Answer :Erwin Chargaff a Biochemist
Explanation:
He formulated the base paring of double helix of DNA. He reasoned that since the percentage of four DNA bases are of this proportions in human;
Adenine=30.9% and Thymine =29.4%;
Guanine=19.9% and Cytosine =19.8%
Then, the amount of adenine will always be equal to thymine,
And the amount of Guanine equals to cytosine based on this percentages of distribution.
(Adenine and Guanine are large, molecule of Purines, while thymine and Cytosine are Pyrimidine)
He concluded (although scientist believed, he did not explicitly stated this) that this should be the base paring patterns in DNA molecule. This is the first Chargaff Rule.
His second rule is that the DNA composition, in the relative amount of the four bases Adenine, Thymine, Cytosine and Guanine varies in proportion from one organisms to another. And this is the basis of molecular diversity.
The function of tRNA is to read the messages of the nucleic acids, and then translate it into amino acids.
Answer:
be happy
Explanation:
get enough rest and eat good
The term ‘Crossing over’ was used by Morgan and Cattell. It is a process in which there is exchange of chromosome segments between non-sister chromatids of a homologous chromosomes. It occurs during pachytene stage of prophase I of meiosis cell division.
Significance of crossing over:
- Crossing over provides genetic variation in all sexually reproducing organisms.
- It creates new combination of genes or genetic recombination and produces hybrids.
