Meiosis and unequal cytoplasmic division in seed plant ___ produce three small cells that disintegrate and one large megaspore. (a) pollen grains (b) microspores (c) gametophytes (d) ovules (e) pollen sacs. How many individual chromosomes would be ...
one of the specialized, columnar epithelial cells that produce mucus to trap debris. The cilia of the respiratory epithelium help remove the mucus and debris from the nasal cavity with a constant beating motion, sweeping materials
However, seed production was significantly lower in the small fragmented populations, possibly because of the low availability of pollinators and subsequent pollen limitation. In these fragmented populations, the mature flowering plants tended to be more dependent on vegetative reproduction for their ...
There is reproductive division of labour such that one or a few individuals, the queens and their mates, produce the colony offspring, while the majority of individuals, the workers, perform tasks such as foraging, nest construction and maintenance, and caring for offspring. The dependence of ...
Although these artificial materials resemble natural nacre, these techniques focused on mimicking the layered structure through anisotropic assembly of building blocks rather than employing a mineralization strategy that is adopted by natural living creatures to produce biomaterials. Very recently, a ...
Apart from very precise pollen placement in orchids, deceptive pollination also evolved, in which pollinators are cheated when they visit flowers that offer no reward. Deceptive pollination promotes cross-fertilization by reducing the visitation period of pollinators and discouraging returns to a single...
it gradually stabilized. These data showed that the three-jaw chuck shedding made the machine produce instantaneous large vibration. The vibration signal at the sensor surface is detected in the form of resistance change value. Therefore, it can be judged that the presently designed sensor is usefu...
However, reports suggested that some genes were possibly involved in pollen germination and pollen tube development (Supplementary Figure S11)81. GnTIV catalyzes the transfer of GlcNAc from UDP-GlcNAc in β1-4 linkage to α1,3-D-mannoside on GlcNAcβ1-2Manα1-6(GlcNAcβ...
(Supplementary Figure S11). In the phylogenetic tree, plant homologs were clustered together, none of which have been functionally characterized, to our knowledge. However, reports suggested that some genes were possibly involved in pollen germination and pollen tube development (Supplementary Figure S11...
that it could significantly affect tomato pollen viability, seed production, and plant morphology (Stotz et al.2009). ZmES1, a cysteine-rich defensin-like protein in maize, is able to interact with the potassium channel KZM1, leading to the rupture of maize pollen tubes to expel sperm (...