Answer: Option A
Explanation:
A paraphyletic group can be defined as the group of organism that includes the ancestors but not all of its descendants.
There are three kinds of phylogenetic groups that can be understood by the help of the diagram.
The phylogeny can be defined as the diagram which shows the evolutionary relationship of one organism from another.
Other groups are monophyletic groups, parsimonious et cetera which shows different evolutionary relationship with organisms.
It penetrates the skin and can cause mutations.
Answer:
-Histamine binds extracellularly to the H1 receptor.
-When histamine binds to the H1 receptor. the receptor undergoes a conformation change and binds the inactive G protein.
-Once the G protein is active, it binds to the enzyme phospholipase C, activating it.
-Histamine is likely hydrophilic.
When histamine encounters a target cell, it binds extracellularly to the H1 receptor, causing a change in the shape of the receptor. This change in shape allows the G protein to bind to the H1 receptor, causing a GTP molecule to displace a GDP molecule and activating the G protein. The active G protein dissociates from the H1 receptor and binds to the enzyme phospholipase C, activating it. The active phospholipase C triggers a cellular response. The G protein then functions as a GTPase and hydrolyzes the GTP to GDP. The G protein dissociates from the enzyme and is inactive again and ready for reuse.
Explanation:
Answer:
short answer: The Earths atmosphere
Explanation:
The Earth's atmosphere protects us from the multitude of small debris, the size of grains of sand or pebbles, thousands of which pelt our planet every day. So the probability of a major collision is quite small
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