The central dogma of molecular biology was first enunciated by Francis Crick in 1958 and re-stated in a Nature paper published in 1970. The precise definition is: The central dogma of molecular biology deals with the detailed residue-by-residue transfer of sequential information. It states that such information cannot be transferred from protein to either protein or nucleic acid. In other words, ...

Including:

• Central dogma of molecular biology - Transcription
• Central dogma of molecular biology - Splicing
• Central dogma of molecular biology - Translation
• Central dogma of molecular biology - Replication
• Central dogma of molecular biology - Alterations to the central dogma
• Central dogma of molecular biology - Flow from RNA to DNA
• Central dogma of molecular biology - Viruses with RNA-only genomes
• Central dogma of molecular biology - Prions
• Central dogma of molecular biology - Criticisms of the use of the central dogma as a research strategy

Read more here: » Central dogma of molecular biology: Encyclopedia - Central dogma of molecular biology

The cell structure of prokaryotes differs greatly from eukaryotes in many ways. The defining characteristic is, of course, the absence of a nucleus or nuclear envelope. Prokaryotes also were previously considered to lack cytoskeletons and do lack membrane-bound cell compartments such as vacuoles, endoplasmic reticulum, mitochondria and chloroplasts. In eukaryotes, the latter two perform various metabolic processes and are believed to have been derived from endosymbiotic bacteria. In prokaryotes similar processes occur across the cell membran ...

See also:

Prokaryote, Prokaryote - Structure, Prokaryote - Environment, Prokaryote - Evolution of prokaryotes

Read more here: » Prokaryote: Encyclopedia II - Prokaryote - Structure

Saccharomyces cerevisiae is a species of budding yeast. It is perhaps the most relevant yeast for mankind, both for its use since ancient times in baking and brewing, and for being one of the most intensively studied eukaryotic model organisms in molecular and cell biology, much like Escherichia coli as the model prokaryote. It is the microorganism behind the most common type of fermentation. Saccharomyces cerevisiae cells are round to ovoid, 5-10 Micrometres in ...

Including:

• Saccharomyces cerevisiae - Lifecycle
• Saccharomyces cerevisiae - In Science
• Saccharomyces cerevisiae - Yeast Mating

Read more here: » Saccharomyces cerevisiae: Encyclopedia - Saccharomyces cerevisiae

Astrosociobiology (also referred to as exosociobiology and xenosociology) is the speculative scientific study of extraterrestrial civilizations and their possible social characteristics and developmental tendencies. The field involves the convergence of astrobiology, sociobiology and evolutionary biology. Hypothesized comparisons between human civilizations and those of extraterrestrials are frequently posited, placing the human situation in the same context as other extraterrestrial intelligences. Whenever possible, ast ...

Including:

• Astrosociobiology - Methodologies
• Astrosociobiology - Assumptions
• Astrosociobiology - Possible extraterrestrial characteristics
• Astrosociobiology - Civilization types
• Astrosociobiology - Related sites
• Astrosociobiology - Astrosociobiologists

Read more here: » Astrosociobiology: Encyclopedia - Astrosociobiology

Main article Evolution of prokaryotes It is generally accepted that the first living cells were some form of prokaryote. Fossilized prokaryotes 3.5 billion years old have been discovered, and prokaryotes are perhaps the most successful and abundant organism even today. In contrast the eukaryote only appeared approximately 1.5 billion years ago. While earth is the only known place where prokaryotes exist, some have suggested structures within a Martian meteorite should be interpreted ...

See also:

Prokaryote, Prokaryote - Structure, Prokaryote - Environment, Prokaryote - Evolution of prokaryotes

Read more here: » Prokaryote: Encyclopedia II - Prokaryote - Evolution of prokaryotes

An embryo (Greek: έμβρυον) is a diploid eukaryote in its earliest stage of development. In organisms that reproduce sexually, once a sperm fertilizes an egg cell, the result is a cell called the zygote that has all the DNA of two parents. In plants, animals, and some protists, the zygote will begin to divide by mitosis to produce a multicellular organism. The term embryo refers to the early stages of this development, after the zygote has divided at least once, but before the process has completed to produc ...

Including:

• Embryo - External link

Read more here: » Embryo: Encyclopedia - Embryo

It is generally accepted that the first living cells were some form of prokaryote. Fossilized prokaryotes 3.5 billion years old have been discovered, and prokaryotes are perhaps the most successful and abundant organism even today. In contrast the eukaryote only appeared approximately 1.5 billion years ago. While earth is the only known place where prokaryotes exist, some have suggested structures within a Martian meteorite should be interpreted as fossil prokaryotes, but this is extremely doubtful. Prokaryotes diversified greatly thr ...

See also:

Prokaryote, Prokaryote - Structure, Prokaryote - Environment, Prokaryote - Evolution of prokaryotes

Read more here: » Prokaryote: Encyclopedia II - Prokaryote - Evolution of prokaryotes

There are two types of geyser; Fountain geysers erupt from pools of water, typically in a series of intense, even violent, bursts; and cone geysers which erupt from cones or mounds of siliceous sinter (also known as geyserite), usually in steady jets that last anywhere from a few seconds to several minutes. Old Faithful, perhaps the best-known geyser at Yellowstone National Park, is an example of a cone geyser. The intense transient forces inside erupting geysers are the main reason for their rarity. There are many volca ...

See also:

Geyser, Geyser - Eruptions, Geyser - Types of geyser, Geyser - Numbers and distribution, Geyser - Misnamed geysers, Geyser - Geysers on Triton

Read more here: » Geyser: Encyclopedia II - Geyser - Types of geyser

In his paper "Versuche über Pflanzenhybriden" ("Experiments in Plant Hybridization"), presented in 1865 to the Brunn Natural History Society, Gregor Mendel traced the inheritance patterns of certain traits in pea plants and showed that they could be described mathematically. Although not all features show these patterns of Mendelian inheritance, his work suggested the utility of the application of statistics to the stu ...

See also:

Genetics, Genetics - History, Genetics - Timeline of notable discoveries, Genetics - Areas of genetics, Genetics - Classical genetics, Genetics - Behavioral genetics, Genetics - Clinical genetics, Genetics - Molecular genetics, Genetics - Population quantitative and ecological genetics, Genetics - Genomics, Genetics - Closely-related fields, Genetics - Publications

Read more here: » Genetics: Encyclopedia II - Genetics - History

The first description on this class of bacteria appeared 1963 in a publication of the Istituto di Microbiologia of University of Pavia written by the MD, Salvatore Bellini.While observing occasionally bog sediments under his microscope, he noticed a group of bacteria which evidently oriented themselves in unique direction and soon realised that these microrganisms were following the direction of North Pole and they denominated "magnetosensitive bacteria". Successively appeared 1975 in issue of Science, an essay written by the microbio ...

See also:

Magnetotactic bacteria, Magnetotactic bacteria - Introduction, Magnetotactic bacteria - Biology, Magnetotactic bacteria - Magnetism, Magnetotactic bacteria - Magnetosomes, Magnetotactic bacteria - Membrane and proteins, Magnetotactic bacteria - Biomineralisation, Magnetotactic bacteria - Applications, Magnetotactic bacteria - Biotechnology, Magnetotactic bacteria - Medicine, Magnetotactic bacteria - Bibliography

Read more here: » Magnetotactic bacteria: Encyclopedia II - Magnetotactic bacteria - Introduction

DNA barcoding - Identification of Birds. In an effort to find a correspondence between traditional species boundaries established by taxonomy and those inferred by DNA barcoding, Hebert and co-workers sequenced DNA barcodes of 260 of the 667 bird species that breed in North America (Hebert et al. 2004a). They found that every single one of the 260 species had a different COI sequence. 130 species were represented by two or more specimens, in all of these species. COI sequences were either identical or were ...

See also:

DNA barcoding, DNA barcoding - Origin, DNA barcoding - Case Studies, DNA barcoding - Identification of Birds, DNA barcoding - Delimiting Cryptic Species, DNA barcoding - Identifying Flowering Plants, DNA barcoding - Cataloguing Ancient Life, DNA barcoding - Criticisms

Read more here: » DNA barcoding: Encyclopedia II - DNA barcoding - Case Studies

In 1865 an Austrian monk Gregor Mendel first traced inheritance patterns of certain traits in pea plants and showed that they obeyed simple statistical rules. Although not all features show these patterns of Mendelian inheritance, his work acted as a proof that application of statistics to inheritance could be highly useful. Since that time many more complex forms of inheritance have been demonstrated. From his statistical analysis Mendel defined a concept that he described as an allele, which was the fundamental unit of heredi ...

See also:

History of genetics, History of genetics - Pre-Mendelian ideas on heredity, History of genetics - Mendel, History of genetics - Post-Mendel pre-re-discovery, History of genetics - Classical genetics, History of genetics - The DNA era, History of genetics - The genomics era

Read more here: » History of genetics: Encyclopedia II - History of genetics - Mendel

Genomics appeared in the 1980s and took off in the 1990s with the initiation of genome projects for several species. The related field of genetics is the study of genes and their role in inheritance. The first genome to be sequenced in its entirety was that of bacteriophage Φ-X174; (5,368 kb) in 1980. The first free-living organism to be sequenced was that of Haemophilus influenzae (1.8Mb) in 1995, and since then genomes are being sequenced at a rapid pace. A rough draft of the human genome was completed by the Human Genome Project in early 2001 amid much fanfare. Genomics - The growth of the omics. See also:

Genomics, Genomics - History, Genomics - The growth of the omics, Genomics - Comparative genomics, Genomics - Genetic similarity

Read more here: » Genomics: Encyclopedia II - Genomics - History

Mitochondrial DNA (mtDNA) is present in mitochondria as a circular molecule and in most species codes for 13 or 14 proteins involved in the electron transfer chain, 2 rRNA subunits and 22 tRNA molecules (all necessary for protein synthesis). The number of proteins involved in the electron transfer chain is much larger than 13 or 14, but the remainder is in fact coded by the nuclear DNA. In total, the mitochondrion hosts about 3000 proteins, but only about 37 of them are coded on the mitochondrial DNA. Most of the 3000 genes are involv ...

See also:

Mitochondrial genetics, Mitochondrial genetics - The mitochondrial genome, Mitochondrial genetics - Inheritance patterns, Mitochondrial genetics - The Genetic Code, Mitochondrial genetics - Mitochondrial Replication Repair Transcription and Translation, Mitochondrial genetics - Chromosomally Mediated mtDNA Replication Errors, Mitochondrial genetics - Relevance, Mitochondrial genetics - Mitochondrial Membrane Complexes, Mitochondrial genetics - Mitochondrial Diseases, Mitochondrial genetics - Sources, Mitochondrial genetics - Notes

Read more here: » Mitochondrial genetics: Encyclopedia II - Mitochondrial genetics - The mitochondrial genome

Given these assumptions, astrosociobiologists attempt to make predictions about those characteristics that may be common to all extraterrestrial societies. For example, based on human experience, astrosociobiologists conclude very broadly that all civilizations go through similar developmental stages, including agrarian culture, industrialization, democratization, globalization, and an information age (this being said, it's still not an absolute certainty that democracy is here to stay, nor that ETIs are able to maintain it either; totalitar ...

See also:

Astrosociobiology, Astrosociobiology - Methodologies, Astrosociobiology - Assumptions, Astrosociobiology - Possible extraterrestrial characteristics, Astrosociobiology - Civilization types, Astrosociobiology - Related sites, Astrosociobiology - Astrosociobiologists

Read more here: » Astrosociobiology: Encyclopedia II - Astrosociobiology - Possible extraterrestrial characteristics

In his paper "Versuche über Pflanzenhybriden" ("Experiments in Plant Hybridization"), presented in 1865 to the Brunn Natural History Society, Gregor Mendel traced the inheritance patterns of certain traits in pea plants and showed that they could be described mathematically. Although not all features show these patterns of Mendelian inheritance, his work suggested the utility of the application of statistics to the study of inheritance. Since that time many more complex forms of ...

See also:

Genetics, Genetics - History, Genetics - Timeline of notable discoveries, Genetics - Areas of genetics, Genetics - Classical genetics, Genetics - Behavioral genetics, Genetics - Clinical genetics, Genetics - Molecular genetics, Genetics - Population quantitative and ecological genetics, Genetics - Genomics, Genetics - Closely-related fields, Genetics - Publications

Read more here: » Genetics: Encyclopedia II - Genetics - History

In his 1970 paper on the subject, Crick pointed out that the central dogma, while useful as a theory to guide experiment, was not to be taken as dogma: "Although the details of the classification proposed here are plausible, our knowledge of molecular biology, even in one cell -- let alone for all the organisms in nature -- is still far too incomplete to allow us to assert dogmatically that it is correct." - Francis Crick Since the 1970 paper, a number of facts have emerged suggesting the need for it to be restated:< ...

See also:

Central dogma of molecular biology, Central dogma of molecular biology - Transcription, Central dogma of molecular biology - Splicing, Central dogma of molecular biology - Translation, Central dogma of molecular biology - Replication, Central dogma of molecular biology - Alterations to the central dogma, Central dogma of molecular biology - Flow from RNA to DNA, Central dogma of molecular biology - Viruses with RNA-only genomes, Central dogma of molecular biology - Prions, Central dogma of molecular biology - Criticisms of the use of the central dogma as a research strategy

Read more here: » Central dogma of molecular biology: Encyclopedia II - Central dogma of molecular biology - Alterations to the central dogma

The cell type is dependent on a single gene locus, called MAT, which regulates the expression of a set of genes. MAT has three segemts, in order 5' to 3', W, X, Y and Z. THe Y sequence is variable, and there are two different versions: Ya (642 bp) and Yα (747 bp), corresponding to MATa and MATα. MATa produces a single transcript, a1 and is active in a type cells. MATα produces two transcripts, α1 and α2 and is active in ...

See also:

Mating of yeast, Mating of yeast - The life cycle of yeast, Mating of yeast - The importance of a and α mating types, Mating of yeast - Determining cell type, Mating of yeast - a and α specific promoters, Mating of yeast - a type cells, Mating of yeast - α type cells, Mating of yeast - Diploid type cells, Mating of yeast - Cell type switching, Mating of yeast - The cassette principle, Mating of yeast - The cassette mechanism, Mating of yeast - Switching specificity to mother cells

Read more here: » Mating of yeast: Encyclopedia II - Mating of yeast - Determining cell type

In plants, plastids may differentiate into several forms, depending upon which function they need to play in the cell. Undifferentiated plastids (proplastids) may develop into any of the following plastids: Amyloplasts: for starch storage Chloroplasts: for photosynthesis Etioplasts: chloroplasts that have not been exposed to light Elaioplasts: for storing fat Chromoplasts: for pigment synthesis and storage

Plastids are thought to have originated from endosymbiotic cyanobacteria. Due to a split-up into three evolutionary lineages, the plastids are named differently: chloroplasts in green algae and plants, rhodoplasts in red algae and cyanelles in the glaucophytes. The plastids differ by their pigmentation, but also in ultrastructure. The chloroplasts e.g. have lost all phycobilisomes, the light harvesting complexes found in cyanobacteria, red algae and glaucophytes, but - only in plants and in closely related green algae - contain stroma and gr ...

See also:

Plastid, Plastid - Plastids in plants, Plastid - Plastids in algae, Plastid - Origin of plastids, Plastid - Sources

Read more here: » Plastid: Encyclopedia II - Plastid - Origin of plastids