Sentences with phrase «celled eukaryotes»

Formed by the merger of fat - eating mitochondria with glucose - eating bacteria, single - celled eukaryotes had to regulate their various metabolic pathways to keep themselves from becoming too fatty or too lean (and to control the urge of mitochondria to eat their hosts!).

Bacterial Gene Numbers Vary from Approximately 500 to 8000 and Overlap Those of Single - Celled Eukaryotes The bacterial genome projects already provide excellent estimates for the number and types of protein and RNA molecules made by free living prokaryotes (Table 1).

Protists — a catch - all word, for the diverse array of single - celled eukaryotes found in virtually all moist environments — have received far less attention, despite being ubiquitous, ecologically important, and also medically significant.

To him, one - celled eukaryotes are Serengeti charismatic, just smaller.

On further examination, it turned out that the black specks are a type of organelle — called an acidocalcisome — that is also found in certain single - celled eukaryotes.

To find clues, she has trained her sights on choanoflagellates — a group of single - celled eukaryotes thought to be the closest living relatives of animals.

Boule homologs are also absent in other single - cell eukaryotes and in plants, including Schizosaccharomyces pombe, Dictyostelium discoideum and Arabidopsis thaliana.

Not exact matches

«In its 4.6 billion years circling the sun, the Earth has harbored an increasing diversity of life forms: for the last 3.6 billion years, simple cells (prokaryotes); for the last 3.4 billion years, cyanobacteria performing ph - otosynthesis; for the last 2 billion years, complex cells (eukaryotes); for the last 1 billion years, multicellular life; for the last 600 million years, simple animals; for the last 550 million years, bilaterians, animals with a front and a back; for the last 500 million years, fish and proto - amphibians; for the last 475 million years, land plants; for the last 400 million years, insects and seeds; for the last 360 million years, amphibians; for the last 300 million years, reptiles; for the last 200 million years, mammals; for the last 150 million years, birds; for the last 130 million years, flowers; for the last 60 million years, the primates, for the last 20 million years, the family H - ominidae (great apes); for the last 2.5 million years, the genus H - omo (human predecessors); for the last 200,000 years, anatomically modern humans.»

for the last 3.6 billion years, simple cells (prokaryotes); for the last 3.4 billion years, cyanobacteria performing photosynthesis; for the last 2 billion years, complex cells (eukaryotes); for the last 1 billion years, multicellular life; for the last 600 million years, simple animals; for the last 550 million years, bilaterians, animals with a front and a back; for the last 500 million years, fish and proto - amphibians; for the last 475 million years, land plants; for the last 400 million years, insects and seeds; for the last 360 million years, amphibians; for the last 300 million years, reptiles; for the last 200 million years, ma - mmals; for the last 150 million years, birds; for the last 130 million years, flowers; for the last 60 million years, the primates, for the last 20 million years, the family H - ominidae (great apes); for the last 2.5 million years, the genus H - omo (human predecessors); for the last 200,000 years, anatomically modern humans.

In eukaryotes such as animals and plants, DNA is stored inside the cell nucleus, while in prokaryotes such as bacteria and archaea, the DNA is in the cell's cytoplasm.

«By studying its genome, we found that Loki represents an intermediate form in - between the simple cells of microbes, and the complex cell types of eukaryotes,» says Thijs Ettema.

Despite that archaeal cells were simple and small like bacteria, researchers found that Archaea were more closely related to organisms with complex cell types, a group collectively known as «eukaryotes».

The advent of the nucleus — which differentiates eukaryotes (organisms whose cells contain a true nucleus), including humans, from prokaryotes, such as bacteria — can not be satisfactorily explained solely by the gradual adaptation of prokaryotic cells until they became eukaryotic.

This observation has puzzled scientists for decades: How could the complex cell types from eukaryotes have emerged from the simple cells of Archaea?

At some point, Martin speculates, the bacterium gave the archaean a gene for membrane synthesis, leading to a bubbling up of membrane within the host cell, something like what happens when modern eukaryotes divide and then reform their nucleus from membrane pieces grown inside them.

Second, eukaryotes contain various organelles, internal compartments partitioned off from the rest of the cell by membranes.

Finding the answer would fill a major gap in the history of eukaryotes (literally, cells with a «true nucleus»), which in the space of two billion years have populated the world with everything from singled - celled amoeba and plankton to pine trees, scientists and, of course, elephants.

«The heart of the problem is that the logic of the eukaryote is very different from the logic of the prokaryotic cell, yet there has been a huge input from the prokaryote to the eukaryote,» Hartman says.

Biochemist Radhey Gupta of McMaster University in Canada proposes that a bacterium and an archaean fused to form the first eukaryote, based on his analysis of a pair of slow - changing genes found in what may be one of the oldest cells with a nucleus, Giardia lamblia.

The resulting mergers yielded the compound cells known as eukaryotes, which in turn gave rise to all the rest — the protoctists, fungi, plants, and animals, including humans.

These single - celled organisms, unlike eukaryotes, lack nuclei and other organelles.

Eukaryotes are the most structurally complex known cell type, and by definition are in part organized by smaller interior compartments, that are themselves enclosed by lipid membranes that resemble the outermost cell membrane.

Biologists have proposed that this swallowing event, perhaps 1.8 billion years ago, led to complex cells with membrane - wrapped organelles, the hallmark of all eukaryotes from amoebas to zebras.

This is the first eukaryote — organisms, like plants and animals, whose cells contain distinct nuclei — found without the machinery of mitochondria.

It also suggests that cell life could have emerged with a far greater variety of pre-cellular forms than those conventionally considered, as the new giant virus has almost no equivalent among the three recognized domains of cellular life, namely eukaryota (or eukaryotes), eubacteria, and archaea.

They live inside their host's cells and have highly specialized features: They are only able to reproduce inside the host's cells, they have the smallest known genome of all organisms with a cell nucleus (eukaryotes) and they posses no mitochondria of their own (the cell's power plant).

Work by Gonzalo Vidal of the University of Uppsala in Sweden indicates that single - celled planktonic eukaryotes certainly date back to 1.7 billion years B.P. and very likely to at least 2.2 billion years B.P..

Even more notable, Loki has genes that code for proteins involved in phagocytosis, the process by which one cell can swallow another — and widely believed to be the way eukaryotes acquired mitochondria, a cell's power source.

Meiosis is essential for sexual reproduction and therefore occurs in all eukaryotes (including single - celled organisms) that reproduce sexually.

(Eukaryotes are all organisms with cells that contain a nucleus, from microbes to plants to vertebrates.

This group's achievement shows the possibility to clarify the mechanism of human tumor formation, especially the molecular mechanism responsible for in the initial stage of cell cancerization due to DNA damaged by radiation in the initial stage, by using the model of budding yeast, a primitive eukaryote.

Most biologists typically recognize three official branches of life: the eukaryotes, which are organisms whose cells have a nucleus; bacteria, the single - celled organisms that may or may not possess a nucleus; and archaea, an ancient line of microbes without nuclei that may make up as much as a third of all life on Earth (See «Will the Methane Bubble Burst?»

If so, then modern eukaryote cells could be the product of geologically rare conditions.»

Cells from animals, plants and fungi, which make up the eukaryotes, are much more sophisticated.

Though little is known about Loki, scientists hope that it will help to resolve one of biology's biggest mysteries: how life transformed from simple single - celled organisms to the menagerie of complex life known as eukaryotes — a category that includes everything from yeast to azaleas to elephants.

But no detectable intermediates between ancient, single - celled life and early eukaryotes exist, making it nearly impossible to reconstruct the order of evolutionary events.

«If we could turn back the clock and peer inside this cell, would its cellular organization have been like that of an archaeal cell or more eukaryote - like?»

Autophagy is the «self - eating» process of consuming the portion of intracellular proteins in the cells of eukaryotes such as yeast, humans and plants.

«I argue that the boring billion was the anvil on which the eukaryote cell was forged.

Autophagy is the «self - eating» process of consuming unwanted elements in the cells of eukaryotes such as yeast, humans and plants.

Two billion years ago, an early cell swallowed an energy - producing microbe, giving birth to the mitochondria that are the hallmarks of all eukaryotes.

But its morphology and / or cell cycle might have complexities more often associated with eukaryotes.

Transfer RNAs (tRNAs) are ancient molecules and indispensable components of all living cells — they are found in all three kingdoms of life i.e., in archaea, bacteria and eukaryotes.

Although the majority of genes related to energy production, cell division, and metabolism in M. jannaschii are most similar to those found in Bacteria, most of the genes involved in transcription, translation, and replication in M. jannaschii are more similar to those found in Eukaryotes.

Such an autocatalytic system also provides an entirely novel mechanism for the growth of ring - shaped structures, which differs fundamentally from that used for daughter cell segregation in eukaryotic cell division: In eukaryotes, specific motor proteins which attach to the cell membrane and undergo active contraction are essential for this process, Denk points out.

On the other are the eukaryotes, whose complex cells have internal membranes, skeletons and transport systems.

Or consider the nuclear genes of the cells of advanced organisms (eukaryotes): At some early point in their evolution, these cells gained the help of the genes of a parasite or symbiont that became the mitochondrion, an organelle necessary for energy production.

The eukaryote tree abounds with single - celled organisms practicing the basics that combine to make multicellular reproduction possible.

His approach to the top of the tree (home to eukaryotes, which wrap their DNA in membrane - bound cell nuclei) would rule biology classrooms for decades.

Most scientists share the view that a symbiosis in which an archaeal host cell took up a bacterium ultimately gave rise to eukaryotes.