Answer:
In the course of evolution mammals are the animals which are evolved recently as compared to other groups such as fish, amphibians, or reptiles.
In addition, fur or hairs on body, mammary glands, middle ear bone, warm-blood, et cetera are the characteristics of mammals.
These characteristics were evolved during the course of evolution; they were not present in ancestral organisms.
However, tail, gill pouches, et cetera are characteristics of our ancestral groups. Thus, characters can be sometimes observed in mammals.
But mammals characteristics can not be observed in organisms which were evolved before mammals such as fishes, amphibians, reptiles, et cetera.
Answer:
Unconditioned stimulus.
Explanation:
Classical conditioning may be defined as a type of learning procedure in which the biological procedure is used to pair up with the previous nerve stimulus. This stimulus result in the response of an individual.
The Pavlov experiment with the dog explains the process of classical conditioning. The ringing of bell (conditioned stimulus) is paired with unconditioned stimulus (meat presentation).
Thus, the meat presentation is unconditioned stimulus.
Sporozoites that have undergone radiation. The PfSPZ vaccine has been in development by the company. The premise of the vaccine is use to use these radiated sporozoites inside the body to bring forth an attack on the sporozoite, which will help the body prevent itself against further attacks of malaria. Due to its promising nature, the U.S FDA department granted it the fast track designation in 2016.
