What is alternation of generation simple definition?
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?
It describes an alternation in forms which occur in plants and some Protists. One form is the diploid sporophyte with 2n chromosomes. 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.
Why is it called alternation of generations?
The multicellular haploid plant structure is called the gametophyte, which is formed from the spore and give rise to the haploid gametes. The fluctuation between these diploid and haploid stages that occurs in plants is called the alternation of generations.
What is meant by alternation of generations quizlet?
Alternation of Generations. This term refers to the life cycle of most plants in which the generations alternate between haploid gametophytes and diploid sporophytes. All embryophytes and some algae undergo this process.
What is alternation of generation Class 11 explain?
Hint: Alternation of generation refers to the occurrence of diploid and haploid multicellular organisms, giving rise to new organisms. This process allows for both the dynamic and volatile action of sexual reproduction as well as consistence act of asexual reproduction. It is most commonly found in plants and algae.
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 is alternation of generations in cnidarians?
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.
How does alternation of generations happen?
Alternation of generations (also known as metagenesis or heterogenesis) is the type of life cycle that occurs in those plants and algae in the Archaeplastida and the Heterokontophyta that have distinct haploid sexual and diploid asexual stages. The haploid spores germinate and grow into a haploid gametophyte.
What happens in alternation of generations?
Alternation of generations is defined as the alternation of multicellular diploid and haploid forms in the organism’s life cycle, regardless of whether these forms are free-living. The sporophyte produces free-swimming haploid spores by meiosis that germinate into haploid gametophytes.
What is alternation of generation for Class 9?
“Alternation of generations is a type of life cycle in which subsequent generations of plants alternate between diploid and haploid organisms.”
What is alternation of generation explain with diagram?
Alternation of generations is a term primarily used to describe the life cycle of plants. 2. A multicellular gametophyte, which is haploid with n chromosomes, alternates with a multicellular sporophyte, which is diploid with 2n chromosomes, made up of n pairs.
What is the meaning of alternation of generations?
Alternation of Generations Definition. “Alternation of generations is a type of life cycle in which subsequent generations of plants alternate between diploid and haploid organisms.”.
How is alternation of generations similar to sexual reproduction?
Alternation of generations is common in plants, algae, and fungi. This can be compared to the sexual reproduction in animals where both haploid and diploid cells are found in every generation. Plants alternate between the diploid sporophyte and haploid gametophyte, and between asexual and sexual reproduction.
What kind of moss is an alternation of generations?
Typical moss: green haploid body and brown diploid sporophyte. The term alternation of generations is used to describe a process in the life cycle of some eukaryotes. It describes an alternation in forms which occurs in plants and some protists. One form is diploid, with 2n chromosomes: the sporophyte.
What makes plants adaptable to the alternation of generations?
Fossil evidence, and the existence of many algae with simplified alternation of generation life cycles, hints that the evolutionary advantage of sexual reproduction through the alternation of generations is what made terrestrial plants adaptable enough to colonize the land.