I would have to say probably d.
Answer:
the pathway will be under-expressed.
- the alpha subunit helps to bind with either GDP or GTP. when the α subunit is bound with GDP, it will be bound to β and γ subunits and thus forms an inactive state for G-protein.
- when the alpha subunit binds with the GTP, it becomes activated and dissociates β and γ subunits.
if G-protein Coupled Receptor is unable from dissociating β and γ subunits, then the pathway will go under expression.
The chemical qualities of the alpha subunit allow it to bind easily to one of two guanine subunits, GDP or GTP. The protein thus has two functional formations. When GDP is bound to the alpha subunit, the alpha subunit remains bound to the beta-gamma subunit to form an inactive trimeric protein.
G-proteins, cAMP, and Ion Channel Opening. The alpha subunit activates adenylate cyclase, in purple, and loses GTP. Adenylate cyclase converts ATP to cyclic AMP, which then activates Protein Kinase, shown in blue. Protein Kinase phosphorylates an ion channel, letting sodium ions rush into the cell.
As a result of the ligand binding to its site on the G-protein-linked receptor, A) the G-protein changes conformation and GTP replaces the GDP on the alpha subunit. ... Inactivation of the alpha subunit occurs when its own phosphorylase activity removes a phosphate from the GTP.
The correct options are as follows:
1. D.
<span>A clade refers to a group of organisms that are made up of evolutionary descendants that originated from a common ancestor. A clade that will survive a series of catastrophic events must be one that is made up of distantly related and diverse species. This is because, those species will have different type of adaptability capacity and will be able to adapt in different ways to the catastrophic events. Due to the differences in their ability to adapt, some of the specie will survive the catastrophic events even if others are wipe out.
2. B.
The mass extinction of one specie usually creates space for another new specie to survive. The new specie that survive the old one may possess the ability to adapt to the event that wipe out the former set of living organisms and thus, the new specie will be able to occupy and reproduce in their new space. Mass extinction is said to occur when the whole population of living organism living in an ecosystem are wipe out as a result of unfavorable conditions.
3. B.
Convergent evolution refers to the independent evolution of similar features in species that arise from different lineages. The species involved usually evolve these traits as a result of having to adapt to similar environments. Convergent evolution usually result in evolution of analogous structures, that is, structures that have similar forms or functions but which are not present in the last common ancestors of the species.
4. C.
In evolution, gradualism refers to theory that states that evolution occurs slowly and gradually, thus, large changes in evolution are actually product of small changes that occur over a long period of time. The theory of gradualism was originally proposed by James Hutton in 1795.
5. C.
Mass extinction refers to the wiping out of a a large number of species within a very short time. Mass extinction can occur as a result of severe unfavorable conditions that all the species in an ecosystem can not adapt to. An instance of this is a drastic decrease in global temperature after several massive volcanic eruptions.</span>
