Nastic and epinastic responses, Biology

Assignment Help:

Nastic and Epinastic Responses

Paratonic variation movements of plant parts in which direction of movement is independent of the direction of stimulus. Nastic responses are like closing of leaflets by touch (E.g. Mimosa pudica) and Epinastic responses are like bending downward of the petiole bringing the leaf to a hanging position. Ethylene causes epinasty of leaves by promoting elongation of cells on the upper side. If one half of a leaf of plant like xanthium is shaded, then the corresponding site of the petiole elongation so that the petiole bends displacing the leaf blade towards irradiated side. Secondly upward bending of the shaded side of the leaf (hyponasty) this mechanism helps the plant in avoiding overlapping of leaves and maximum exposure to Light. The canoppy forms leaf mosaics.


Related Discussions:- Nastic and epinastic responses

What do you mean by cold deserts, What do you mean by Cold Deserts? Col...

What do you mean by Cold Deserts? Cold deserts cover a vast area north of the Himalayan ranges forming an ecosystem with exceptionally low temperatures which may reach - 75°C a

Define the nutritional needs of microorganisms, Define the Nutritional Need...

Define the Nutritional Needs of Microorganisms? About 95% of dry cell weight of microorganisms is constituted by macro elements. These are carbon (C), nitrogen (N), oxygen (O),

Explain what is probing depth, Q. Explain What is Probing Depth? This p...

Q. Explain What is Probing Depth? This parameter is applicable to one stage implants when they are evaluated prior to prosthetic phase and used to evaluate the health of the im

What is weaning from mechanical ventilation, What is Weaning from Mechanica...

What is Weaning from Mechanical Ventilation? It is crucial to get the timing just right as to when to discontinue mechanical ventilation and extubate. If too early, this might

Which is most likely be fatal to marin fish populations, If we were to comp...

If we were to completely eliminate one group of marine organisms from ocean, which would most likely be fatal to Marin fish populations? Elimination of: a) Starfishes b) Dia

Lamellar models, LAMELLA R MODELS According to James Danielly & Hu...

LAMELLA R MODELS According to James Danielly & Hugh Davson (1935) cell membrane consists of 4 layers P-L-L-P. Molecules of phospholipid has amphipathic nature, i.e. it

Cell theory, why is virus an exception of cell theory

why is virus an exception of cell theory

Explain the acquired deficiency of the vitamin k metabolism, Why are some t...

Why are some types of hemorrhagic diseases caused by genetic or acquired deficiency of the vitamin K metabolism? Lack of vitamin K predisposes to hemorrhages as this vitamin i

Determine nutritional requirements in hot environments, Determine Nutrition...

Determine Nutritional Requirements in Hot Environments? Hot environments may be of two types: dry hot, as in the case of deserts or hot and humid in tropical rain forests and c

Tolerance range, Maximum and minimum range of an animal with the factors of...

Maximum and minimum range of an animal with the factors of Ph Salinity Pressure Relative human

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd