2 Flashcards
What is DNA?
DNA is the control molecule of life
What does dna control?
DNA controls cellular activities, including reproduction
What does dna make
DNA makes exact copies of itself to pass onto other cells
What does dna carry
DNA Carrie’s a code. Genetic instructions are encoded in the sequence of bases strung together in DNA.
What is the source of the unity of life
DNA
What are the sources of life’s variation?
Mutations and recombinations in the structure and number of DNA molecules are the source of life’s variation.
How did life most likely begin?
Life most likely began as a nucleic acid. The first form of life on this planet is thought by many biologists to be a self-replicating strand of RNA
What are the two types of nucleic acids
DNA / RNA
Who was DNA first isolated by?
By Swiss biochemist Johann Friedrich Miescher in 1869. Because DNA molecules are acidic and are found in the nucleus Miescher called them nucleic acids.
Who determined the mechanism for DNA replication
Meselson and Stahl determined it in 1958. In the genetic code of 3 dna nucleotides for 1 amino acid was worked out by Crick and his coworkers
During the 1950s a fierce competition to determine the three dimensional structure of dna took place. Who was the race won by in 1953?
James Watson, an American biologist and Francis Crick, a British physicist. Solved the puzzle using scale modes of nucleotides at Cambridge university in England. Their success depended to a great extent on evidence collected by other biologists especially x ray data from British biochemists Rosalind Franklin and Maurice Wilkins
What is the monomer of a nucleic acid
Nucleotide
What is a nucleotide composed of
A pentose sugar, a phosphate group, a nitrogenous base
What are the two types of bases
Purine and pyrimidine
Purines
Have a double ring structure (adenine and guanine)
