Just think about cancer.. it's uncontrolled cell growth, so mutations in genes can cause cancer by accelerating cell division. As the cells contribute to grow they then develop as a tumor.
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.
well when they were around that was decades and centuries ago so the bones have probably deteriorated from being pushed so far down in the earth
Your answer is A. gene flow
Answer:
c. Aa Bb
Explanation:
The parents were pure breeding with genotypes AAbb and aaBB. A cross between AAbb and aaBB would produce AaBb genotypes in F1 progeny. Two F1 strains would be crossed to produce F2 progeny. The F2 progeny would have the genotype ratio= 1:2:1:2:4:2:1:2:1.
Out of all the obtained genotypes in the F2 generation, the proportion of "AaBb" genotype was 4/16. Therefore, "4" in the given ratio represents the genotype "AaBb".
