Crossing over? That involves the random exchange of chromosomes.
The answer to this would be D: physical components of the environment, such as rocks and sand. The word "biotic" mean all the living organisms within an ecosystem such as plants and animals.
I would also say that the answer is C
Answer:
solid, naturally occurring, inorganic, fixed composition, crystal form.
Explanation:
Answer:
The correct answer is -
the neurotransmitters are broken down in the synapse
The presynaptic neuron absorbs the neurotransmitters
Explanation:
The termination of the neurotransmitters is essential as if they can cause harm by continuing the stimulus effect on the muscles or cells. To clean up these neurotransmitters there are two ways- Degradation of neurotransmitters with the help of enzymes in the synapses or synaptic cleft and the presynaptic neurons absorbs or suck up neurotransmitters. The neuron (presynaptic neuron) is that releases the neurotransmitter like dopamine, serotonin, is the one that re-uptake it.
This reuptake is done by transporter proteins that are are symporters in nature as these proteins pump neurotransmitters as well as ions back into the neuron.