<span>indicate a common ancestor exists between two organisms
</span>
NOT:
result from evolution in a similar environment
are features which organisms still have but no longer use
<span>develop when a mutation occurs in the DNA of an organism</span>
Answer:
1. Signaling molecule
2. Signaling receptors
Explanation:
Hormones, growth factors, neurotransmitters, etc. serve the function of signaling molecules for cells. These molecules are released by one cell and bind to the receptors present on/in the target cells to elicit the desired response. Thereby, the signaling molecules serve in cell-cell communication.
For example, insulin hormone synthesized and released from beta cells of pancreas binds to its cell surface receptors present on the surfaces of liver cells and muscle cells to stimulate the uptake of the glucose from the blood.
Likewise, neurotransmitters released from the presynaptic neuron bind to receptors present on the membrane of postsynaptic neuron and serve to carry the nerve impulse to the postsynaptic neuron.
Answer:
11: Independent variable
12: Sink
13: Depends on whether your teacher will let you play once a lesson is over but in most classrooms I would say it is not allowed
14:Theory
15: Objective
16: 3
Explanation:
Glial cells. More specifically, it could be oligondenrocytes, astrocytes, ependymal cells, schwann cells, microglia, or satellite cells, because they are all types of Glial cells.