Answer:
Option A , Genome
Explanation:
Microarrays that contains array of single stranded DNA are used to study thousands of gene expression for all the genes of a genome and are usually termed as DNA miscroarrays. These microarrays being single stranded allows attachment of complementary DNA strand to bind to their surface. The mRNA from the cell is extracted and converted into cDNA which is further used for DNA cloning.
Hence, option A is correct
 
        
             
        
        
        
Both answers C. and D. are correct. Most marine animals live in pods like seals, whales, and walrus. A. is called a school of fish while B. is a colony of penguins. :(
        
             
        
        
        
Any genetically engineered organisms is referred to as a transgenic organism.
A transgenic organism is any organism that was modified genetically or engineered by humans, for certain purposes, in this case, the function of the thale cress is to break down toxic metals in the water (cress plants grow on water).
Hope it helped,
Happy homework/ study/ exam!
 
        
             
        
        
        
B. How far do butterflies migrate 
A, C and D are opinions not facts.