Molecular biologyMolecular biology məˈlɛkjʊlər is the study of chemical and physical structure of biological macromolecules. It is a branch of biology that seeks to understand the molecular basis of biological activity in and between cells, including biomolecular synthesis, modification, mechanisms, and interactions. Molecular biology was first described as an approach focused on the underpinnings of biological phenomena—uncovering the structures of biological molecules as well as their interactions, and how these interactions explain observations of classical biology.
Transcription factorIn molecular biology, a transcription factor (TF) (or sequence-specific DNA-binding factor) is a protein that controls the rate of transcription of genetic information from DNA to messenger RNA, by binding to a specific DNA sequence. The function of TFs is to regulate—turn on and off—genes in order to make sure that they are expressed in the desired cells at the right time and in the right amount throughout the life of the cell and the organism.
GastrulationGastrulation is the stage in the early embryonic development of most animals, during which the blastula (a single-layered hollow sphere of cells), or in mammals the blastocyst is reorganized into a multilayered structure known as the gastrula. Before gastrulation, the embryo is a continuous epithelial sheet of cells; by the end of gastrulation, the embryo has begun differentiation to establish distinct cell lineages, set up the basic axes of the body (e.g.
Arabidopsis thalianaArabidopsis thaliana, the thale cress, mouse-ear cress or arabidopsis, is a small plant from the mustard family (Brassicaceae), native to Eurasia and Africa. Commonly found along the shoulders of roads and in disturbed land, it is generally considered a weed. A winter annual with a relatively short lifecycle, A. thaliana is a popular model organism in plant biology and genetics. For a complex multicellular eukaryote, A. thaliana has a relatively small genome of around 135 megabase pairs.
Caenorhabditis elegansCaenorhabditis elegans (ˌsiːnoʊræbˈdaɪtəs_ˈɛləɡæns) is a free-living transparent nematode about 1 mm in length that lives in temperate soil environments. It is the type species of its genus. The name is a blend of the Greek caeno- (recent), rhabditis (rod-like) and Latin elegans (elegant). In 1900, Maupas initially named it Rhabditides elegans. Osche placed it in the subgenus Caenorhabditis in 1952, and in 1955, Dougherty raised Caenorhabditis to the status of genus. C.
Cleavage (embryo)In embryology, cleavage is the division of cells in the early development of the embryo, following fertilization. The zygotes of many species undergo rapid cell cycles with no significant overall growth, producing a cluster of cells the same size as the original zygote. The different cells derived from cleavage are called blastomeres and form a compact mass called the morula. Cleavage ends with the formation of the blastula, or of the blastocyst in mammals.
Germ cellA germ cell is any cell that gives rise to the gametes of an organism that reproduces sexually. In many animals, the germ cells originate in the primitive streak and migrate via the gut of an embryo to the developing gonads. There, they undergo meiosis, followed by cellular differentiation into mature gametes, either eggs or sperm. Unlike animals, plants do not have germ cells designated in early development. Instead, germ cells can arise from somatic cells in the adult, such as the floral meristem of flowering plants.
Drosophila melanogasterDrosophila melanogaster is a species of fly (the taxonomic order Diptera) in the family Drosophilidae. The species is often referred to as the fruit fly or lesser fruit fly, or less commonly the "vinegar fly" or "pomace fly". Starting with Charles W. Woodworth's 1901 proposal of the use of this species as a model organism, D. melanogaster continues to be widely used for biological research in genetics, physiology, microbial pathogenesis, and life history evolution.
Regeneration (biology)In biology, regeneration is the process of renewal, restoration, and tissue growth that makes genomes, cells, organisms, and ecosystems resilient to natural fluctuations or events that cause disturbance or damage. Every species is capable of regeneration, from bacteria to humans. Regeneration can either be complete where the new tissue is the same as the lost tissue, or incomplete after which the necrotic tissue becomes fibrosis.
MetamorphosisMetamorphosis is a biological process by which an animal physically develops including birth transformation or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some insects, fish, amphibians, mollusks, crustaceans, cnidarians, echinoderms, and tunicates undergo metamorphosis, which is often accompanied by a change of nutrition source or behavior.
