Answer:
The order must be K2→K1, since the permanently active K1 allele (K1a) is able to propagate the signal onward even when its upstream activator K2 is inactive (K2i). The reverse order would have resulted in a failure to signal (K1a→K2i), since the permanently active K1a kinase would be attempting to activate a dead K2i kinase.
Explanation:
- You characterize a double mutant cell that contains K2 with type I mutation and K1 with type II
mutation.
- You observe that the response is seen even when no extracellular signal is provided.
- In the normal pathway, i f K1 activat es K2, we expect t his combinat ion of two m utants to show no response with or without ext racell ular signal. This is because no matt er how active K1 i s, it would be unable to act ivate a mutant K2 that i s an activit y defi cient. If we reverse the order, K2 activating K1, the above observati on is valid. Therefore, in the normal signaling pathway, K2 activates K1.
Answer:
Genetic Mutation
Explanation:
Speciation can be driven by evolution, which is a process that results in the accumulation of many small genetic changes called mutations in a population over a long period of time.
There are a number of different mechanisms that may drive speciation.
Two of them to point out here.
1. natural selection
2. genetic drift
genetic drift describes random fluctuations in allele frequencies in populations, which can eventually cause a population of organisms to be genetically distinct from its original population and result in the formation of a new species.
A. True ! Energy can be lost, but not created nor destroyed.
False, it happens through the light independent reaction.
