Search results
Results from the WOW.Com Content Network
The outer layer of cells of an apical meristem. This is known as the tunica. In biology, a tunica (/ ˈ t (j) uː n ɪ k ə /, [1] UK: / ˈ tʃ uː n ɪ k ə /; pl.: tunicae) is a layer, coat, sheath, or similar covering. The word came to English from the Neo-Latin of science and medicine.
Plant embryonic development, also plant embryogenesis, is a process that occurs after the fertilization of an ovule to produce a fully developed plant embryo. This is a pertinent stage in the plant life cycle that is followed by dormancy and germination . [ 1 ]
Cells at the shoot apical meristem summit serve as stem cells to the surrounding peripheral region, where they proliferate rapidly and are incorporated into differentiating leaf or flower primordia. The shoot apical meristem is the site of most of the embryogenesis in flowering plants.
The tunica albuginea is composed of short connective tissue fibers. It is located immediately inside the surface epithelium (previously known as germinal epithelium) which is continuous with the peritoneum. It is non-vascularised. [1] It is thinner than the tunica albuginea of the testis, and its thickness varies across the ovary. [1]
The primitive jawless fish have only a single testis, located in the midline of the body, although even this forms from the fusion of paired structures in the embryo. [2] Under a tough membranous shell, the tunica albuginea, the testis of some teleost fish, contains very fine coiled tubes called seminiferous tubules.
Stromal cells associated with maturing follicles may acquire endocrine function and secrete estrogens. The entire ovarian stroma is highly vascular. [1] On the surface of the organ this tissue is much condensed, and forms a layer (tunica albuginea) composed of short connective-tissue fibers, with fusiform cells between them.
Close-up of a Schlumbergera flower, showing part of the gynoecium (specifically the stigma and part of the style) and the stamens that surround it. Plant reproductive morphology is the study of the physical form and structure (the morphology) of those parts of plants directly or indirectly concerned with sexual reproduction.
Plant morphology treats both the vegetative structures of plants, as well as the reproductive structures. The vegetative (somatic) structures of vascular plants include two major organ systems: (1) a shoot system, composed of stems and leaves, and (2) a root system. These two systems are common to nearly all vascular plants, and provide a ...