The correct answer is option D, difficulty of redesigning workable ecosystems
Reason -
The area that was redesigned into an ecosystem actually failed to attract the endangered species of clapper rails in California because of the following two reasons –
a) Failed attempt of restoration of Cord grass ( a tree which is a dominant tree in the nesting habitat of clapper rail) . Even if few such trees were there they could not grow to their full height and thus were incapable of providing adequate nesting cover
b) Due to the lack of predatory insect, some herbivore insect in the ecosystem attacked the green grasses thereby making the nesting inadequate.
Answer:
Option A, oxygen in the atmosphere
Explanation:
The highest level of oxygen reached during this phase of the geological cycle of earth. The oxygen level in Carboniferous period accounted for 35% as compared to 21% of oxygen in the atmosphere in present time.
Due to high oxygen content, the giant and wide varieties of terrestrial animal and plant species evolved. For example – size of insects and carwlies increased, plant became extremely giant, increase in number of tree ferns etc.
Answer: Ecosystem
Explanation: An ecosystem consists of all the biotic and abiotic factors in an area and their interactions. A niche refers to the role of a species in its ecosystem. A habitat is the physical environment in which a species lives and to which it is adapted.
Answer:
<em>The correct option is limited food and water resources favored the survival of smaller deer.</em>
Explanation:
The islands where the Key deer lived had limited food and water resources. As migration was not possible for these species because the white-tailed deer had more adaptations as compared to them, hence they had to somehow survive in these areas with limited food and water resources. Limited food resources were the reason that the Key deer could not grow properly and hence evolved to have very little weight.