Answer:
A = Activator
B = Effector
Explanation:
An activator is a protein which typically binds to a short (50–1500 bp) region of DNA which might be located either upstream (mainly) or downstream of a gene so as to cause increased transcription. This particular region of DNA is known as enhancer and activator is also known as transcription factor. Activator is a trans-acting factor which binds to the cis-acting factor which is enhancer so as to enhance transcriptional expression.
But another protein named as effector may restrict activator from binding to the enhancer leading to a decrease in transcriptional expression by binding to the activator allosterically. Allosteric binding of effector to the activator causes conformational change in activator so it can no longer bind the enhancer.
The answer to this question would be: parasympathetic division
Parasympathetic nervous is part of the autonomous nervous system. In the autonomous nervous system, the sympathetic system is used when you enter the "fight or flight" mode. In this case, the body will be prepared to be able to take a decision as quickly as possible in a strenuous state. The nervous also cause an increase in the heart and breathing rate to increase body capability.
Parasympathetic is the opposite of it which was activated to calm the body so it can maintain the normal body function.
Multicellular organisms use different types of cells to function not just one cell. If cells grew larger that cell would be more demanding.
Answer:
Continental drift
Explanation:
Alfred Wagener told about continental drift. He said that continents were a single land mass called Pangaea. They were separated and relocated in the form of different continents. The drifting happens due to the movement of tectonic plates above the magma. As a result, the land mass was broken down into different landforms. These broken parts were carried slowly and form the continents. The continents are now also moving slowly
