DNA and Genes Overview

DNA is a double-stranded helix made of polynucleotides.

DNA is the genetic material that makes up genes, which code for traits.

Four types of nucleotides make up DNA.

Genome size (amount of DNA) doesn't always predict the complexity of a species.

Early 1900s scientists debated if DNA or protein was the genetic material; by 1952 experiments with bacteria confirmed DNA as the genetic material.

Viruses, like the porcine circovirus, have a small genome size.

Bacteria, like Mycoplasma genitalium, can have a large genome size.

A relationship between genome size to complex cells doesn't exist in eukaryotes.

The process of using the genetic information in a gene to create a specific trait or characteristic.

The process of creating RNA from a DNA template.

The process of building a protein from an RNA molecule.

The observable characteristic or trait of an organism.

The twisted, ladder-like shape of a DNA molecule, formed by two strands of polynucleotides.

The specific way in which nitrogenous bases in DNA pair up (A with T, and G with C).

Messenger RNA; carries genetic instructions from DNA to the ribosomes for protein synthesis.

A region of DNA that controls whether a gene is transcribed.

Sections of DNA that do not code for proteins or functional RNA.

Genetic material of a prokaryotic organism, typically a single circular chromosome.

Genetic material of a eukaryotic organism, containing a large amount of noncoding DNA.

Noncoding DNA that separates genes.

DNA sequences that can move within a chromosome or between chromosomes.

Noncoding DNA sequences within a gene.

Proteins that DNA wraps around to organize chromosomes.

The process of compressing DNA into chromosomes for cell division.

DNA replication where each new DNA molecule contains one original (template) strand and one new strand.

Enzyme that adds nucleotides to create a new DNA strand, using the original strand as a template; also proofreads for accuracy.

Y-shaped region where the DNA double helix unwinds and separates during replication.

Specific location on a DNA molecule where DNA replication begins.

DNA strand synthesized continuously in the 5' to 3' direction during replication, in the direction of the replication fork.

DNA strand synthesized discontinuously in short fragments called Okazaki fragments, in the opposite direction of the replication fork.

Short, discontinuous DNA fragments synthesized on the lagging strand during replication.

Enzyme that joins Okazaki fragments together to form a continuous lagging strand.

Each new DNA molecule consists of one original strand and one new strand.

On average, prokaryotes have more genes than single-celled eukaryotes.

Proofreading by DNA polymerase and DNA repair systems prevent mutations.

Human genome size is not a direct measure of complexity compared to other species.

DNA repair is crucial for maintaining DNA integrity, not limited to replication.

Recognition, removal, and replacement of damaged DNA.

Humans have more DNA, but not many more genes than E. coli.

Gene expression is the process of a gene producing a phenotype; usually via mRNA to protein.

All cells in an organism share the same DNA, meaning, the genome is identical.

Non-coding DNA regulates gene expression, has structure, and connects genes.

Different cells express different subsets of genes, even with the same genome.

The 30-nanometer fiber is a more compact form than beads-on-a-string.

The complementary strand of a DNA sequence has the opposite base pairings: A with T, and C with G.

Reduced entanglement risk during cell division.

Genes are expressed only when and where needed.

Different sequences of nucleotides result in different genes carrying unique information.