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In some cases, sporogenesis occurs via mitosis (e.g. in some fungi and algae). Mitotic sporogenesis is a form of asexual reproduction. Examples are the conidial fungi Aspergillus and Penicillium, for which mitospore formation appears to be the primary mode of reproduction.
This method of reproduction is found for example in conidial fungi and the red algae Polysiphonia, and involves sporogenesis without meiosis. Thus the chromosome number of the spore cell is the same as that of the parent producing the spores.
Usually, eggs are laid only by the queen, but the unmated workers may also lay haploid, male eggs either regularly (e.g. stingless bees) or under special circumstances. An example of non-viable parthenogenesis is common among domesticated honey bees. The queen bee is the only fertile female in the hive; if she dies without the possibility of a ...
For example, the ubiquitous and industrially important mold, Aspergillus niger, has no known sexual cycle. Thus Aspergillus niger was considered a form taxon. In contrast, isolates of its close relative, Aspergillus nidulans , revealed it to be the anamorphic stage of a teleomorph (the ascocarp or fruiting body of the sexual reproductive stage ...
Facultative parthenogenesis is extremely rare in nature, with only a few examples of animal taxa capable of facultative parthenogenesis. [33] One of the best-known examples of taxa exhibiting facultative parthenogenesis are mayflies; presumably, this is the default reproductive mode of all species in this insect order. [34]
Ochrophytes are capable of asexual reproduction by fragmentation, propagules, vegetative cell division, sporogenesis or zoosporogenesis. In addition, they are capable of sexual reproduction through gametes, by three different modes: isogamy, anisogamy or oogamy. [7]
The number of childfree women is at a record high: 48 percent of women between the ages of 18 and 44 don’t have kids, according to 2014 Census numbers. The Huffington Post and YouGov asked 124 women why they choose to be childfree.
Volvox carteri [1] is a species of colonial green algae in the order Volvocales. [2] The V. carteri life cycle includes a sexual phase and an asexual phase.V. carteri forms small spherical colonies, or coenobia, of 2000–6000 Chlamydomonas-type somatic cells and 12–16 large, potentially immortal reproductive cells called gonidia. [3]