The correct answer is option A. They either match up with a receptor molecule on the surface of the cell or enter the cell through the membrane.
The intercellular signals are the signals, which transfer the signals from one cell to the another and the intracellular signals are those signals, which carries message within the cell.
The intercellular signals may or may not be transferred through the gap junctions. The chemical signals are one of the type of the cell signals. The chemical signalling molecules generally have a receptor on the cells, where these molecules can bind and can be cause the activation of the cell. The chemical signals can also enter into the cells through active transport and facilitated diffusion. So, these type of transports does not go through the Gap junction.
<u>Answer:</u>
Approximately, the oldest stromatolites are 3.6 billion years old on earth.
<u>Explanation:</u>
- Stromatolites is not only oldest earths fossil but conspiracy in that they are singular visual portal in deep time on earth.
- It is defined as laminated accumulation structure that is they stick up above sea floor .
- Stromatolite buildings includes oldest fossils which are 3.5 billions old when the earth were too unfriendly to support life.
- The study of fossil age, evolutionary, method of formation are known as paleontology.
- These specimens are considered as old fossils which are around 3.4 to 4.1 billions years old.
Answer:
the wind
Explanation:
the speed of wind could affect a storm adding with the rain
Answer:
Active transport often takes place in the internal lining of the small intestine.
Explanation:
