In a hypothetical situation, a certain species of aphid feeds only on sugar maple trees. In forests of the eastern United States
, sugar maples are only one of a number of different tree species. If some of the aphids develop a strong preference for feeding on Black Walnut trees and mate only with other aphids that prefer black walnut trees, then over time, which of the following processes should occur. (Remember, the host species can be considered the aphids' "habitat."): 1.reproductive isolation 2.allopatric speciation 3.habitat isolation 4.prezygotic barriersv
Options for the questions are not given. They are as follows :
A ) 1,2,3
B) 2,3
C)1 ,3, 4
D)1
E) 1 through 4
Answer:
C) 1,3,4
Explanation:
Some aphids make black walnut trees their habitat in the forest and only prefer to mate with aphids who have the same habitat. This is an example of reproductive isolation since these aphids now have different mating preferences and hence are isolated from rest of the aphids. The isolation occurred on the basis of difference in habitats so it is also an example of habitat isolation. Since the mating is prevented all together it is also an example of prezygotic barrier i.e. formation of zygote is inhibited. However, it is not an example of allopatric speciation since the aphids are not separated geographically from each other. They are present in the same area but have different habitat preference. Hence, option C is correct answer.
They are found only in the zone of maturation, and not the zone of elongation, possibly because any root hairs that arise are sheared off as the root elongates and moves through the soil. Root hairs grow quickly, at least 1μm/min, making them particularly useful for research on cell expansion.
If you ate a cookie while you were upside down, your body would try it's best to bring the food to the stomach. There are other forces other than gravity that will help the cookie get to the stomach.
