BIOLOGY Chapter 12 DNA Quiz

DNA resembles a twisted ladder, with nitrogen bases forming the rungs and deoxyribose sugars along with phosphates making up the sides.
A nucleotide, the monomer of DNA, consists of one deoxyribose sugar, one phosphate group, and one nitrogen base.

Four nitrogen bases in DNA are adenine, thymine, cytosine, and guanine.
Complementary base pairs are adenine paired with thymine, and cytosine paired with guanine.
Chargaff's Rule states that the amount of adenine equals thymine and the amount of guanine equals cytosine in DNA.

DNA replication is the process of duplicating DNA before cell division and occurs in the nucleus of eukaryotic cells and in the cytoplasm of prokaryotic cells.
It takes place during the Synthesis phase of interphase to produce genetically identical cells.
In eukaryotic cells, replication begins at multiple points, known as origins of replication, allowing for faster replication.

The process starts with DNA ready for copying.
Helicase unwinds the DNA by breaking hydrogen bonds between bases.
DNA polymerase uses each strand as a template to add complementary bases.
DNA polymerase also proofreads the new strands to correct any errors, resulting in two new double helices.

Frederick Griffith demonstrated genetic transfer through transformation by injecting different bacterial strains into mice.
Oswald Avery identified DNA as the molecule responsible for storing and transmitting genetic information, categorizing it as a nucleic acid.
Hershey and Chase used bacteriophages to confirm that DNA is the nucleic acid responsible for genetic information, not proteins.
Erwin Chargaff established rules for base pairing and the ratio of bases in DNA.
Rosalind Franklin and Maurice Wilkens employed X-ray diffraction to reveal DNA's helical shape.
James Watson and Francis Crick confirmed DNA's structure as a double helix, with complementary nitrogen base pairs bonded via hydrogen interactions, assembled between deoxyribose sugars and phosphate groups.