alternation of generations


  • WordNet 3.6
    • n alternation of generations the alternation of two or more different forms in the life cycle of a plant or animal
    • ***
Chambers's Twentieth Century Dictionary
    • Alternation of generations a complication in the life-history of plants, when the organism produces offspring unlike itself, but giving rise in turn to forms like the original parents
    • ***


Chambers's Twentieth Century Dictionary
L. generāre, -ātumgenus, a kind.


In literature:

The motor generator consisted of one alternating current motor driving two direct current generators.
"Tom Swift and his Electric Locomotive" by Victor Appleton
Such changes, however, reach their acme in the so-called alternate generations of some of the lower animals.
"On the Origin of Species" by Charles Darwin
Hydrozoa, alternation of generations in.
"More Letters of Charles Darwin Volume II" by Charles Darwin
This is termed alternation of generations.
"Scientific American Supplement, Vol. XXI., No. 531, March 6, 1886" by Various
The alternating tendencies so well marked in the generations of the Romanoff rulers made themselves felt at the accession of Nicholas II.
"The Development of the European Nations, 1870-1914 (5th ed.)" by John Holland Rose
August, 1883, an official of the Hungarian railway in Pesth was killed on touching a wire of a "Ganz" alternating-current generator.
"The American Architect and Building News, Vol. 27, No. 733, January 11, 1890" by Various
Such a telephone is at once the simplest known form of electric generator or motor for alternating currents.
"Cyclopedia of Telephony & Telegraphy Vol. 1" by Kempster Miller
There is then an alternation of generations, but there are not two sexual generations.
"Thomas Henry Huxley; A Sketch Of His Life And Work" by P. Chalmers Mitchell
In any case we have no parallel in these modifications to the alternate generations of the class system.
"Kinship Organisations and Group Marriage in Australia" by Northcote W. Thomas
In this case we have two kinds of generation combined, alternating with each other.
"Plain Facts for Old and Young" by John Harvey Kellogg
Heterogeny: the alternation of sexual and parthenogenetic generations.
"Explanation of Terms Used in Entomology" by John. B. Smith
Alternation of generations, 168.
"Our Common Insects" by Alpheus Spring Packard
What is meant by the expression "alternation of generations"?
"A Guide for the Study of Animals" by Worrallo Whitney
The systems of generation and distribution are generally 10,000 or 11,000 volts three-phase alternating current.
"Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2" by Various
The feeding-hoppers A are alternately charged every half-hour, so that the layer of fuel in the generator always remains 4 ft. deep.
"Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 4" by Various
There are, however, some flies which have viviparous larvae, and thus offer a typical case of alternation of generations.
"On the Origin and Metamorphoses of Insects" by Sir John Lubbock
By considering first the action of the simplest form of current generator, or elementary alternator.
"Hawkins Electrical Guide, Number One" by Nehemiah Hawkins
If thus constructed, the machine is a well-known form of alternating-current generator.
"The inventions, researches and writings of Nikola Tesla" by Thomas Commerford Martin
The history of the Liver-fluke is a most complicated example of alternation of generations.
"Stories of the Universe: Animal Life" by B. Lindsay
Alternation of generations, 96.
"Elementary Zoology, Second Edition" by Vernon L. Kellogg

In news:

Despite a vague veto threat by President Barack Obama, the House on Thursday easily passed a major defense policy bill that calls for continued development of a costly alternative engine for the Pentagon's next-generation fighter jet.
That's about the extent of the voter interest generated for the leading candidate so far by the alternate political reality that is Americans Elect.
The Army issued a draft request for proposals today to purchase over a 30-year period $7 billion worth of power generated from alternative energy sources, including solar, wind, geothermal and biomass.
With gas and oil prices at a premium, exploring alternative energy sources is possibly one of the greatest quests of our generation.
Its defeat is a setback for those hoping for reduced traffic congestion and more encouragement of alternative transportation to reduce generation of the greenhouse gases.
Thirty years ago, the Phoenix was the essential paper for a new generation of readers: those interested in a smart, countercultural alternative to the offerings of the mainstream press.
With a wink to the comic books of old, yet with a postmodern, Generation-X sensibility, local pop artists have found an outlet for their doodling ways in Alternating Crimes Publishing 's Hell Car Comix.
Generation & Measurement of High Alternating Voltages .

In science:

To illustrate this point we use an alternate method to generate n -detection test sets, based on a different definition of an n -detection test set.
Worst-Case and Average-Case Analysis of n-Detection Test Sets
Alternatively, one could take Γ to be the subgroup of Aut(Fl(E )) generated by the images of B and G via the homomorphisms corresponding to their respective actions.
Positivity in the cohomology of flag bundles (after Graham)
An alternative is to have the electroweak symmetry broken by a fourth generation of fermions and a new, strongly-interacting gauge interaction that acts on the third and fourth generations.
top2008 Conference Summary
By construction, the points are uniformly generated, hence exhibit homogeneity with respect to their supports for each class, but with respect to the unit square these alternative patterns are examples of departures from first-order homogeneity which implies segregation of the classes X and Y .
New Tests of Spatial Segregation Based on Nearest Neighbor Contingency Tables
An alternative approach emerging from discussions in the working group would be to consider the parton distribution functions to be an integral part of each Monte Carlo event generator, and to include them as parameters to be tuned.
Hadronic Final States and QCD: Summary
The linguistic situation actually is reflected in the literature generated in those regions; as an example, we display ( fig. 3) an extract of a bilingual novel from a Caribbean author, where segments in French and Creole alternate.
Soft Uncoupling of Markov Chains for Permeable Language Distinction: A New Algorithm
Alternatively, a large annihilation rate could be generated as the result of significant inhomogeneities in the spatial distribution of dark matter, such as the presence of a large, nearby dark matter subhalo .
Pulsars as the Sources of High Energy Cosmic Ray Positrons
Alternatively, if dark matter annihilations throughout the Milky Way’s halo are primarily responsible for the excess in the high energy cosmic ray positron spectrum, a small dipole anisotropy in the direction of the Galactic Center could also be generated.
Pulsars as the Sources of High Energy Cosmic Ray Positrons
Alternatively, in a model with fermions propagating in a five -dimensional AdS space, it is possible to break the electroweak symmetry via the condensation of the fourth generation, driven by their interactions with the Kaluza-Klein gauge bosons and by the presence of bulk higher-dimensional operators .
Four Statements about the Fourth Generation
One may wonder whether there exist alternative relativity groups with the same number of generators as special relativity.
Lorentz Violation: Motivation and new constraints
It has been shown, for instance, that the round functions of both DES and AES block ciphers are even permutations; furthermore it can be shown that these generate the alternating group A264 and A2128 , respectively.
Group theory in cryptography
Ralph Wernsdorf, The round functions of RIJNDAEL generate the alternating group, in Fast Software Encryption (J.
Group theory in cryptography
Alternatively just one cavity that supports a multimode field is an alternative to multiple-cavity generation of entangled coherent states [112–116].
Review of Entangled Coherent States
Figure 13 is a visualisation of the simulation, showing two alternate populations run for a thousand generations, with the one on the left from Figure 12 run under normal conditions, while the one on the right was run with a non-discriminating selection pressure.
Self-Organisation of Evolving Agent Populations in Digital Ecosystems
The MSSM with very heavy superpartners of the first two generation quarks, is a long-standing alternative to MFV.
Minimal Flavour Violation and Beyond