polyp should be the answer
Answer:
B. Hominins evolved an opposable thumb that enabled hands to grasp objects.
Explanation:
Prehistoric hominids evolved opposable thumbs earlier than bipedal walking. The opposable thumbs have been critical during evolution because this position enables the digits to grasp and handle objects.
Answer:
This study was focused on an Ecosystem level, as it involved soil properties and above-ground vegetation interacting with mentioned soil physic properties.
Explanation:
Ecological studies can be performed at different hierarchy levels:
- <u>Organism</u>: This is an individual physiologically independent from other individuals. At this level, it must be understood <em>how an organism survives</em> under certain changing <em>physic and chemistry conditions</em>, and how it <em>behaves</em> to reproduce, avoid predators, and find food.
- <u>Population</u>: Groups of individuals from the same species, with similar characteristics, capable of crossing, leaving offspring that live in the same habitat at the same time. At this level, it is interesting to know the <em>size of the population required to leave fertile offspring</em> that ensure the population will <em>survive over time</em>. It is also interesting to know <em>genetic variability </em>that allows <em>evolutive adaptation </em>to environmental changes.
- <u>Community</u>: Relationship or interaction between different species groups that live in the same habitat and at the same time. At this level, it is interesting to study <em>inter-specific interactions</em> that could cause <em>changes in the populations´ size</em>. These could be the cases of competition, predation, parasitism, mutualism, and etcetera.
- <u>Ecosystem</u>: Basic interaction unit between population and environment that turn in complex relations existing between living and non-living elements in a given area. In the example, interactions between recovering vegetation and soil properties, as non-living elements.
