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!
Tolerance to Cold and Freezing Temperatures
In the earlier section you have been studying about tolerance of animals to high temperature. Now in this subsection we will study about tolerance to cold and freezing temperatures. The effects of low temperature are equally perplexing as those of high temperature. Some organisms can tolerate extensive freezing but most animals cannot. Animals that live in '4 temperature and cold regions are often exposed to long periods of winter temperatures that are far below the freezing point of water. Survival of ectothermic animals at such subzero temperature depends upon the physiological and biochemical characteristics that can be described as cold hardiness. An animal can develop cold hardiness either by developing capacity for freeze tolerance or by avoiding ice formation even if exposed to temperatures as low as -40°C to -50°C. The latter are regarded as freeze intolerant.
The intertidal marine invertebrates of colder zones are freeze tolerant in the sense that they survive extensive ice formation within their bodies. Many other animals also survive in spite of extensive ice formation. For example, midge Chironomous larva from Alaska can be frozen and thawed repeatedly without injury. Several species of insects are known to contain high concentration of glycerol in their body fluids. It is well-known that glycerol protects red blood cells and mammalian spermatozoa from injury caused by freezing. Therefore, glycerol is widely used for this purpose and samples of human or bull sperm can be kept frozen and viable for several years using glycerol. Without such treatment, freezing is Iethal, to sperms. Only a few vertebrates tolerate extensive ice formation. Birds and mammals however, are not known to tolerate freezing.
Define measuring body composition- Total body potassium? It applies the' concept that body cells contain a constant amount of potassium and that its measurement is theref
Q. What are the periods of the second meiotic division? Meiosis II is divided into metaphase II, prophase II, anaphase II and telofase II.
Q. Show the Chemical indicators used in sterilization cycle? Chemical indicators indicate the presence of certain conditions during the sterilization cycle, such as the presenc
Asymmetric carbon atom : a carbon atom attached with four different groups or atoms.
using either nested brackets as a cladogram, what are the hierarchical relationships among the followingtaxa:raniates, amniotes, mammals, actinopterygians, chondrichthyes, aves, ve
Testing for urine sugars is not recommended for either diagnosis or monitoring of patients with diabetes. This is because a urine sugar is not a reliable test. When no facilities a
Q. Pain - criteria for endosteal implants? Pain and tenderness are subjective criteria and depend on patient's interpretation of the degree of discomfort. Pain is defined as u
Bioinert Metals:- Commercially pure titanium/ titanium alloys Ceramics:- Aluminum oxide, zirconium oxide
Problem of Potency of Blastema Cells The local cells are accountable for regeneration. Now you could ask which of the blastema cells differentiated into which type of limb ti
Endocrine glands
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