Answer:
option A 
Explanation:
because plants give oxygen 
 
        
                    
             
        
        
        
A neurotransmitter can have an excitatory or inhibitory effect on the postsynaptic cell, depending on <u>which of its </u><u>receptor(s</u><u>) are present on the </u><u>postsynaptic</u><u> (target) cell.</u>
<h3>How do excitatory and inhibitory neurotransmitters act?</h3>
Sometimes neurotransmitters can bind to receptors and cause an electrical signal to be transmitted through the cell (excitatory). In other cases, the neurotransmitter can prevent the signal from continuing, preventing the message from being carried (inhibitory).
With this information, we can conclude that a neurotransmitter is a signaling molecule secreted by a neuron to affect another cell across a synapse. 
Learn more about neurotransmitter in brainly.com/question/9725469
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Yearly dental visits are a part of good dental hygiene because the dentist will check for cavities, fix them, clean your teeth very thoroughly (or whitening treatment), and check the progress and movement of your teeth. They can also recommend when dental surgery is necessary, for instance, if you have extra teeth that can be removed or when your wisdom teeth are coming in. Hope this helps! :)
        
                    
             
        
        
        
Diagram found elsewhere attached
Answer:
Clockwise from bottom
3. formation of mRNA in the nucleus
6. secretion of hormone  by tissue
4. initiation of DNA  replication because  of a signal given  by the hormone
2. synthesis of protein  molecule by mRNA  and tRNA
1. secretion of protein  by the cell
5. binding of the  hormone molecule  with its receptor  of the cell
Explanation:
The tissue in the top left releases a hormone. For example, a steroid hormone such as estrogen, which can impact gene expression at the level of transcription. This hormone then travels to a different cell to carry out its function. The hormone is able to enter the cell and binds receptors which recognise it. In this case, these receptors are present in the nuclear envelope. When the hormone has bound the receptor, it initiates a signalling cascade that the cell responds to.
In this case, the effect of the signal from the hormone is to initiate DNA replication. This is a common effect of hormones such as growth factors that signal the cells to proliferate. 
The initiation of the signalling can  also affect how genes are expressed. In this case, an mRNA is produced in the nucleus, which is created as a result of transcription. This mRNA molecule then moves to the cytoplasm, where it becomes translated into a polypeptide sequence at a ribosome, with the help from transfer RNAs (tRNAs). 
This polypeptide forms a mature protein by progressive folding and potential modifications, and is released by the cell to perform its functions.
 
        
             
        
        
        
Answer:
Matter is conserved because atoms are conserved in physical and chemical processes. As complex as the water cycle is, water molecules are conserved and endlessly recycled in nature. Conservation of mass is a physical law that s never broken.This cycle continues with no loss of water.