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

Sunshine recorder, Sunshine recorder Sunshine recorder (Figure shown be...

Sunshine recorder Sunshine recorder (Figure shown below) measures the duration of sunshine. The recorder consists essentially of a glass sphere of about 10 cm in diameter mount

Determine the nucleus transplantation technology, Why are the recombinant D...

Why are the recombinant DNA technology and the nucleus transplantation technology still dangerous? The recombinant DNA technology and the nucleus transplantation technology (cl

What in genetics is hybridization, What in Genetics is hybridization? T...

What in Genetics is hybridization? The Hybridization in Genetics is the crossing of individuals from "pure" and different lineages in relation to a given trait that is the cros

Xenotransplantation, X e n o t r a n s p l a n t a t i o ...

X e n o t r a n s p l a n t a t i o n Over the past 20 years transplantation of heart and kidney has become almost a routine in human but the availability of

What is autophagic intracellular digestion?, Autophagic intracellular diges...

Autophagic intracellular digestion is the cellular internal digestion of waste and residual materials. In general it is completed by lysosomes. Autophagic intracellular digestio

Why is aids difficult to prevent by vaccination, Why is AIDS difficult to p...

Why is AIDS difficult to prevent by vaccination? It is complex to produce a vaccine against AIDS because the HIV is a highly mutant virus. In almost every replication the produ

Which of the following statements is not true of mitosis, Which of the foll...

Which of the following statements is not true of mitosis? A. The original cell produces two identical daughter cells B. It follows duplication of DNA in the nucleus C. It involves

Explain lipid formulations, Explain Lipid Formulations Three lipid form...

Explain Lipid Formulations Three lipid formulations of amphotericin B are marketed in the US: amphotericin B lipid complex (ABLC, Abelcet), liposomal amphotericin B (L-AmB, AmB

What are d-glucose and d-galactose, D-glucose differs from D-galactose onl...

D-glucose differs from D-galactose only in the arrangement around carbon 4. Therefore D-glucose and D-galactose are- Select one: a. enantiomers b. epimers c. mirror ima

Spider naevus, Spider Naevus: It  is found on  the cheeks,  nose  and ...

Spider Naevus: It  is found on  the cheeks,  nose  and  sometimes other parts of the  face  as a central  bright-red vessel about  the size of  a pin-point with smaller vessel

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