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.
Answer:
This statement is False.
Explanation:
A shared apo-morphy which differentiate a clade from other organisms is called synapomorphy. In simple words, members of monophyletic group shares an apomorphy which indicate the presence or absence of certain organs from clade.
For example, loss of legs in snakes is an important synapomorphy.
When the food hits our tongues it triggered saliva (chemical digestion) then our mouths chewing is mechanical. So therefor your answer is The Mouth. Hope this helps <3