Answer:
Eutrophication
Explanation:
Greek word meaning "well-nourished"
<span>The answer is a certain required chemicals must be actively
transported. Blood brain barrier is a
selective membrane that separates blood circulating from the brain and the
fluid of extracellular in the central nervous system. This is also called a
filtering mechanism, the capillaries that carry blood to the brain and spinal
cord tissue blocking the path way of the certain substance.</span>
Answer:
A
Explanation:
Thick clouds can trap lots of heat. This has a warming effect on earth.
Answer:
Lack of oxygen
Explanation:
There are two mechanisms for energy production (glucose breakdown), aerobic and anaerobic. When adequate amounts of oxygen are present, aerobic mechanism is used. However, when there is insufficient oxygen, such as during exercise, the anaerobic mechanism is used.
<u>Answer:</u>
Recent evidence suggest that feathers evolved from scales and suggest that 'feathers and pycnofibers' could be homologous.
<u>Explanation:</u>
- One of the major difficult issue related to bird evolution is the evolution of feathers.
- Feathers are considered as the most 'complex integumentary structures' which are found in vertebrates.
- Evolutionary developmental biology suggests that the 'planar scale structure' is been modified for developing into feathers by 'splitting' to form web like structures.
- Scales and Feathers consist of 'two distinct form of keratin' so it was thought that 'each type was exclusive skin structure' but recent study suggests that they are developmental expressions of same skin structures.
