Answer:
Medical Definition of erythrocytopenia
: deficiency of red blood cells. — called also erythropenia.
Explanation:
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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! :)
Answer and Explanation: This is true that theories do change or get replaced overtime. We all know that in any scientific investigation the scientist put forth the theories which are basically the ideas explaining something particular. We also know that the world is experiencing constant changes and those changes could be of Technology or of overall world order so, whenever a scientist gives us the theory, that theory is made according to the situations and environment of that particular time and in future with the passage of time and with the advancement of Technology and other variables, scientist do need to re-evaluate theories. They either make some positive changes keeping in view the changing circumstances of the current situation or discard the theory altogether depending on its nature. The name research itself indicate that scientists research the already searched idea and in that way the New theory which comes after the modification of old theory or altogether the new theory takes place of the old one.
Answer:
A
Explanation:
it is the amount of energy required to activate the reaction.
