DNA Lab Report What is DNA? What do the letters stand for? What is it composed of? Where is it found? What is it shaped like? Answer in full sentences. DNA Timeline DNA has been researched by scientists for over 100 years, even before some knew what it was. From determining the complementary base pairs to the iconic double helix to using DNA to decode the human genome, DNA has had many milestones. Using information from the text and online research, arrange these DNA milestones in chronological order by putting a number from 1 (the earliest) to 11 (the most recent) next to each milestone. The Human Genome project was completed. Linus Pauling proposed the triple helix. Mendel published his study of pea plants to determine the laws of inheritance. Hershey and Chase confirmed that DNA is genetic material using their famous density gradient centrifuge technique. Matthew Stanley Meselson and Franklin William Stahl proved semi conservative replication, showing how DNA unzips to split into two pieces before replicating. Rosalind Franklin used x-ray diffraction to determine the structure of DNA. She proposed a helical structure with the phosphate groups on the outside. Thomas Hunt Morgan published findings from an examination of genetics of fruit flies and determines chromosomes are the basis for heredity. Arthur Kornberg discovered DNA polymerase, the molecule that is responsible for assembling parts of DNA during replication. Reverse Transcriptase was discovered by David Baltimore and Howard Martin Temin. Marshall Warren Nirenberg deciphered the genetic code Alec Jeffreys developed DNA fingerprinting.

Explanation:

What is DNA?

DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms. Nearly every cell in a person’s body has the same DNA. Most DNA is located in the cell nucleus (where it is called nuclear DNA), but a small amount of DNA can also be found in the mitochondria (where it is called mitochondrial DNA or mtDNA). Mitochondria are structures within cells that convert the energy from food into a form that cells can use.

The information in DNA is stored as a code made up of four chemical bases: adenine (A), guanine (G), cytosine (C), and thymine (T). Human DNA consists of about 3 billion bases, and more than 99 percent of those bases are the same in all people. The order, or sequence, of these bases determines the information available for building and maintaining an organism, similar to the way in which letters of the alphabet appear in a certain order to form words and sentences.

DNA bases pair up with each other, A with T and C with G, to form units called base pairs. Each base is also attached to a sugar molecule and a phosphate molecule. Together, a base, sugar, and phosphate are called a nucleotide. Nucleotides are arranged in two long strands that form a spiral called a double helix. The structure of the double helix is somewhat like a ladder, with the base pairs forming the ladder’s rungs and the sugar and phosphate molecules forming the vertical sidepieces of the ladder.

An important property of DNA is that it can replicate, or make copies of itself. Each strand of DNA in the double helix can serve as a pattern for duplicating the sequence of bases. This is critical when cells divide because each new cell needs to have an exact copy of the DNA present in the old cell.

the electromagnetic energy from the sun arrives in the form of visible and invisible light.