Answer:
When both _signal molecules_ are in their receptor sites, the molecules form a dimer (two molecules joined together). ATP is converted to ADP and the _phosphate group_ gets attached to the tyrosine molecules. The addition of the _ relay proteins_ causes a cascade of cellular responses.
Explanation:
I have added explanation as image form so it will help you understand more easily.
Scientists believe the earth is approximately 4 1/2 billion years old
Natural selection affects or changes a population and not only an individual organism because as there are somethings to be changed in a certain organism to adapt to the changes in the environment, all organisms in a certain species will be able to adapt and the changes therefore is collective.
Answer:
Most of the earliest microorganisms were prokaryotes so it would make sense for them to go through photosynthesis to create glucose for energy. They also could have gotten energy from salt water.
Explanation:
A human cheek cell is thin, flat and has a large nucleus that contains the DNA. Its plasma membrane helps the cell to maintain suitable temperature while giving it its shape. Since it is selectively permeable, it only allows certain molecules into and out of the cell.
