Extremes of heat and cold, Biology

Extremes of Heat and Cold

Deserts are regions of aridity with rainfall of less than 20 cm per year and the soil, though L, fertile, is too porous to retain any water. In summer there is great diurnal variation in temperature from 40°C during the day to below 15°C the same night. The light intensity reaches higher peak due to lack of cloud cover. The true deserts are Sahara in Africa and Great desert in Australia where the annual rainfall is less than 2 cm. Plants and animals which survive under such conditions have special features that allow them to withstand high temperature and lack of water.

The other extreme of temperature is seen in the arctic and alpine tundras. The word tundra means bare mountain tops in Finnish. Tundras are kozen most of the year round and are very similar to deserts as the rainfall here is also about 20 cm per year. But during the short summers, water is plentiful as the topmost layer of ice melts. The ground gets covered with short grass and patches of moss and lichens. Beneath the thawed layer of 3-5 cm, the soil called permafrost remains permanently frozen. Since the roots cannot penetrate deep in the soil trees do not grow here.

Posted Date: 12/10/2012 6:35:49 AM | Location : United States







Related Discussions:- Extremes of heat and cold, Assignment Help, Ask Question on Extremes of heat and cold, Get Answer, Expert's Help, Extremes of heat and cold Discussions

Write discussion on Extremes of heat and cold
Your posts are moderated
Related Questions
Immunogenicity Based on immunogenicity studies and experience with other vaccines, the new meningococcal conjugate vaccine (Menactra) should be highly effective in preventing m

Determine the function of human body system Human body has different systems to perform different functions. A system consists of organs to perform a particular set of function

Q. What are the main bryophyte groups? The major bryophyte groups are the mosses, the hornworts and the liverworts.

Define Health Benefits of Other Dietary Factors with Antinutritional Effects? Despite the predominantly nutritional antagonistic effects of the factors described above, there i

Q. What is Ocean shorelines? Ocean shorelines include rocky coasts and sandy beaches that are particularly rich in diverse life forms. Rocky shorelines support a diversity of o

Phosphorus Phosphorus has been known as “master mineral” because it is involved in most metabolic processes. Phosphorus, which is stored in bones and teeth, is often discussed

In a possible future scenario, male fertility drops to zero, but, luckily, scientists develop a way for women to produce babies by virgin birth. Meiocytes are converted directly (w

Define the Coenzyme activity of nicotinic acid? Nicotinamide exists within the redox-active coenzymes,  nicotinamide adenine dinucleotide (NAD) and its phosphate (NADP), which

comparitive chart on different types of respiration obserbed in different type of respiration organ of respiration , types of respiration,energy obtained , by product formed

Q. Explain Clostriduim botulinum? Clostriduim botulinum is widely distributed in soil and marine sediments throughout the. world. It is also found in the intestinal tract of a