A signal reaches a cell mostly in the form of a signalling molecule binding to a receptor on the cell surface. This binding activates a chain of events that amplifies the signal and transfers it inside the cell. Protein kinases phosphorylate proteins and cause their activation or deactivation, or in general modify their activity. When a signalling molecule binds to a receptor, a cascade is activated and the second messengers, such as cAMP, are synthesized. cAMP molecules activate the protein kinases, which phosphorylate specific proteins and activate them.
Answer:
Up
Explanation:
The force is the biggest (8N) so that's why it will move up
Creeping thistle continuously survives through easy germination of seeds. The Creeping thistle seed can be buried in undisturbed soil for over 20 years and still become growable. And also, the roots help in their growth. They absorb nutrients and regenerate to form new plants. Although the roots may be able to penetrate some meters down, most regeneration occurs within or just below the plow layer. Portions of the adjacent roots become thick due to the developing storage tissue which is where new shoots are formed.
Answer:
The microorganisms present metabolic wastes that serve as the primary source of food for other living things.
Bacteria that live free in the soil or in symbiosis with plants are essential to fix nitrogen, both nitrates and ammonia. These bacteria take nitrogen directly from the air, originating compounds that can be incorporated into the composition of the soil or living beings.
This property is restricted only to prokaryotes and is widely distributed among different groups of bacteria and some archaeobacteria. It is a process that consumes a lot of energy that occurs with the mediation of the enzyme nitrogenase, which the rest of the living organisms that cannot do or comply with this process is because they lack said enzyme.
Dunaliella is a genus of microscopic algae of the Chlorophyceae class and of the order Volvocales. All are unicellular, although with very varied morphologies.
Morphologically, its main characteristic is that they lack a rigid polysaccharide cell wall.
The ecology of this genus of green algae is characterized by its high tolerance to salinity, with eukaryotic organisms having greater tolerance to salt. They are euryhaline, adapted to salt concentrations from 50 mM NaCl to almost 5.5 M NaCl.
Explanation:
By nitrogen fixation is meant the combination of molecular nitrogen or dinitrogen with oxygen or hydrogen to give oxides or ammonia that can be incorporated into the biosphere. Molecular nitrogen, which is the majority component of the atmosphere, is inert and not directly usable by most living things. Nitrogen fixation can occur abiotic (without the intervention of living beings) or by the action of microorganisms (biological nitrogen fixation). Fixation in general involves the incorporation into the biosphere of a significant amount of nitrogen, which globally can reach about 250 million tons per year, of which 150 correspond to biological fixation.
