It is true.
Hermie seed's only produce females because they are a product of asexul reproduction. (See below)
The reason this is neat is because cannabis is a diclinous plant (meaning it doesn't normally grow male and female flowers year round - like a day lily for example). It's also an angiospern (flower bearing) plant, and of those I (think) less than 10% are or can be diclinous like cannabis. Most plant species do produce pollen and a stamen all in one, however many species have seperate male and female specimen. Not all plant species have male and female but undergo sexuality changes, like I said, less than 10% - I bet there is a better number, or even maybe a list. It's interesting stuff to enlighten yourself to.
As for the MOB being female question. You may be able to figure it out after reading this. If not we will still help!
Anyways. If you read the below from wikipedia regard asexual reproduction I'm sure you will understand your question.
Asexual reproductionMain article: Asexual reproduction
Asexual reproduction is the process by which an organism creates a genetically similar or identical copy of itself without a contribution of genetic material from another individual. Bacteria divide asexually via binary fission; viruses take control of host cells to produce more viruses; Hydras (invertebrates of the order
Hydroidea) and yeasts are able to reproduce by budding. These organisms often do not possess different sexes, and they are capable of "splitting" themselves into two or more individuals. On the other hand, some of these species that are capable of reproducing asexually, like hydra, yeast (See Mating of yeasts] and jellyfish, may also reproduce sexually. For instance, most plants are capable of vegetative reproductionreproduction without seeds or sporesbut can also reproduce sexually. Likewise, bacteria may exchange genetic information by conjugation. Other ways of asexual reproduction include parthenogenesis, fragmentation and spore formation that involves only mitosis. Parthenogenesis (from the Greek παρθένος parthenos, "virgin", + γένεσις genesis, "creation") is the growth and development of embryo or seed without fertilization by a male. Parthenogenesis occurs naturally in some species, including lower plants (where it is called apomixis), invertebrates (e.g. water fleas, aphids, some bees and parasitic wasps), and vertebrates (e.g. some reptiles,[SUP]
[1][/SUP] fish, and, very rarely, birds[SUP]
[2][/SUP] and sharks[SUP]
[3][/SUP]). It is sometimes also used to describe reproduction modes in hermaphroditic species which can self-fertilize.