Tolerance to cold and freezing temperatures, Biology

Assignment Help:

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.


Related Discussions:- Tolerance to cold and freezing temperatures

Define hocm murmur characteristics in details, Define HOCM Murmur character...

Define HOCM Murmur characteristics in details? Characteristics: The murmur is harsh, crescendo-decrescendo audible along the left sternal border, radiates to the base of heart

Etiological factor of diverticular disease, Q. Etiological factor of divert...

Q. Etiological factor of diverticular disease? The causes of diverticular disease are not certain, but several factors may contribute to changes in the wall of the colon. These

Menstrual cycle- reproduction, Menstrual Cycle- Reproduction Menstrual...

Menstrual Cycle- Reproduction Menstrual cycles are characteristic of primates and do not occur in other vertebrate groups. The length of the cycle is highly variable, though 2

What would be a very wrong way to tell the difference, You have accidentall...

You have accidentally mixed up 3 beakers of solutions. One is water. One is pure methanol. One is pure phosphoric acid. What would be a very wrong way to tell the difference betwee

Explain about gout disease, Q. Explain about Gout disease? Gout is a ch...

Q. Explain about Gout disease? Gout is a chronic disease due to an inherited abnormality of purine metabolism. What are purines? You may recall studying about purines and their

Results of monohybrid crosses, Results of Monohybrid Crosses Mendel got...

Results of Monohybrid Crosses Mendel got the following results from his monohybrid crosses :- 1.         F 1  plants produced by a cross between two plants pure for the cont

Type one diabetes mellitus, Q. Type one Diabetes Mellitus? Type 1 DM oc...

Q. Type one Diabetes Mellitus? Type 1 DM occurs in children and adolescents (6-14 yrs). In this disease, the body makes little or no insulin. Daily injections of insulin are ne

All part., Wat type of animal is tick and weevil?

Wat type of animal is tick and weevil?

What is complete transposition of arteries, What is complete transposition ...

What is complete transposition of arteries? Complete transposition of the great arteries (dTGA): The atria and ventricles are connected appropriately i.e., the right atrium dra

Is cancer a disease transmitted to the individual offspring, How are mutage...

How are mutagenic agents related to cancer incidence in a population? Is cancer a disease transmitted to the individual offspring? The exposition of a population to mutagenic a

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