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

Dna, Double helical structure of dna

Double helical structure of dna

Aschelminthes, In what part of the human body ASchelminthes found?

In what part of the human body ASchelminthes found?

Why all specialization occurred during this time period, There is a lot of ...

There is a lot of dataset and hypothese that attempt to explain why there was a Cambrian Explosion. Using all supporting ideas, explain and write a paragraph on why all this specia

Obelia, why is obelia considered to of special interest in Zoology as an an...

why is obelia considered to of special interest in Zoology as an animal showing an intermediate grade of organisation?

Describe rna sequence, Q. What is the name of an RNA sequence that codifies...

Q. What is the name of an RNA sequence that codifies one amino acid? Each sequence of three nitrogen-containing basis of RNA that codifies one amino acid is called a codon. The

Spleen, SPLEEN Largest lymph gland, also with myeloid tissue is an i...

SPLEEN Largest lymph gland, also with myeloid tissue is an important specialized reticuloendothelial organ in vertebrates, as the site of erythropoiesis. Splenic tissue i

How dietary constituents affecting the calcium absorption, How dietary cons...

How dietary constituents affecting the calcium absorption? Several dietary constituents have an effect on calcium absorption. The differences in fractional absorption from diff

Valvular heart diseases, Valvular heart diseases :  Congenital and acquire...

Valvular heart diseases :  Congenital and acquired valvular heart diseases often require surgical intervention. 1 is well known that conservative surgery by valve repair gives bet

Science as a human endeavour, Science as a human endeavour: Science is...

Science as a human endeavour: Science is a human endeavour. Human beings, from prehistoric times, attempted to control nature for their own welfare. For this, they had to ob

Plate tectonic theory, Plate Tectonic Is a Theory of Geology Which describe...

Plate Tectonic Is a Theory of Geology Which describes the large scale motion of earth's lithosphere. The theory builds on the older theory of continental drift from the first half

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