The mammalian embryo cannot develop without the placenta. Its specialized cells
(trophoblast, endoderm, and extraembryonic mesoderm) form early in development. They …

In many ways, plants offer unique systems through which to study sex determination.
Because the production of unisexual flowers has evolved independently in many plant …

This review will summarize molecular and genetic analyses aimed at identifying the
mechanisms underlying the sequence of events during plant zygotic embryogenesis. These …

The extremely reduced, three-celled, haploid male plant (male gametophyte) of flowering
plants has a number of specialized functions to perform. The primary functions are the …

The majority of the world's flowering plants are hermaphrodite but many of them encourage
cross pollination by means of spatial or temporal separation of eggs and pollen, or by …

The plant life cycle is characterized by the alternation of generations between a diploid
sporophyte and a haploid gametophyte. The sporophyte functions to produce spores, which …

The author offers an overview of pollen biology and biotechnology for students and
researchers in areas such as reproductive biology, biotechnology, aeropalynology, plant …

Many flowering plants reproduce sexually and generate variation by the process of
recombination. Because the possibility of continued evolution is dependent, at least in part …

S proteins, pistil-specific ribonucleases that cosegregate with S alleles, have previously
been shown to control rejection of self-pollen in Petunia inflata and Nicotiana alata, two …

In plant sexual reproduction, pollen tubes elongate from the stigma, through the stylar
transmitting tissue, to the ovary of the pistil to deliver the male gametes for fertilization. TTS …