Spore wall ultrastructure and development in a basal euphyllophyte: Psilophyton dawsonii from the Lower Devonian of

Sol Noetinger1, Sandra L Strayer2, Alexandru M F Tomescu2

  • 1Museo Argentino de Ciencias Naturales, Av. Angel Gallardo 470, C1405DJR, Ciudad A. de Buenos Aires, Argentina.

Abstract

Related Concept Videos

Plant Cell Wall02:43

Plant Cell Wall

The plant cell wall gives plant cells shape, support, and protection. As a cell matures, its cell wall specializes according to the cell type. For example, the parenchyma cells of leaves possess only a thin, primary cell wall.
60.5K
Plant Cell Wall01:07

Plant Cell Wall

Plant cells have a cell wall, a rigid outer covering that protects the cell and provides shape and support. During cell division, a mixture of enzymes, proteins, and glucose molecules is transported via vesicles to the center of the cell. These vesicles continuously fuse and build a cell plate between the dividing cells. As the cell plate matures, new polysaccharides are added to it to form the cell walls of the daughter cells. The predominant polysaccharide in the cell wall is cellulose, made...
7.7K
Laminins are the Adhesive Proteins of Basal Lamina00:55

Laminins are the Adhesive Proteins of Basal Lamina

Laminins are heterotrimeric proteins with high molecular mass found in the extracellular matrix. Each laminin molecule is composed of three chains, viz. alpha, beta, and gamma, coded by five, four, and three paralogous genes, respectively. Laminins are categories based on the compositions of the three chains.
In humans, the five forms of alpha chains are LAMA 1, LAMA 2, LAMA 3, LAMA 4, and LAMA 5. The four forms of beta chains are LAMB 1, LAMB 2, LAMB 3, and LAMB 4. The three forms of gamma...
3.3K
Basal Lamina are the Specialized Form of ECM01:03

Basal Lamina are the Specialized Form of ECM

The basal lamina is a thin extracellular layer that lies underneath the cells and separates them from other tissues. The three layers of the basal lamina are lamina lucida, lamina densa and lamina reticularis. The basal lamina, a mixture of glycoproteins and collagen, provides an attachment site for the epithelium, separating it from underlying connective tissue. The framework of basal lamina has other essential proteins such as laminins mesh, perlecan, entactin, and type IV collagen.
Proteins...
3.8K
Type IV Collagen of Basal Lamina01:05

Type IV Collagen of Basal Lamina

Type IV collagen is a 400 nm long, network-forming collagen that acts as a barrier between the epithelial and endothelial cells. Type IV collagen  forms the backbone of the basement membrane by scaffolding with laminin, entactin, proteoglycans, and fibronectin. Apart from rendering structural support to the basement membrane, it also helps entail signaling potentials necessary for both pathological and physiological functions.
A type IV collagen molecule has six alpha chains which can...
3.1K
Composite Masonry Walls01:18

Composite Masonry Walls

Composite masonry walls combine multiple wythes of the same or different masonry materials to create a unified structure. These walls feature wythes that are bonded together either through mortar-filled collar joints, grouted spaces, or more commonly, with rigid metal ties and reinforcements, with the use of masonry header units being rare. Metal ties are preferred because they effectively minimize water penetration, as these walls primarily absorb moisture and then release it into the...
1.7K