B. a specific place on a chromosome where a particular gene resides.
A locus (plural loci) in genetics is the position of a gene on a chromosome. Each chromosome carries many genes; humans' estimated 'haploid' protein coding genes are 19,000-20,000, on the 23 different chromosomes. A variant of the similar DNA sequence located at a given locus is called an allele.
Your answer is C lithosphere because the availability of phosphorus is different than that of carbon and nitrogen because it is found mostly at the lithosphere.
Answer;
-Neurotransmitters.
One of the first key terms she memorizes is neurotransmitters because these are the chemicals via which neurons communicate with each other.
Explanation;
-Neurons communicate with each other via electrical events called 'action potentials' and chemical neurotransmitters. At the junction between two neurons (synapse), an action potential causes neuron A to release a chemical neurotransmitter.
-Neurons are connected to each other through synapses, sites where signals are transmitted in the form of chemical messengers.
