I cannot found the exercise anywhere, so I will just explain how the toxin works.
A toxin is a toxic substance made by a living organism such as a bacterium, a fungus, a plant or an animal.
Labil toxins are toxins which are by easily degraded. among these toxins, there is the toxin of Escherichia coli and the cholera toxin of <span>Vibrio cholerea.
</span>
The intracellular target of cholera toxin is adenylate cyclase, one of the most important eukaryotic cell regulatory systems. This enzyme is involved in the conversion of ATP into a cyclic AMP (cAMP), a crucial intracellular messenger in a wide variety of cellular processes.
Cholera toxin catalyzes the transfer of ADP-ribose from NAD (Nicotinamide Adenine Dinucleotide) to a specific arginine residue of the Gsa protein, resulting in the activation of adenylate cyclase and consequently the increase of the intracellular level cAMP. AMPc activates a cAMP-dependent protein kinase, which leads to phosphorylation of the protein, modification of ion transport and finally diarrhea.
Answer:
The correct answer is option A. "directional selection".
Explanation:
Directional selection is a type of natural selection at which traits with extreme characteristics are selected over traits with medium characteristics. In this case, a long-term climatic change resulted in all seeds that are the fountain of food for finch becoming hard. This will result in a directional selection on bill size in the finch population, where large-billed birds will be selected over small and medium-billed birds.
Answer:
It is secreted by the renal tubules
Explanation:
Answer: Sea stars move using a water vascular system. Water comes into the system via the madreporite. It is then circulated from the stone canal to the ring canal and into the radial canals.
Explanation: The radial canals carry water to the ampullae and provide suction to the tube feet.
