Answer:columnar describes cell shape.
Simple describe the number of layers 
Explanation: epithelial tissues are one of the four major tissues of the body.the others being nervous, muscular, connective tissues.
Epithelial tissues are made up of thin cells that cover the external and internal surface of the body.
The cells may form one layer or more and they occur in several shapes.if they form one layer ,it is called simple.if they form several layers,it is called stratified.
Some are called pseudo-stratified because the cells occur with varying lengths and give the impression of stratified but they are actually made up of one layer.
Simple columnar epithelium is a single layer of tall, closely packed cells. They possess cellular extensions ,such as microvilli in the small intestine, or the cilia in the female reproductive tract. 
 
        
             
        
        
        
Answer:
active transport, like Na + ions leaving the cell
Explanation:
The active transport requires an energy expenditure to transport the molecule from one side of the membrane to the other, but the active transport is the only one that can transport molecules against a concentration gradient, just as the diffusion facilitated the active transport is limited by the number of transport proteins present.
Two major categories of active, primary and secondary transport are of interest. The primary active transport uses energy (generally obtained from ATP hydrolysis), at the level of the same membrane protein producing a conformational change that results in the transport of a molecule through the protein.
The best known example is the Na + / K + pump. The Na + / K + pump performs a countertransport ("antyport") transports K + into the cell and Na + outside it, at the same time, spending on the ATP process.
The secondary active transport uses energy to establish a gradient across the cell membrane, and then uses that gradient to transport a molecule of interest against its concentration gradient.
 
        
             
        
        
        
Cell differentiation is the process by which cells specialize to achieve their required functions. In order for a cell to differentiate, it will express specific genes. ... Importantly, mitosis produces cells that are identical to each other (clones).
 
        
             
        
        
        
Answer:
b. Forward or reverse primers
Explanation:
Sanger sequencing is a technique of DNA sequencing based on the extension of DNA fragments with variable sizes terminated with dideoxynucleotides at the 3′ end. This technique was developed by Frederick Sanger in 1977. In Sanger sequencing, a short primer is added in order to bind by complementarity to the target DNA region of interest. Subsequently, a DNA polymerase adds nucleotides (A, T, C and G) in the 5'-3' direction. Finally, the extension of the DNA strand is stopped by adding dideoxynucleotides, which are nucleotide analogs (i.e., modified nucleotides) that act as DNA synthesis terminators.
 
        
             
        
        
        
Hulk syndrome, when you get mad and turn green