What is Exosporic germination?
What is Exosporic germination?
In exosporic species, the smaller spores germinate into free-living male gametophytes and the larger spores germinate into free-living female gametophytes. In endosporic species, the gametophytes of both sexes are very highly reduced and contained within the spore wall.
What is Exosporic Gametophyte?
They have exosporic gametophytes — that is, the gametophyte is free-living and develops outside of the spore wall. Exosporic gametophytes can either be bisexual, capable of producing both sperm and eggs in the same thallus (monoicous), or specialized into separate male and female organisms (dioicous).
Do Monilophytes need water fertilization?
Water is required for fertilization of seedless vascular plants; most favor a moist environment. Modern-day seedless tracheophytes include lycophytes and monilophytes.
Which part of plant contains Sporogenous tissue?
anther
Sporogenous tissue is located at the centre of each microsporangium in a young anther. With the development of the anther, the sporogenous cells undergo meiotic division to form microspore tetrads. Each sporogenous cell is known as the pollen mother cell.
Is endospore germination reversible or irreversible?
Ø Endospore germination is an irreversible process. Ø If the spore sense unfavorable conditions after it germination, it cannot be returned to its quiescent stage, rather it perishes. Ø Germination of spores can be triggered by exposing the activated endospores to nutrients such as sugars or amino acids.
What is the optical density of endospore germination?
Upon germination, there is a marked decrease in the optical density between 500 and 600 nm. Analysis of optical density has been applied extensively to monitor the germination process. In chemical terms, endospore germination is a process that uses substrates (germinants and endospores) to accumulate a product (the vegetative cell) over time.
What are the three stages of endospore germination?
In this step involves three distinct steps such as; Activation: In this step, the endospore is getting prepared for the germination. This step is initiated when the endospore is heated. Germination: In this step involve the breaking of the spore’s dormant state.
What is a confounding factor in endospore germination?
A confounding factor is that populations of genetically identical endospores show heterogeneity in resistance and germination propensity [4,72,90]. This results in endospore sub-populations that have uncommonly high heat resistance or that germinate extremely slowly (‘superdormant’ endospores) [91].
