Cells are the smallest and basic units of life, whether it is a single cell that forms the entire organism, e.g., in a bacterium, or trillions of them, ...

The “tree of life” describes the evolution of life and the evolutionary relationships between organisms. The root of the tree is the common ...

Prokaryotes are small unicellular organisms that include the domains — Archaea and Bacteria. Bacteria include many common microorganisms, such as ...

One of the distinguishing features of eukaryotic cells is that they contain membrane-bound organelles, such as the nucleus and mitochondria, that carry ...

The endosymbiont theory is the most widely accepted theory of eukaryotic evolution; however, its progression is still somewhat debated. According to the ...

Animal and plant cells not only differ in their structure, function, and mode of nutrition but also in how they reproduce, specialize, and organize into ...

The cytoplasm consists of organelles and a framework of protein scaffolds called the cytoskeleton suspended in an aqueous solution, the cytosol. The ...

The nucleus is a membrane-bound organelle that acts as a control center in a eukaryotic cell. It contains chromosomal DNA, which controls gene expression ...

Deoxyribonucleic acid, or DNA, is the genetic material responsible for passing traits from generation to generation in all organisms and most viruses. DNA ...

The central dogma explains the flow of genetic information from DNA nucleotides to the amino acid sequence of proteins. RNA is the Missing Link Between ...

Mutations are changes in the sequence of DNA. These changes can occur spontaneously or they can be induced by exposure to environmental factors. Mutations ...

While every living organism has a genome of some kind (be it RNA, or DNA), there is considerable variation in the sizes of these blueprints. One major ...

Gene families consist of groups of genes proposed to have originated from a common ancestor. Typically these arise through events in which a gene or genes ...

The genomes of eukaryotes are punctuated by long stretches of sequence which do not code for proteins or RNAs. Although some of these regions do contain ...

Genetic transfer occurs when genetic information is passed from one organism to another. It occurs via two mechanisms: vertical gene transfer and ...