Answer:
The correct answer is- Nirenberg and Heinrich, 1961.
Explanation:
Experiments by Marshall Nirenberg and Heinrich Matthaei in 1961, began to decipher genetic codes and state about the 64 triplet codons in the genetic code by using mRNA from DNA to translate into specific amino acids in our biological system.
Their experiment helps to decode or crack the code of DNA by establishing the first codon out of 64 triplet codes which are  UUU codes for phenylalanine. In the future, the same approach is used to find other amino acids.
 
        
             
        
        
        
You can only make one zygote but in some cases the egg splits and makes an identical twin. 
 
        
             
        
        
        
Answer:
Single-cell organisms
Explanation:
In 1735, Linnaeus introduced a classification system with only two kingdoms: animals and plants. Linnaeus published this system for naming, ranking, and classifying organisms in the book "Systema Naturae". In the epoch that Linnaeus created this system, single-cell organisms such as bacteria and protists were almost unknown. In 1866, E. Haeckel added a category including both bacteria and protozoa, thereby adding a category formed by single-cell organisms (different from animals and plants). During the 1900-1920 period, bacteria were classified as a separated kingdom named 'prokaryotes'. The current three-domain classification system was introduced by C. Woese in 1990. In this system, all forms of life are divided into three different domains: archaea, bacteria, and eukaryote domains (this last composed of protists, fungi, plants and animals).
 
        
             
        
        
        
Answer:
A
Explanation:
prometaphase  is the process that seperates the duped genetic meterial carried on a nucleus