Answer:
miR-223 inhibits the expression of the fibroblast growth factor (bFGF) gene, and thereby ESCs cells maintain their undifferentiated state
.
Explanation:
Non-coding RNA (ncRNAs) are molecules that regulate gene expression, thereby playing important biological functions in cell differentiation, cell cycle, apoptosis, etc. MicroRNAs (miRNAs) are a type of ncRNAs capable of controlling gene expression patterns by regulating mRNA stability and by suppressing their translation into proteins. It has been shown that miRNAs function by imperfectly base-pairing with the 3′ UTR of target mRNAs (Pillai et al. 2005).
Citation:
R. S. Pillai, S. N. Bhattacharyya, C. G. Artus,   T.  Zoller, et al. (2005). Inhibition of translational initiation by Let-7 MicroRNA in human cells. Science, 309(5740), 1573-1576.
 
        
             
        
        
        
Answer:
For conduction
A. 
air molecules touch the warm ground, heating them up because conduction is the transfer of energy through direct contact
For convection
B. 
 Warm air rises and takes heat with it; eventually it cools and sinks. 
Explanation:
 
        
             
        
        
        
<span>D: Viruses
I hope helped ^-^</span>