Tundra and deserts are two biomes of the world which represent the extreme form of climates. Tudra is the coldest region of the earth while desert represent the hottest zones of the earth. But whats the most common thing in these extreme zones is that they receive very less precipitation throughout the year (less than 25 cm).
Therefore, flora of the desert and Tundra have some special adaptations to survive without sufficient amount of water.
Let's see what are those:
- The height of plants growing in Tundra is very less like lesser than 1 foot. The short structure of the plants helps them to get more heat from the dark soil and helps to survive freezing. The short height lets them stay protected from harsh effects of cold or snow.
- The plants in tundra grow in groups or clumps that helps them in surviving the attacks of ice particles or snow balls. For example: lousewort and Arctic crocus.
- Some flora of tundra has ability to grow even in the complete lack of water for several years.This is because they have waxy layers that cover the leaves and store maximum water for the periods of no availability.
- Some plants have hair on the surface of stems that trap maximum heat and protect the plant from heat and extreme forms of wind. For example: Arctic crocus.
- Desert plants not only have physiological but also morphological adaptations to survive heat stress and shortage of water. Their stems, roots and leaves are fleshy and help them to store water for a large period of time. For example: Cactus
- Many desert plants like <em>xerophytic bromeliads</em> and <em>epiphytic orchids </em>contain a system alternate of photosynthesis called CAM (Crassulacean Acid Metabolism). This process helps the plant to open the stomata at night for exchange of gases and accumulate CO2. In day, stomata are closed and the CO2 is used for photosynthesis. This is an adaptation, because during night when temperature is low, CAM plants lose less water as compared to what normal plants lose during day.
- Some plants have extremely large roots that absorb maximum water from soil and compensate the plant's loss of water due to heat. For example: Phreatophytes.
- Some Perennial plants have adapted the mechanism to stay in condition of rest or dormant during extreme heat. They get back to normal life when weather become a bit better.
Hope it helps! :)
A water molecule (H2O) will have a slightly positive side, and a slightly negative side. The oxygen side of water is the one that is negative, while hydrogen side tends to be more positive. When a molecule has a half negative and half positive side like water does, it is called a polar molecule. :D
Answer:
i believe it's the first one
Explanation:
Answer:
"Autonomic nervous system" is similar to the autopilot of the airplane
Explanation:
The autonomic nervous system is a portion of the govern system which regulates the metabolic or the physiological processes of the human being. Inside the brain the autonomic nervous system is controlled by the hypothalamus. On the other hand the autopilot of the airplane is the combination of the system that are required for the automatic operation of the plane. Hence, both the things are similar but works for different process.
Answer:
Adenine on one strand can pair only with thymine on the other strand; cytosine, only with guanine.
Explanation:
DNA nucleotides can contain one of four nitrogenous bases. These bases are adenine (A), thymine (T), guanine (G) and cytosine (C). The two strands are held together through hydrogen bonds that form between the nitrogenous bases. Adenine (A) forms bonds with thymine (T) while cytosine (C) forms bonds with guanine (G); A only ever pairs with T, and C only ever pairs with G.
