A Closer Look at DNA: DNA Structure and Replication

These flashcards cover key concepts related to the structure and replication of DNA, including historical figures, DNA components, key processes, and important findings from molecular biology.

James Watson and Francis Crick determined the structure of DNA in __.

1953.

Rosalind Franklin was known for her work in __.

X-ray crystallography.

The building blocks of DNA are called __.

Nucleotides.

Nucleotides consist of a phosphate group, __, and a nitrogenous base.

Pentose sugar.

The two strands of DNA form a __ structure.

double helix.

The backbone of the DNA ladder is formed by __ and phosphate groups.

sugar.

In DNA, purines include guanine (G) and __.

adenine (A).

Pyrimidines in DNA include cytosine (C) and __.

thymine (T).

DNA strands run in __ directions.

antiparallel.

Each human cell has __ DNA molecules in its nucleus.

46.

The entire human genome includes approximately __ chemical nucleotide bases.

3164.7 million.

The largest known human gene is __, which consists of 2.4 million bases.

dystrophin.

The total estimated number of genes in humans is around __.

30,000.

Almost all human nucleotide bases are identical, with __% being the same across all people.

99.9.

Less than __% of the human genome codes for proteins.

2.

The order of A's, T's, C's, and G's determines an organism's __.

identity.

DNA replication models include semiconservative, __, and dispersive.

conservative.

Newly made strands during DNA replication are known as __ strands.

daughter.

DNA replication begins at __ points.

origin.

During replication, the original strands are referred to as __ strands.

parental.

The new nucleotides must follow the __ rule during DNA replication.

A-T/G-C.

RNA primers are synthesized by __ to initiate DNA replication.

DNA primase.

DNA ligase is responsible for __ segments during replication.

joining.

DNA helicase functions to __ the DNA strands during replication.

separate.

Telomeres consist of repeating nucleotide sequences, such as __.

TTAGGG.

The enzyme that compensates for the shortening of DNA during replication is called __.

telomerase.