Answer: mucilaginous sheath
Explanation:
These algae are known as "blue algae" because of their pigmentation or "cyanobacteria" because they are prokaryotes. Microbiologists classify cyanobacteria in the realm of Eubacteria. They are the only prokaryote algae. The cellular organization is prokaryotic, without nuclei or organelles. Respiration takes place at the level of plasmalemma and thylakoids. In the center (nucleoplasm), cells contain their genome and circular plasmids. Cyanobacteria often also have a mucilaginous sheath common to many trichomes.
These organisms contain several carotenoid pigments, particularly myxoxanthophyll, which does not occur in any other algae group. Some cyanobacteria are strictly phototrophic, others are optional: they are phototrophic when in the presence of light, but may grow in obscurity using an organic carbon source. Others can use a source of organic carbon as well as inorganic carbon, but only in the presence of light.
Answer:
Troponin and calcium ions.
Explanation:
Troponin is a component of thin filament along with tropomyosin and actin. It is a protein complex to which calcium binds and start the production of muscular force.
Calcium also playing a very important role in muscle contractions, it binds with troponin and helping to move tropomyosin.
When calcium ion attached to troponin, then conformational changes occurs in troponin shape and moves which allow tropomyosin going away from its inhibitory position from the myosin-binding sites on actin. After this, the energized myosin head starts binding to the actin molecules and starts the cross bridge cycle, which helping in shortening the muscle's fiber.
Los seres invertebrados y los vertebrados tienen más elementos en común de lo que se pensaba. Un estudio, con participación del Consejo Superior de Investigaciones Científicas (CSIC), prueba que existe gran similitud entre los sistemas excretores de ambos grupos de animales. Según la investigación, las células encargadas de filtrar la sangre en la formación de orina, alojadas en los riñones de vertebrados, son similares a las que realizan una función análoga en invertebrados.
a cell is the smallest structural and functional unit of an organism
