Answer:
stromatolites
Explanation:
"stromatolites is a calcareous mound built up of layers of lime-secreting cyanobacteria and trapped sediment, found in Precambrian rocks as the earliest known fossils, and still being formed in lagoons in Australasia"
Ancient cyanobacteria present in stromatolites are considered as key factor for the increased amount of oxygen in atmosphere. Furthermore, these were considered as first organisms to trap carbon dioxide and release oxygen by the process of photosynthesis.
Answer:
It can significantly alter the homeostasis of the ecosystem
Explanation:
The trophic level is the position that occupies a given organism/ population/species in the food web. In a food web, the trophic levels are organized into a first category (formed by primary producers, e.g., plants), a second level (primary consumers, e.g., herbivores), and subsequent categories (predators, e.g., carnivores). The abrupt change in the number of organisms belonging to the same trophic level generally has a negative effect on the ecosystem by modifying the trophic structure of communities. For example, decreasing the number of producers will produce a decrease in the number of primary consumers, thereby altering the homeostasis (equilibrium) of the entire ecosystem. On some occasions, it may eventually lead to the extinction of populations and species.
The correct answer is A. Type I
Explanation:
In biology, a survivorship curve is a type of graphic that shows the rate of survival of individuals of one species along time. This type of graphics includes three types of curves. The first one or Type I occurs when individuals can survive during the first ages but by the middle and end of life, the survival rate falls. The second one or Type II occurs in species in which survival rate slowly declines as time passes. Finally, in the third curve or Type III, there are species that experience difficulties for surviving at the beginning of life by then survival rate stay the same. In the case of humans, most scientists classified our species in Type I because at early age survival rate is mainly high as only a few percentages of the population dies at a young age, but after middle age and in elderly the death rate sharps and therefore survival rate falls.
the third answer is the correct answer.
