Genetics 3500: Chapter 10

The 3 characteristics that are key features of genetic material.

1. It must periodically mutate to generate variation. 2. It must be able to replicate and transmit to progeny. 3. It must be able to store and express information.

Identify the key structural features of a DNA molecule.

1. The backbone of DNA is made of a sugar and a phosphate molecule. 2. DNA bases are always paired purine with pyrimidine. 3. DNA strands are antiparallel and include a 5\' end and a 3\' end.

What relations will be found in the percentages of bases of a double-stranded DNA molecule?

A/T = G/C A+G = C+T (A+G) / (C+T) = 1.0

Describe purines and pyrimidines in DNA molecules.

Purines - type of nitrogenous base in DNA and RNA (Adenine and Guanine). Consist of a two-ring structure and for H-bonds with pyrimidines Pyrimidines - Cytosine, Thymine, and Uracil

DNA has unique properties that allow it to accurately retain genetic information, even after multiple rounds of replication. One aspect of DNA that allows it to accurately store genetic information is the base pairing from Chargaff's first rule of the four nucleotide bases. If the A content of a DNA molecule is 22%, what are the percentages of the remaining bases?

T = 22% G = 28% C = 28%

What contribution did James Watson and Francis Crick make to our understanding of DNA?

They pieced together the available evidence and modeled the structure of DNA.

What is the key feature of DNA that allows it to be copied?

complementary base pairing