylem) 2.PHLOEM Elements of phloem are seive tubes,companion cells,phloem parenchyma and phloem fibres. Seive tubes are tube like structures, The end walls are called seive plates and are perforated due to presence of pores. Phloem transports the prepared food from leaves to storage organ and from storage organ to growing regions. Hence the conduction is bi directional.In phloem all the elements are living except the phloem fibres.
phloem
Hope it helps
Best wishes!
Dear student,
Plant tissues
Multi cellular organisms are made of millions of cells. cells are structural and functional unit of life. They show division of labour and each cell perform a particular function efficiently.Such cells are grouped together and are called as tissues. In other words Tissue is a group of cells which are similar in structure and origin and perform similar function.
In plants,most of the tissue is dead and provide mechanical strength to plants. Plant tissues are of two types.
- Meristematic tissue
- Permanent tissue
The cells of this tissue have the ability to divide and redivide to form new cells. The newly formed cells are similar to the parent cells but as they grow their characteristic change and they differentiate. These cells help in increase of length and girth(width) of plants and are found in growing areas of plants. This cells are living, have dense cytoplasm, thin cellulose walls,prominent nuclei and lack vacuole as vacuole provide rigidity to cells preventing quick division.
TYPES OF MERISTEMATIC TISSUE. 1. APICAL MERISTEMLOCATION- This type of meristem is found at growing tips of stem and root.
FUNCTION-This tissue help in increase in length of the plant.
2.LATERAL MERISTEMLOCATION- This type of meristem is found on sides of stem and root.
FUNCTION- This tissue help in increase the diameter and girth of plant.
3. INTERCALARY MERISTEMLOCATION- This type of tissue is found at the base of leaves or internodes.
FUNCTION-This tissue help in increase the length of organs like leaves and internodes.
PERMANENT TISSUEThese are the tissues that come from meristematic tissue and are matured. The meristematic cells form permanent tissue once they loose the ability to divide. This cells have definite shape,size and function and may be dead or living. The process by which cells arise from meristematic tissue and take up a permanent shape,size and function is called
Permanent tissues
differentiation. Permanent tissues are of two types,
- Simple permanent tissue.
- Complex permanent tissue.
This type of tissue are made of one type of cells. Simple permanent tissues are of three types,
- Parenchyma
- Collenchyma
- Sclerenchyma
CHARACTERISTICS- it is the basic packaging tissue that fills the spaces between other tissues and is found most abundantly in plants.They have unspecialised/ undifferentiated cells with thin cell walls made of cellulose. they have large intercellular spaces as the cells are loosely packed. Cells have dense cytoplasm and nucleus and large vacuole.
FUNCTION- This tissue provide support to plants and parenchyma of stem and roots stores nutrients and water and is called as STORAGE PARENCHYMA. when it contains chloroplast having chlorophyll and performs photosynthesis, it is called CHLORENCHYMA. In aquatic plants, parenchyma has large air spaces to provide buoyancy to plants to help them float and exchangegases, it is called PARENCHYMA.
LOCATION- This type of tissue found in non woody or soft parts of roots,stem,flowers,leaves and fruits.
COLLENCHYMACHARACTERISTICS- The cells are living, elongated and irregularly thick at the corners made of cellulose or pectin they have very less of no intercellular spaces. The cells have a nucleus, dense cytoplasm and Large vacuole.
FUNCTIONS- These cells provide flexibility (elasticity) and mechanical support to the aerial parts of the plants and allows them to bend.
LOCATION- This type of tissue is found in leaf stalks, below epidermis of leaves and stem.
SCLERENCHYMACHARACTERISTICS- The cells are long, narrow thick walled due to deposition of lignin. Such cell walls are called as lignified walls and have pits. These cells lack intercellular spaces due to deposition of lignin. The cells do not have a nucleus and cytoplasm and are dead.
FUNCTIONS -These cells provide rigidity and strength to plants and makes it hard and can bear stess and strains.
LOCATION- This type of cells are found in stems,around vascular bundles,in the veins of leaves.
COMPLEX PERMANENT TISSUEThis type of tissue is made up of more than one type of cells that have a common origin and work together to do a common function. Its function is to transport water,minerals and food to all parts of the plant. Complex permanent tissue is of two types,
- XYLEM
- PHLOEM
The cells have thick walls.Elements are tracheids,vessels,xylem parenchyma,and xylem sclerenchyma. Vessels are the most important elements and are shorter and wider than tracheids. Vessels and tracheids have tube like structures that help in transporting water and minerals vertically efficiently. Conduction takes place in one direction. Xylem parenchyma stores food and helps in lateral conduction of water. In addition to transporting water and mineral salts from roots to leaves, xylem also provides support to plants and trees because of its tough lignified vessels. In xylem, only the Xylem parenchyma is living and all other elements are dead.
Bigger pink cells - Old xylem(meta xylem) Small pink cells - new xylem(proto xylem) 2.PHLOEM
Elements of phloem are seive tubes,companion cells,phloem parenchyma and phloem fibres. Seive tubes are tube like structures, The end walls are called seive plates and are perforated due to presence of pores. Phloem transports the prepared food from leaves to storage organ and from storage organ to growing regions. Hence the conduction is bi directional.In phloem all the elements are living except the phloem fibres.
phloem
Hope it helps
Best wishes!
