Answer:
option D: GABA ( gamma-aminobutyric acid )
Explanation:
The amount of neurotransmitters released during depression can not be properly measured. The neurotransmitters released due to anxiety are GABA, serotonin, Cck, and glutamate. 
The rise in level of neurotransmitter, GABA in depression causes anxiety. Thus, option D is correct.
 
        
             
        
        
        
Answer:B. is false
Explanation:
Once RNA polymerase and its related transcription factors are in place, the single-stranded DNA is exposed and ready for transcription. ... Three of the four nitrogenous bases that make up RNA — adenine (A), cytosine (C), and guanine (G) — are also found in DNA.
 
        
             
        
        
        
Melanin provides pigmentation to the skin and it also provides UV ray protection (which is its role in the epidermis).  
        
             
        
        
        
<span>The answer is D) atmosphere. There are four spheres of the Earth: 1. Lithosphere (from Greek word 'lithos' = rock), 2. Hydrosphere (from Greek word 'hydros' = water), 3. Biosphere (from Greek word 'bios' = life), and 4. Atmosphere (from Greek word 'atmos' = air). Condensation is the change of water vapour into the water, i.e. the change of water from its gaseous form into liquid form. Since water vapour is the part of air, condensation occur in the atmosphere.</span>
        
                    
             
        
        
        
Answer:
Factors that remain constant from experiment to experiment are the constants.
Explanation:
A constant in an experiment is also known as a <em>control variable</em>. It is the part of an experiment that must stay the same in order to validate the experiment. If the constant were to change, the results would be skewed and therefore false.
i.e. you want to test the rate of growth of lima bean plants in different types of lighting. You believe that a lima bean plant that grows in yellow will grow faster and stronger than a lima bean plant that grows in blue or red light.
In this experiment, the constant would be the lima bean plant. You cannot change the type of seed or else your experiment is invalidated. If you tried to use a sunflower seed in the blue lighting and a tomato seed in the red lighting, your results would be invalidated and skewed.