Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Types of xerophytes
On the basis of their mbrphology, physiology and life cycle pattern, xerophytes are generally classified into the following three categories:
a) Ephemeral annuals also called drought evaders or drought escapers are common in arid zones. These annuals are able to complete their life cycle within a short period of 6-8 weeks during which moisture conditions are favourable. As the moisture gets depleted these annuals dry out leaving behind a crop of seeds to tide over the adverse dry period. They actually avoid the dry period and form seeds which are highly resistant to aridity. Argemone mexicana, Solanurn xanthouupum and Cassia tom are good examples of drought escapers.
b) Succulents: Plants adapted to hot and dry areas are called succulents. They have fleshy stem, leaves and roots which are swollen and serve as water storage organs. These plants are able to accumulate large amounts of water during the brief rainy season. To minimise water loss from the plants leaves either become very small or modify into thorns or are absent altogether to cut down water loss through transpiration. The root system is shallow, with wide horizontally spread stem and leaves are thick, swollen and leathery. Examples of succulents are Opuntia sp., Euphorbia splendens and various types of cacti, and Agave. In many cases stems become succulent as in Opuntia and Eupborbia splendens. They are also called fleshy xerophytes. In such xerophytes, cuticle is thick with a well developed two to three layered hypodermis.
c) Non-succulent perennials: These are actually the true xerophytes or drought resistants, because they possess a number of morphological, anatomical and physiological characteristics which enable them to withstand critical dry conditions. They exhibit rapid root growth and form an extensive root system to tap water from the soil in a most efficient manner. The leaf size is greatly reduced and in many xerophytic grasses, leaves roll on to reduce the leaf surface for restricting loss of water due to transpiration. Some of the examples are Calotropis procera, Acacia nelotica, Saccharurn munja In non-succulent xerophytes, root system is very extensive e.g. Calotropis.
Oligosaccharides are short chains of monosaccharides linked together by glycosidic bonds. In case of oligosaccharides linked to proteins (glycoproteins) or lipids (glycolipids) o
Which type of chemical bond maintains the pairing of each chain in the DNA molecule? To produce the DNA molecule, purine bases bind to pyrimidine bases by intermolecular bonds
Q. How does photosensitivity in annelids, cnidarians and worms differ from insects, cephalopods and vertebrates? In the first mentioned group of animals there are photoreceptor
importance of pyramid of energy to the ecologist
Is it possible for any son of a couple formed by a hemophilic man (XhY) and a nonhemophilic noncarrier (XX) woman to be hemophilic? If the mothers are not affected by the disea
Q. What do you mean by Punch cards? Punch cards are used when the number of taxa to be keyed out is large. In this type of cards the holes at numbers corresponding to a charact
Explain the Copper Toxicity in Human? Acute copper toxicity in humans is rare and occurs due to inadvertent consumption of copper salts. Symptoms include vomiting, diarrhoea, h
Active Transport We have mentioned above that Transmembrane potential develops due to active transport of ions (H + ) outside the cell. Since this transport takes place again&
how can we make an assignment for the subject alimentary canal
Four major groups of lipoproteins help in transport of lipids. These include: 1. Chylonzicrons-function is to carry dietary triacylglycerols 2. Very low density lipoprot
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd