What is isomorphic and Heteromorphic?
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.
What is Heteromorphic type of alternation of generation?
Land plants all have heteromorphic (anisomorphic) alternation of generations, in which the sporophyte and gametophyte are distinctly different. The sporophyte grows up from the archegonium. Its body comprises a long stalk topped by a capsule within which spore-producing cells undergo meiosis to form haploid spores.
What is Haplontic alternation of generation?
For plants and many algae, there are two multicellular stages, and the life cycle is referred to as alternation of generations. haplontic life cycle — the haploid stage is multicellular and the diploid stage is a single cell, meiosis is “zygotic”.
What is homologous alternation of generation?
Supporters of homologous alternation now promoted a model in which land plants had been derived from an algal ancestor with an isomorphic alternation of haploid and diploid generations whereas supporters of antithetic alternation favored a model in which land plants were derived from a haploid algal ancestor with …
What do you mean by 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 …
What is the importance of alternation of generation?
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 is alternation of generation explain?
Alternation of generations, also called metagenesis or heterogenesis, in biology, the alternation of a sexual phase and an asexual phase in the life cycle of an organism. The two phases, or generations, are often morphologically, and sometimes chromosomally, distinct.
What is alternation of generation with example?
In algae, fungi, and plants, alternation of generations is common. Among animals, many invertebrates have an alternation of sexual and asexual generations (e.g., protozoans, jellyfish, flatworms), but the alternation of haploid and diploid generations is unknown.
Which of the following is true for alternation of generation?
So, the correct answer is ‘Diploid generation is followed by haploid generation’.
What best describes the alternation of generations?
Answer: The correct answer is 3) A gametophyte is a haploid phase. Alternation of generation is a type of sexual life cycle that is found in all plants and some algae. In these organisms, a multicellular gametophyte that is haploid phase alternates with a multicellular sporophyte, which is a diploid phase.
Why is alternation of generations important?
What is alternation of generation give example?
What does heteromorphic alternation of generation mean?
Heteromorphic alternation of generations means that there is a sporophyte version of the plant and a gametophyte version of the plant that each participate in that plant species’s life cycle. The gametophyte plant (or plants) make the gametes.
Which is the dominant phase in the alternation of generations?
Alternation of generations. In terms of chromosomes, the gametophyte is haploid (has a single set of chromosomes), and the sporophyte is diploid (has a double set). In bryophytes, such as mosses and liverworts, the gametophyte is the dominant life phase, whereas in angiosperms and gymnosperms the sporophyte is dominant.
What are the two categories of alternation in biology?
Biologists recognize two categories of alternation: the first if the sporophyte and the gametophye forms are more or less identical, alternation is called isomorphic; and second if the forms have very different appearances, alternation is called heteromorphic.
Which is more advantageous a heteromorphic or isomorphic life cycle?
Under what circumstances will a heteromorphic life cycle be more advantageous than an isomorphic life cycle. Mathematical model: We develop mathematical models for an optimal life cycle in one environment where productivity changes seasonally. The beginning and the end of generations are chosen to maximize the population growth rate.
Heteromorphic alternation of generations means that there is a sporophyte version of the plant and a gametophyte version of the plant that each participate in that plant species’s life cycle. The gametophyte plant (or plants) make the gametes.
Where does isomorphic alternation of generations occur in algae?
It is notable that isomorphic alternation of generations occurs only in certain algae and aquatic molds, while heteromorphic alternation of generations is the rule in land plants.
Under what circumstances will a heteromorphic life cycle be more advantageous than an isomorphic life cycle. Mathematical model: We develop mathematical models for an optimal life cycle in one environment where productivity changes seasonally. The beginning and the end of generations are chosen to maximize the population growth rate.
Which is an example of an alternation of generations?
Alternation of generations occurs in almost all marine algae. In most red algae, many green algae, and a few brown algae, the phases are isomorphic and free-living. Some species of red algae have a complex triphasic alternation of generations. Kelp are an example of a brown alga with a heteromorphic alternation of generations.