Can a mother cell further reproduce? (Yeast after bidding)
Mitosis is common to all eukaryotes; during this process, a parent cell splits into two genetically identical daughtercells, each of which contains the same number of chromosomes as theparent cell. Meiosis, on the other hand, only occurs in eukaryotic organisms that reproduce sexually.
1. Vegetative reproduction:
The vegetative reproduction takes place by means of ‘budding’. This method of reproduction takes place in favourable conditions when the yeast cells grow in sugar solution. From each yeast cell one or more small outgrowths are given out, which gradually enlarge in size, detached from the mother cells and act as independent individuals.The nucleus of the mother cells divides amitotically and transfers to the daughter cell. Several other outgrowths develop from the newly formed outgrowths, and sometimes the chains of the cells are seen. Very soon the yeast cells are detached from each other and act as new independent individuals.
2. Asexual reproduction:
This type of reproduction probably takes place in adverse conditions, especially when there is scarcity of nutrients and abundance of oxygen. The yeast cell enlarges in size and called the ‘ascus.’ The nuclues of the ascus divides twice producing four nuclei. Now around each nucleus the cytoplasm deposits and the four ascospores are formed. Sometimes eight ascospores may also be produced.
Each ascospore is surrounded by a thick wall. These spores are perennating bodies. They remain dormant in adverse conditions. On the approach of favourable conditions they germinate. The ascus wall bursts and the ascospores liberate « in the atmosphere. They are dispersed by wind from one place to another. On getting suitable media and appropriate weather conditions the ascospores germinate and the new individuals are formed by budding.
3. Sexual reproduction:
The sexual reproduction takes place very rarely in some of the species of yeasts. This takes place by conjugation. Two individuals come close to each other and the beak-like outgrowths are given out from them. These outgrowths fuse with each other. The nuclei of both individuals come in these beaks, the wall of contact dissolves and ultimately the nuclei fuse with each other giving rise to a zygote, which soon converts into an ascus. The diploid nucleus (2n) of asucs divides thrice producing eight nuclei. The first division is reductional to bring haploid (n) condition again.Around each nucleus the cytoplasm is deposited, they become walled and called the ascospores. On bursting the wall of ascus the ascospores are liberated. On getting suitable conditions they germinate and the new individuals are produced by budding.
1. Vegetative reproduction:
The vegetative reproduction takes place by means of ‘budding’. This method of reproduction takes place in favourable conditions when the yeast cells grow in sugar solution. From each yeast cell one or more small outgrowths are given out, which gradually enlarge in size, detached from the mother cells and act as independent individuals.The nucleus of the mother cells divides amitotically and transfers to the daughter cell. Several other outgrowths develop from the newly formed outgrowths, and sometimes the chains of the cells are seen. Very soon the yeast cells are detached from each other and act as new independent individuals.
2. Asexual reproduction:
This type of reproduction probably takes place in adverse conditions, especially when there is scarcity of nutrients and abundance of oxygen. The yeast cell enlarges in size and called the ‘ascus.’ The nuclues of the ascus divides twice producing four nuclei. Now around each nucleus the cytoplasm deposits and the four ascospores are formed. Sometimes eight ascospores may also be produced.
Each ascospore is surrounded by a thick wall. These spores are perennating bodies. They remain dormant in adverse conditions. On the approach of favourable conditions they germinate. The ascus wall bursts and the ascospores liberate « in the atmosphere. They are dispersed by wind from one place to another. On getting suitable media and appropriate weather conditions the ascospores germinate and the new individuals are formed by budding.
3. Sexual reproduction:
The sexual reproduction takes place very rarely in some of the species of yeasts. This takes place by conjugation. Two individuals come close to each other and the beak-like outgrowths are given out from them. These outgrowths fuse with each other. The nuclei of both individuals come in these beaks, the wall of contact dissolves and ultimately the nuclei fuse with each other giving rise to a zygote, which soon converts into an ascus. The diploid nucleus (2n) of asucs divides thrice producing eight nuclei. The first division is reductional to bring haploid (n) condition again.Around each nucleus the cytoplasm is deposited, they become walled and called the ascospores. On bursting the wall of ascus the ascospores are liberated. On getting suitable conditions they germinate and the new individuals are produced by budding.
