Apart from the central spermatogenous cell which eventually develops into spermatozoids
, an antheridium possesses a set of jacket cells that envelope this central spermatogenous zone (Leung and Naf, 1979).
where TA is the total number (in millions) of spermatozoids
in the whole ejaculate, A is the percentage of active spermatozoids
, and NK the percentage of normokinetic spermatozoids
applies to the spermatozoids
, but these are formed simultaneously
We already understand that gender is determined by a cascade of molecular signals that trigger differentiation of germinal cells into oocytes or spermatozoids
, one of which fertilizes a waiting egg
We could not detect any alteration in the form of the spermatids and spermatozoids
A quick sketch, circa 1949, shows a pile of lines more or less evocative of spermatozoids
to which two tires are added toward the bottom; "Will Jackson Pollock affect our cars?
Nevertheless, these techniques are widely used in many laboratories to study the chromosomes of human spermatozoids
, in fertilizing hamster eggs to determine the quality of semen from donors for artificial insemination.
were liberated by detachment of the operculum.
Fourth, since spermatozoids
require transport in water, male gamete dispersal distance of ferns tends to be very limited (within a few centimeters; Peck et al.
can be observed in the lumen of empty follicles that also have abundant hemocytes.
It is important that the gametophytes are always covered with a film of warm water in order to prevent retardation of development and for fertilization success (the spermatozoids
must be able to swim to the egg cells).