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The second A is known as the reversal phase in which the intervention is withdrawn to see if the target behavior returns to the baseline behaviour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:
Nitrogen is an essential nutrient for plants and a significant component of proteins, which all animals need to grow, reproduce and survive. The nitrogen cycle converts nitrogen into compounds that plants and animals can use. Humans and Animals Need Nitrogen All human tissue – muscles, skin, hair, nails and blood – contains protein.
<span>Antibodies. A. k.a. immunoglobulins. They are produced by a group of white blood cells called B lymphocytes (or B cells). There are 5 classes of immunoglobulins; IgM,IgA,IgE,IgG and IgD.The classes of antibody diifferent both in their constant region and in their activity.IgG, the most common antibody, and is found mostly in the blood and tissue fluids, and IgA is localized in the mucous membranes which line the respiratory and gastrointestinal tracts.</span>
<span>The answer is scavengers. Scavenging is both a meat eating and a herbivorous sustaining conduct in which the forager bolsters on the dead creature and plant material present in its natural surroundings. The eating of flesh from similar species is alluded to as savagery.
A few vertebrates are scavengers. Hyenas are regularly thought of as scavengers, but on the other hand are conventional carnivores. A solitary hyena bolsters for the most part on dead creatures. Hyenas may devour a creature that has passed on to wounds, or it might take meat from another flesh eater, for example, a lion.</span>
