1a : the act or process of alternating or causing to alternate. b : alternating occurrence : succession. 2 : inclusive disjunction. 3 : the occurrence of different allomorphs or allophones.
What is an example of alternation?
An example of a phonologically conditioned alternation is the English plural marker commonly spelled s or es. If the preceding sound is a sibilant consonant (one of /s/, /z/, /ʃ/, /ʒ/), or an affricate (one of /tʃ/, /dʒ/), the plural marker takes the form /ᵻz/.
Is there a word alternation?
the act or process of alternating or the state of being alternated. alternate succession; repeated rotation: the alternation of the seasons.
How do you use alternation in a sentence?
successive change from one thing or state to another and back again. (1) The alternation of sun and snow continued for the rest of our holiday. (2) One guess is that they work in strict alternation, perhaps in obedience to a monthly nerve signal from the brain.
What is the difference between alternation and alteration?
is that alternation is the reciprocal succession of (normally two) things in time or place; the act of following and being followed by turns; alternate succession, performance, or occurrence; as, the alternation of day and night, cold and heat, summer and winter, hope and fear while alteration is the act of altering or
Do algae have alternation of generations?
Alternation of generations occurs in almost all multicellular red and green algae, both freshwater forms (such as Cladophora) and seaweeds (such as Ulva). In most, the generations are homomorphic (isomorphic) and free-living.
Do all plants have alternation of generations?
All plants alternate generations. There is an evolutionary trend from sporophytes that are nutritionally dependent on autotrophic (self-feeding) gametophytes to the opposite‐gametophytes that are dependent on autotrophic sporophytes.
What is isomorphic alternation of generation?
In an isomorphic alternation of generations (found in some algae, for example) the sporophyte and gametophyte are morphologically similar or identical; in a heteromorphic alternation of generations they are dissimilar (e.g. in mosses the gametophyte is the dominant and conspicuous generation, whereas in higher plants
Why is alternation of generations important?
The alternation of generations allows for both the dynamic and volatile act of sexual reproduction and the steady and consistent act of asexual reproduction. When the sporophyte creates spores, the cells undergo meiosis, which allows the gametophyte generation to recombine the genetics present.
What kind of part of speech is alternation?
The reciprocal succession of (normally two) things in time or place; the act of following and being followed by turns; alternate succession, performance, or occurrence; as, the alternation of day and night, cold and heat, summer and winter, hope and fear.
What is alternation in electrical engineering?
One-half cycle of an alternating quantity is called an alternation. An alternation spans 180° electrical. Thus in Fig. ( a), the positive or negative half of alternating voltage is the alternation.
What’s an example of alliteration?
As a method of linking words for effect, alliteration is also called head rhyme or initial rhyme. For example, “humble house”, “potential power play”, “picture perfect”, “money matters”, “rocky road”, or “quick question”. A familiar example is “Peter Piper picked a peck of pickled peppers”.
What is the precise meaning of spores?
(Entry 1 of 3) : a primitive usually unicellular often environmentally resistant dormant or reproductive body produced by plants, fungi, and some microorganisms and capable of development into a new individual either directly or after fusion with another spore.
What does giving an ultimatum mean?
: a final proposition, condition, or demand especially : one whose rejection will end negotiations and cause a resort to force or other direct action.
What is alternation of generations give examples?
The classic example is the mosses, where the green plant is a haploid gametophyte and the reproductive phase is the brown diploid sporophyte. The two forms occur together. In bryophytes and mosses, the gametophyte is the dominant generation and the sporophyte are sporangium bearing stalks growing from the gametophyte.
What is triphasic alternation of generation?
The triphasic life cycle includes an alternation of two diploid or sporophyte generations. There are two diploid phases and one haploid phase. No motile stage occurs during the entire life of red algae. The spores and gametes are transported by the water in a passive manner.
Do Chlorophytes have alternation of generations?
Despite the filmy appearance, Ulva is quite tough and survives well in zones of pounding waves. They exhibit an isomorphic alternation of generation (i.e. the haploid thalli look like the diploid thalli).
What is alternation of generation explain giving example of life cycle of a plant?
In algae, fungi, and plants, alternation of generations is common. The sexual phase, called the gametophyte generation, produces gametes, or sex cells, and the asexual phase, or sporophyte generation, produces spores asexually.
Do fungi have alternation of generations?
Alternation of generations is a reproductive cycle of certain vascular plants, fungi, and protists. This cycle, from gametophyte to gametophyte, is the way in which plants and many algae undergo sexual reproduction.
How do you know if a plant is gametophyte or sporophyte?
Gametophytes are haploid (n) and have a single set of chromosomes, whereas Sporophytes are diploid (2n), i.e., they have two sets of chromosomes.
What’s the difference between Heteromorphic and isomorphic?
Species with heteromorphic life cycle have a large multicellular body in one generation but have a microscopic body in the other generation of a year. In contrast, isomorphic species have both diploid and haploid life forms with very similar morphology, having more than two generations in a year.
Does Plasmodium have alternation of generations?
Plasmodium is considered from the sporozoan parasites that parasites on both the human and female Anopheles mosquito, In the life cycle of Plasmodium, there is a generation that reproduces sexually by gametes (in mosquito) and alternates with generations that reproduce asexually by sporogony (in mosquito) and by
What is isomorphic alternation of generation explain it by the life cycle of Ectocarpus?
This typical life cycle of Ectocarpus exhibits morpholigically identical filaments representing sporophyte and gametophyte—isomorphic alternation of generations. While the one formed by the direct germination of the zygote bearing unilocular sporangia and plurilocular sporangia is the sporophyte having diploid cells.
What is the adaptive significance of alternation of generations in the major groups of plants?
Plants alternate between diploid sporophyte and haploid gametophyte generations, and between sexual and asexual reproduction. The ability to reproduce both sexually and asexually gives plants the flexibility to adapt to changing environments. Their complex life cycle allows for great variation.
Do gymnosperms have alternation of generations?
The life cycle of a gymnosperm involves alternation of generations, with a dominant sporophyte in which reduced male and female gametophytes reside. All gymnosperms are heterosporous. The male and female reproductive organs can form in cones or strobili.
What is the meaning of alternative ending?
An alternate ending (or alternative ending) is an ending of a story that was considered, or even written or produced, but ultimately discarded in favour of another resolution. Generally, alternative endings are considered to have no bearing on the canonical narrative.
What does fluctuating mean?
1 : to shift back and forth uncertainly Oil prices fluctuated. Temperatures fluctuated. 2 : to rise and fall in or as if in waves The boat fluctuated on the rough sea. transitive verb. : to cause to fluctuate.
What is the meaning of alternate reality?
Alternate reality is often a synonym for parallel universes in fiction. Alternate reality may also refer to: Alternate history, a genre of fiction consisting of stories that are set in worlds in which historical events unfold differently from the real world.
What does it mean every other day?
If something happens every other day or every second day, for example, it happens one day, then does not happen the next day, then happens the day after that, and so on. You can also say that something happens every third week, every fourth year, and so on.