# Chromatin undergoes condensation into compact patches against the nuclear envelope ( also known as the perinuclear envelope ) in a process known as pyknosis, a hallmark of apoptosis.

# The nuclear envelope becomes discontinuous and the DNA inside it is fragmented in a process referred to as karyorrhexis.

The main structures making up the nucleus are the nuclear envelope, a double membrane that encloses the entire organelle and unifies its contents from the cellular cytoplasm, and the nucleoskeleton ( which includes nuclear lamina ), a meshwork within the nucleus that adds mechanical support, much like the cytoskeleton, which supports the cell as a whole.

Because the nuclear membrane is impermeable to large molecules, nuclear pores are required to allow movement of molecules across the envelope.

The envelope is acquired by the capsid from an intracellular membrane in the virus ' host ; some examples would include the inner nuclear membrane, the golgi membrane, and the cell's outer membrane.

They share many similarities with the higher plants, including the presence of asymmetrical flagellated cells, the breakdown of the nuclear envelope at mitosis, and the presence of phytochromes, flavonoids, and the chemical precursors to the cuticle.

In eukaryotes the organelles of the endomembrane system include: the nuclear envelope, the endoplasmic reticulum, the Golgi apparatus, lysosomes, vacuoles, vesicles, peroxisomes, endosomes and the cell membrane.

The nuclear envelope is a membrane containing two layers, that encompasses the contents of the nucleus.

Diagram of the nucleus with the nuclear envelope shown as the orange portion.

The nuclear envelope surrounds the nucleus, separating its contents from the cytoplasm.

The outer membrane is also continuous with the inner nuclear membrane since the two layers are fused together at numerous tiny holes called nuclear pores that perforate the nuclear envelope.

The nuclear lamina is thought to help materials inside the nucleus reach the nuclear pores and in the disintegration of the nuclear envelope during mitosis and its reassembly at the end of the process.

The nuclear pores are highly efficient at selectively allowing the passage of materials to and from the nucleus, because the nuclear envelope has a considerable amount of traffic.

The microtubules invade the nuclear region after the nuclear envelope disintegrates, attaching to the chromosomes at the kinetochore.

For example, animals undergo an " open " mitosis, where the nuclear envelope breaks down before the chromosomes separate, while fungi such as Aspergillus nidulans and Saccharomyces cerevisiae ( yeast ) undergo a " closed " mitosis, where chromosomes divide within an intact cell nucleus.

Since such life utilised strong nuclear forces instead of electromagnetic interactions, it was posited that life might function millions of times faster than typical on Earth.

There are also situations where the isotopic distributions are not typical such as with heavy water used in some nuclear reactors which is artificially enriched with Deuterium.

Fission product yields by mass for thermal neutron fission of Uranium-235 | U-235, Pu-239, a combination of the two typical of current nuclear power reactors, and Uranium-233 | U-233 used in the thorium cycle.

While typical chemical reactions release energies on the order of a few eVs ( e. g. the binding energy of the electron to hydrogen is 13. 6 eV ), nuclear fission reactions typically release energies on the order of hundreds of millions of eVs.

Such steam explosions would be typical of the very diffuse assembly of materials in a nuclear reactor, even under the worst conditions.

The typical ligands for nuclear receptors are lipophilic hormones like the steroid hormones testosterone and progesterone and derivatives of vitamins A and D. To initiate signal transduction, the ligand must pass through the plasma membrane by passive diffusion.

The typical approach is to arrange the system so that ordinary single failures cause the mechanism to shut down in a safe way ( for nuclear power plants, this is termed a passively safe design, although more than ordinary failures are covered ).

It is termed weak because its typical field strength is several orders of magnitude less than that of both electromagnetism and the strong nuclear force.

The diagram at left shows a typical nuclear magnetic resonance ( NMR ) spectrum of a borane molecule.

A typical product from a nuclear reactor is thallium-201 and iridium-192.

A typical example is the technetium-99m generator used in nuclear medicine.

Such is most of typical total dosage ( with mean annual exposure from other sources amounting to 0. 4 mSv from cosmic rays, 0. 007 mSv from the legacy of past atmospheric nuclear testing along with the Chernobyl disaster, 0. 0002 mSv from the nuclear fuel cycle, and, averaged over the whole populace, 0. 6 mSv medical tests and 0. 005 mSv occupational exposure ).

Physicist Conrad Longmire has given numerical values for a typical case of the E1 pulse produced by a second generation nuclear weapon such as those used in high altitude tests of Operation Fishbowl in 1962.

He later carefully opens the package and finds a nuclear bomb, which he, in typical Clark-fashion, disarms and keeps.

An exciting evidence of nuclear activity within stars was the spectroscopic detection of radioactive technetium in the atmosphere of a red giant star in 1952, typical for the class of Tc-rich stars.

For typical applications in nuclear physics, where one particle's mass is much larger than the other the reduced mass can be approximated as the smaller mass of the system.

A typical aircraft carrier in the US military uses nuclear power to desalinate of water per day.

Genital warts, histopathologically, characteristically rise above the skin surface due to enlargement of the dermal papillae, have parakeratosis and the characteristic nuclear changes typical of HPV infections ( nuclear enlargement with perinuclear clearing ).

The typical eukaryotic nuclear intron has consensus sequences defining important regions.

In 2003, a study showed that about 69 % of kids in American living in a household that was a different structure than the typical nuclear family.

Different from the typical concept of anatomic radiology, nuclear medicine enables assessment of physiology.

The Orion nuclear pulse drive combines a very high exhaust velocity, from in typical interplanetary designs, with meganewtons of thrust.

The binding of nuclear receptors by glucocorticoids, heat, radiation, nutrient deprivation, viral infection, hypoxia and increased intracellular calcium concentration, for example, by damage to the membrane, can all trigger the release of intracellular apoptotic signals by a damaged cell.

Finally, a caspase 3 knock-out was characterized by ectopic cell masses in the brain and abnormal apoptotic features such as membrane blebbing or nuclear fragmentation.

Animal cloning, through somatic cell nuclear transfer ( SCNT ), allows for genetic replication of selected animals.

Social conservatives ( in the first meaning of the word ) in many countries generally favor the pro-life position in the abortion controversy and oppose human embryonic stem cell research ( particularly if publicly funded ); oppose both eugenics and human enhancement ( transhumanism ) while supporting bioconservatism ; support a traditional definition of marriage as being one man and one woman ; view the nuclear family model as society's foundational unit ; oppose expansion of civil marriage and child adoption rights to couples in same-sex relationships ; promote public morality and traditional family values ; oppose atheism, especially militant atheism, secularism and the separation of church and state ; support the prohibition of drugs, prostitution, and euthanasia ; and support the censorship of pornography and what they consider to be obscenity or indecency.

However, the use of advanced nuclear magnetic resonance methods to directly measure the mobility of water in living cells contradicts this idea, as it suggests that 85 % of cell water acts like that pure water, while the remainder is less mobile and probably bound to macromolecules.

Dolly ( 5 July 1996 – 14 February 2003 ) was a female domestic sheep, and the first mammal to be cloned from an adult somatic cell, using the process of nuclear transfer.

She was created using the technique of somatic cell nuclear transfer, where the cell nucleus from an adult cell is transferred into an unfertilised oocyte ( developing egg cell ) that has had its nucleus removed.

The combined hormone-receptor complex then moves across the nuclear membrane into the nucleus of the cell, where it binds to specific DNA sequences, effectively amplifying or suppressing the action of certain genes, and affecting protein synthesis.

When a nucleus is added to an egg during somatic cell nuclear transfer, the egg starts dividing in minutes, as compared to the days or months it takes for reprogramming during embryonic development.

Nuclear pores are large protein complexes that cross the nuclear envelope, which is the double membrane surrounding the eukaryotic cell nucleus.

There are about on average 2000 nuclear pore complexes ( NPCs ), in the nuclear envelope of a vertebrate cell, but it varies depending on cell type and the stage in the life cycle.

In contrast, eukaryotes make mRNA in the cell nucleus and then translocate it across the nuclear membrane into the cytoplasm, where protein synthesis then takes place.

As a result of the success of these experiments, Ian Wilmut, who helped create the first cloned animal Dolly the Sheep, has announced that he will abandon somatic cell nuclear transfer as an avenue of research.

In the same month, scientist Shoukhrat Mitalipov reports the first successful creation of a primate stem cell line through somatic cell nuclear transfer Martin Evans, a co-winner of the Nobel Prize in recognition of his gene targeting work.