ROOTS Flashcards
downward growth of the plant into the soil
Root
Functions of roots
- fix the plant to the soil and give mechanical
support to the plant body. - absorb water and the minerals dissolved in
it from the soil and transport them to the aerial parts. - root undergoes modification andper-forms special functions.
Various parts of a root
Root cap
Region of cell division
Region of elongation
Region of root hairs
Region of maturation
protects the growing cells
Root cap
meristematic tissue producing new cells
Region of cell division
increase in the length of the root
Region of elongation
They are responsible for strengthening the hold
of root into the soil and also for the absorption of water.
Region of root hairs
responsible for the absorbed material by roots. The root branches or the lateral roots are produced in this region.
Region of maturation
Types of roots
Tap root system
Adventitious roots
radicle grows into the soil and forms main axis of the root
Tap root system
roots that develop from any part of the plant other than radicle
Adventitious roots.
They store carbohydrates and are used during early growth of successive season.
Modification for storage of food
three types of modifications: Tap roots
Conical
Fusiform
Napiform
These are cone-like, broader at the base and tape-ring at the tip, e.g. carrot.
conical
These roots are more or less spindle shaped, i.e. tapering at both the ends, e.g. radish
Fusiform
These are spherical shaped and very sharply tapering at lower part, e.g. beat and turnip
Napiform
three types of modifications: Adventitious root
Tuberous roots
Fasciculated tuberous roots
Palmated tuberous roots
Annulated roots
Modifications for support
Clinging or Climbing roots
Stilt roots
Columnar roots
These get swollen and form single or isolated tuberous roots which are fusiform in shape, e.g. sweet potato, jalap, aconite.
Tuberous roots
When several tuberous roots occur in a group or cluster at the base of a stem they are termed as fasciculated tuberous roots as in dahlia, asparagus.
Fasciculated tuberous roots
When they are exhibited like palm with fingers as in common ground orchid
Palmated tuberous roots
The swollen portion is in the form of a series of rings called annules as in ipecacuanha.
Annulated roots
These types of roots are developed by plants like black pepper for support or for climbing purposes at nodes.
Clinging or Climbing roots
This type of root is observed in maize and screw-pine, which grow vertically or obliquely downwards and penetrate into soil and give addi-tional support to the main plant.
Stilt roots
In certain plants like banyan, the additional support is given by specially developed pillars or columnar roots
Columnar roots
Modifications for special functions:
Respiratory roots or pneumatophores
Sucking roots or Haustoria
Photosynthetic root
Epiphytic or Assimilatory roots
Nodulated roots or root tubercles
Epiphytic or Assimilatory roots consist of
Clinging roots
Aerial roots
The roots of the plant growing in marshy places on sea-shores due to continuous water logging are unable to respire properly.
Respiratory roots or pneumatophores
These roots neither possess root caps nor root hairs
Sucking roots or Haustoria
become green in colour on exposure to sunlight and perform photosynthesis
hotosynthetic roots
plants which grow on the branches or stems of the plants without taking any food from them
Epiphytic or Assimilatory roots
which they get fixed with the host and
Clinging roots
hich hang freely in the air, These roots are devoid of root caps and root hairs. They carry on photosynthesis
Aerial roots
These are formed by nitrogen fixing bacteria
and getting carbohydrates from the plants.
Nodulated roots or root tubercles
Uses of roots
Source of food and vegetables
Various types of medicinally important drugs are
obtained from root.
