Answer:
Constitutive activation is the alteration of a protein or signaling pathway such that it is functional or engaged even in the absence of an upstream activating event. For example, RasD is constitutively active because it cannot bind GAP and therefore remains in the GTP-bound, active state even when cells are not stimulated by growth factor to activate a receptor tyrosine kinase.
Constitutively active Ras is cancer promoting because cells will proliferate in the absence of growth factors, and thus normal regulatory mechanisms for cell proliferation are bypassed.
(a) A mutation that resulted in Smad3 binding Smad4, entering the nucleus, and activating transcription independent of phosphorylation by the TGFβ receptor would render Smad3 constitutively active.
(b) A mutation that made MAPK active as a kinase and able to enter the nucleus without being phosphorylated by MEK would render MAPK constitutively active.
(c) A mutation that prevented NF-KB from binding to IK-B or that allowed NF-KB to enter the nucleus and regulate transcription even when bound to IK-B would render NF-KB constitutively active.
Answer:
No change occurs in phenotype.
Explanation:
This can happen in many situations:
perhaps the mutation occurs in a stretch of DNA with no function, or perhaps the mutation occurs in a protein-coding region, but ends up not affecting the amino acid sequence of the protein.
Answer:
The primary means for transmitting messages between the brain and the rest of the body is the <u>spinal cord</u>.
Explanation:
The spinal cord is the main pathway of the nervous system. The impulses are transmitted to the brain through bundles of ascending nerve fibers, while the descending fibers transmit impulses in the opposite direction. Signals are transported to and from different parts of the body along the fibers of the pair of spinal nerves, which form intersections with the spinal cord through their dorsal and ventral roots; the sensory and motor fibers converge in the gray matter of the medulla.
Explanation:
Water provides a safety net for mosquitoes to move into developmental periods and grow. In the egg stage, the female lays roughly 300 eggs that float atop the water's surface. This is why it is so important to eliminate any standing water around your property.
Answer:
Predator-prey relation.
Explanation:
A predator is defined as an organism that hunts another individual, whereas a prey refers to the organism that is eaten by the predator. They tend to co-evolve (evolve together). <u>The prey is essential for the predator to survive, while the predator controls the prey populations by hunting some of the individuals.</u>
Predator-prey relations are interactions that occur between two species where one species (prey) represents a food source for the other species (predator).
The turtle (prey) is essential for the survival of the jaguar (<em>Panthera onca)</em>, while the jaguar controls the populations of turtles by preying upon them. Therefore, this is a predator-prey relation.
