Answer:
Option D, A subject is observed both before and after two exposures to the treatment.
Explanation:
In A-B-A-B design the alphabets have following meaning
a) First A – It is the baseline value or the value measured before treatment
b) First B – It is the treatment measurement
c) Second A - It is the withdrawal of treatment
d) Second B – It is the reintroduction of treatment
The second A is known as the reversal phase in which the intervention is withdrawn to see if the target behavior returns to the baseline behaviour
Thus , there are two measurements involved one before the intervention and second after the intervention
Option D is correct
Answer;
-Structural isomers.
Explanation;
-Isomers are molecules that have the same molecular formula, but have a different arrangement of the atoms in space.
-Structural Isomers are molecules which have the same molecular formula but have different connectivities. That is; the molecules have the same molecular formula, but their atoms have different arrangements or bonds.
-For example, butane and isobutane are structural isomers, also called chain isomers. In chain isomers, the carbon atoms are connected in different orders. Isobutane and butane have a molecular formula of C4H10.
This capacity is known as Neuroplasticity. Neuroplasticity is the change in neural pathways and neurotransmitters that happens because of specific variables, similar to conduct, condition, or neural procedures. Amid such changes, the cerebrum participates in synaptic pruning, erasing the neural associations that are never again fundamental or helpful, and reinforcing the vital ones.
The proteins(particularly enzymes) of the membrane help chemical reactions.
An example would be enzymes involved in electron transport chain.
Producers. Without them there would be no food chain
