The sporic life cycle results from an alternation between a haploid and a diploid organism. Because of this, sometimes this cycle is referred to as the “alternation of generations”. The diploid zygote first replicates by a series of mitotic divisions to form a multicellular diploid organism, known as a sporophyte.
Why do alternation of generations occur?
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 an alternation of generations life cycle?
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.
Why the life cycle of plants is referred to as having an alternation of generations?
Plants alternate between the diploid sporophyte and haploid gametophyte, and between asexual and sexual reproduction. Therefore, the life cycle of plants is known as alternation of generations. The ability of the plants to reproduce sexually and asexually helps them to adapt to different environments.
What type of meiosis does the plant life cycle and alternation of generations have?
All plants undergo a life cycle that takes them through both haploid and diploid generations. The multicellular diploid plant structure is called the sporophyte, which produces spores through meiotic (asexual) division.
What is alternation of generation in plants explain the Diplontic life cycle with suitable examples?
The gametophyte is the dominant phase. The diplontic life cycle is commonly seen in gymnosperms and angiosperms with some variations. However, an Alga called Fucus also shows this kind of life cycle. In a diplontic life cycle, the diploid sporophyte is dominant, photosynthetic and is the independent phase of the plant.
What is alternation of generation explain it with reference to the life cycle of obelia?
Alternation of generations is a type of life cycle that switches between two forms, the asexual polyp and the sexual medusa. Each reproduction, one form will give rise to the other. For example, a polyp will go through asexual reproduction to produce medusae and vice versa with sexual reproduction among medusae.
How is alternation of generations an effective way of ensuring that fit individuals survive?
-Alternation of generations is the form of sexual reproduction that algae can go through. It is through this process can the algae develop more genetic diversity which ultimately leads to one algae being “more fit” than the others which ensures the organisms survival when confronted with a threat.
Why is sporophyte generation dominant?
The gametophyte then makes gametes that fuse and grow into a sporophyte. In many plants, the sporophyte generation is the dominant generation. This means that the sporophyte is larger and lives longer than the gametophyte generation.
What is the alternation of generations in plants quizlet?
A life cycle in which there is both a multicellular diploid form, the sporophyte, and a multicellular haploid form, the gametophyte; characteristic of plants.
Why gametophyte is called so?
The gametophyte is the sexual phase in the life cycle of plants and algae. It develops sex organs that produce gametes, haploid sex cells that participate in fertilization to form a diploid zygote which has a double set of chromosomes.
Which of the following is a difference between the Anthophyta and Coniferophyta life cycles?
What are the major difference between plants in the phyla Coniferophyta & Anthophyta? … The major differences are that Coniferophyta refers to gymnosperms that produce makes seeds (e.g. furs, pines, & spruces), and Anthophyta refers to angiosperms that produce enclosed seeds (e.g. flowering plants and fruits).
What is alternation of generation Discuss with reference to Funaria plant?
Funaria plant and sporogonium represent gametophytic (n) and sporophytic (2n) generations, which follow each other in alternate sequence. This phenomenon is termed alternation of generations. In Funaria, main plant represents gametophytic generation and is haploid.
What type of life cycle do plants have?
All plants have a life cycle with alternation of generations. Plants alternate between diploid sporophyte and haploid gametophyte generations, and between sexual reproduction with gametes and asexual reproduction with spores.
Why are seed plants the most successful terrestrial plants?
The pollen grains are the male gametophytes, which contain the sperm (gametes) of the plant. … With such evolutionary advantages, seed plants have become the most successful and familiar group of plants, in part because of their size and striking appearance.
Why plants do not make their gametes by meiosis?
The haploid multicellular plants (or algae) are called gametophytes, because they make gametes using specialized cells. Meiosis is not directly involved in making the gametes in this case, because the organism is already a haploid. Fertilization between the haploid gametes forms a diploid zygote.