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The second A is known as the reversal phase in which the intervention is withdrawn to see if the target behavior returns to the baseline behaviour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:
Stem cells are special human cells that have the ability to develop into many different cell types, from muscle cells to brain cells. In some cases, they also have the ability to repair damaged tissues.
Explanation:
Answer:Blood
Explanation:Bones contain bone marrow. Red and white blood cells are produced in the bone marrow. Protects and supports organs: Your skull shields your brain, your ribs protect your heart and lungs, and your backbone protects your spine.
Answer:
A. increase in American pika population size
Explanation:
Carrying capacity is the idea that relates to how much population can an environment sustain before collapsing. Here, the answer would be A. increase in American pika population size because if you increase the food for weasals, naturally the population carrying capacity goes up because now the environment has food to feed the weasals which can contribute to increasing the carrying capacity (i.e. the environment can now handle larger population of weasel than initial condition)
