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.
If there were no patterns in nature everything would be complicated. Atoms and all the little things would be different meaning our body structures would be different and the plants would be different too.
Answer:
Sulfur, phosphorous.... sedimentary cycle.
Carbon, oxygen and nitrogen.... gaseous cycle
The correct option is D.
Noble gases are very stable, because they have eight electrons in their outermost shells. This is called octet form. Other elements that do not have the octet form try to achieve the form by forming bonds with other elements. Because of their stability, noble gas are chemically inert, that is, they do not undergo chemical reactions with other elements.
Protons have a positive charge
Neutrons have a neutral charge
Electrons have a negative charge