What that work did, he explained, was to trace the fundamental chemical structure of nucleic acids _ the material that passes genetic characteristics from the mother cell to the offspring.
42.
Spreading through a planktonic phase occurs by formation of special cells that have a hydrophilic surface and detach from the mother cells, or transient secretion of substances that mask the hydrophobic surface.
43.
The sporophyte produces spores ( hence the name ) by meiosis, a process also known as " reduction division " that reduces the number of chromosomes in each spore mother cell by half.
44.
A diploid cell ( megaspore mother cell ) in the ovule undergoes meiosis ( involving two successive cell divisions ) to produce four cells ( megaspores or female gametes ) with haploid nuclei.
45.
During sexual reproduction, which takes place by iso-gametes ( gametes of the same size ) even smaller than the zoospores, the iso-gametes escape through a hole in the cell wall of the mother cell.
46.
Within the megagametophyte one of the two sperm unites with the egg, forming a zygote, and the second sperm enters the central cell forming the endosperm mother cell, which completes the double fertilization process.
47.
Limited overexpression of the Sir2 gene results in a lifespan extension of about 30 %, if the lifespan is measured as the number of cell divisions the mother cell can undergo before cell death.
48.
Considerable confusion has resulted because diplospory is often defined to involve the megaspore mother cell only, but a number of plant families have a multicellular archesporium and the megagametophyte could originate from another archesporium cell.
49.
Once the coat is completed, the mother cell will lyse _ its membrane will disintegrate or burst open, the contents of the cell will spill out and the spore will be set free to find greener pastures.
50.
A persuasive feature of this explanation is that when the yeast cell divides, the cloying circles all remain with the mother cell; the daughter cell begins to age only when it accidentally creates a ribosomal DNA circle.
