In angiosperms, the pollen grain is the male gametophyte and consists of two sperm cells within a larger vegetative cell, which produces a pollen tube1. The tip-growing pollen tube transports the cytoplasm and sperm cells to the apical region through the periodical production of thick callose plu...
How do freshwater fish sperm find the egg? The physicochemical factors guiding the gamete encounters of externally fertilizing freshwater fisheggflagellar dynamicsfreshwater fishguidanceovarian fluidspermatozoaThe lifespan of spermatozoa from externally fertilizing freshwater fish ranges from a few seconds to ...
. Furthermore, the combination of microfluidic chips and assisted reproductive technology (ART) is also a current research hotspot. The microfluidic technologies can be combined with various ART procedures to achieve embryo and gamete (sperm and oocyte) analysis, classification, operation, culture and ...
Male reproductive system is the organ system that producesmale gametes(sperms) that inherit paternal genes into their offspring. It consists of two basic structures called penis and scrotum, which locates around the pelvic girdle and mostly outside of the body in mammals. Scrotum covers the teste...
In this case, the population eventually consists of triploids only as long as selection against diploid apomicts is less than 1/3. However, if there is no selective disadvantage against either triploid, the population will have a higher frequency of the Aaa genotype than the AAa genotype (...
Human development begins at fertilization when a male gamete or sperm unites with a female gamete or oocyte to form a single cell-a zygote. This high… Gen-ethic Anxiety and Some Reflections on the Genome Project 01 January 2006 | Abdullah D. Dogan | Issue 53 (January - March 2006) Th...
(ii)In some species the inner layer of integument may become specialized to perform nutritive function for theembryosacand is called endothelium. Example:Asteraceae. 43. Name the cell which divides to form male nuclei. Answer:Generative cells of Microspore. ...
The presence of spermatozoa or oocytes in the oviduct altered the secretion of specific proteins. Most of these proteins are known to have an influence on gamete maturation, viability, and function, and there is evidence to suggest these proteins may prepare the oviductal environment for arrival ...
of male offspring, using semen quality as an indicator of potential heritability. In one analysis, sons of overweight mothers were found to have higher sperm DNA fragmentation compared with sons of normal weight mothers22. Some investigations have found associations of birthweight, a proxy for the...
Hybridogenesis consists of a gametogenetic process in which the hybrids exclude one of their parental genomes premeiotically, and transmit the other genome, clonally, to eggs and sperm. For example, in L-E complexes, P. esculentus hybrids have both the genomes of the parental species, L and...