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.
Topsoil is the most fertile soil layer for plants.
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.
