Biology, asked by kanchanapappy2, 7 months ago

how many types of parenchyma are there what are they ​

Answers

Answered by soujanya201074
0

Parenchyma cells can be categorised based on their structure, location and functions performed. The main parenchyma tissues are:

Chlorenchyma: Cells which have chloroplast and perform photosynthesis

The mesophyll cells in leaves which differentiate into palisade and spongy cells

Transfer Cells: They play an important role in the transport of solutes over short distances.

They have cell wall ingrowths, which greatly increase the surface area of the plasma membrane

Sucrose is transported across the membrane through a proton/sucrose co-transport mechanism

These are found in the areas of absorption and secretion in plants like nectaries, salt glands and in carnivorous plants

Vascular Parenchyma: The parenchyma cells which are associated with vascular tissues. These are of two types:

Phloem Parenchyma: It is made up of elongated, tapering and cylindrical cells having dense cytoplasm.

Plasmodesmata connections occur between the cells through pits in the walls

Xylem Parenchyma: It is made up of thin-walled cells. The cell wall is made up of cellulose.

It stores food materials like starch, fats and other substances such as tannins and crystals

Radial conduction of water takes place by ray parenchymatous cells

In the water-stress condition, they help in preventing damage to tracheids and vessels

Storage Parenchyma: These store various substances like water, starch, proteins etc. They act as a food and water reservoir.

Stored protein is a good source of nitrogen for plants

In starch storing cells like in potato tubers, the endosperm of cereals and cotyledons, abundant starch-containing amyloplasts are present

Parenchyma cells may be specialised as a water storage tissue in succulent plants such as Cactaceae, aloe, agave, etc.

In the underground storage like in potato tuber, it can initiate the shoot growth and provide moisture for the initial growth of growing parts

Prosenchyma: These are fibre-like elongated cells, which are thick-walled and provide rigidity and strength to the plant

Aerenchyma: They contain very large intercellular spaces. These are present in aquatic plants.

Aerenchyma helps in the buoyancy of the floating plants

It helps in the respiration and provides sufficient oxygen to the aquatic plants

The aerenchyma formation takes place naturally in the roots of rice (Oryza sativa)

The aerenchyma of leaves and stems of aquatic plants are large longitudinal cells with air spaces or lacunae, which are gas-filled

Aerenchymatous cells are often water-filled

Aerenchyma cells are continuous from shoots to roots and help in diffusion of air from leaves to roots. It helps in maintaining sufficient oxygen levels for respiration.

The excess oxygen consumed, diffuses out from the roots into the soil atmosphere

They help in creating locally aerobic rhizosphere in the anaerobic soil

Epidermis Parenchyma: It is found in the epidermis of the leaves of some gymnosperms.

These have cutinised cell wall

No intercellular spaces

Cutin layer on the outer surface of epidermis reduces transpiration and counters the environmental stress

Have many spiny projections for the protection

Conjunctive Parenchyma: This type of parenchyma is present in the root system.

Non-cutinised, with the thin cell wall, present on the outer layer of the young parts of the root. It is known as epiblema or piliferous layer

It may form tubular outgrowths know as root hair

The main function is to absorb water and minerals from the soil

Functions of Parenchyma cells

Parenchyma cells form the ground tissue of plants. Parenchyma tissues perform various important functions:

Storage: Parenchyma cells have large intercellular space which is ideal for storage

High amount of starch is present in the tubers of potato and cassava

These can store water, fats, oil droplets, and ergastic substances

Store water and act as a water reservoir

Transport: Parenchyma cells transport nutrients and other chemicals

Transfer cells have outgrowth for increasing absorption surface

The xylem parenchyma helps in radial transportation of water and minerals

Some cells transport light from the surface to underground cells

Photosynthesis:

Gas Exchange:

Protection:

Totipotent:

Buoyancy:

Cuticle

Thick-walled parenchyma

Healing and regeneration

Answered by honey971877
1

Answer:

vascular parenchyma, aerenchyma ,cholrenchyma

Explanation:

plant parenchyma is classified into 4 shapes: polyhedral,stellate ,elongated and lobed . in animals, parenchymal cells are the functional cells within the organism. this does not include those that have structural and protective functions like bone cells that makes up a skeleton

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