Answer:
B) There is an increase in the number of giraffes with long necks in areas of Africa where low-growing trees have died
Explanation:
The directional selection is one of the ways of the natural selection in which the natural selection selects or favours the most extreme trait of the species and the extreme trait show higher fitness than the normal or average trait.
In the given question, the case of Giraffe necks shows directional selection as the normal length of the neck is not favoured by the environment but the extreme trait that is long neck is favoured by the environment and the selection shifted to that level.
Thus, Option-B is the correct answer.
The answer is C. (The second B).
Because, Bacteria are key to recombinant DNA technology because of one simple fact. The reproduce rapidly.
Answer:
Exposure to a virus is closely related to the development of immunity, since the immune system is responsible for creating antibodies in response to the presence of potentially harmful biological agents, such as these viruses.
Explanation:
Viruses are biological agents that can produce diseases when they enter the body of a living being.<u> In response to contact with a virus, the</u><u> immune system</u><u> synthesizes specific </u><u>antibodies</u> to combat the foreign biological agent.
Antibody immunity can be of two types. It is fast when it is mediated by immunoglobulins M (IgM), which attack the virus anywhere, while the late and prolonged response is due to the development of immunoglobulins G (IgG).
An example of immunity to a virus occurs with the exhibition to the virus of the Dengue, that creates permanent immunity to the viral serotype to which an individual is exposed.
The acquired immunity, mediated by antibodies, is the base for the development of vaccines.
'The Fetus' would be the correct answer.
Answer:
A. Object A but not Object B
Explanation:
Speed = distance/time
A straight slanting line indicates a constant speed.
A horizontal line means that the distance is not changing, that is, the object has stopped.
The graph for Object B shows that it starts and stops repeatedly.
