I think the correct answer from the choices listed above is the first option. The abiotic component that would most likely change in a shallow ocean ecosystem during upwelling would be an increase in oxygen content. Hope this answers the question. Have a nice day.
The experts calculate that between 0.01 and 0.1% of all species will become extinct each year. If the low estimate of the number of species out there is true - i.e. that there are around 2 million different species on our planet - then that means between 200 and 2,000 extinctions occur every year.
What is extinction?
- Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species.
- The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the fossil record) after a period of apparent absence.
- More than 99% of all species that ever lived on Earth, amounting to over five billion species, are estimated to have died out.
- It is estimated that there are currently around 8.7 million species of eukaryote globally, and possibly many times more if microorganisms, like bacteria, are included. Notable extinct animal species include non-avian dinosaurs, saber-toothed cats, dodos, mammoths, ground sloths, thylacines, trilobites and golden toads.
- Through evolution, species arise through the process of speciation—where new varieties of organisms arise and thrive when they are able to find and exploit an ecological niche and species become extinct when they are no longer able to survive in changing conditions or against superior competition.
- The relationship between animals and their ecological niches has been firmly established.
- A typical species becomes extinct within 10 million years of its first appearance, although some species, called living fossils, survive with little to no morphological change for hundreds of millions of years.
To learn more about extinction: brainly.com/question/14482178
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How are we to know the answers without knowing about which groups the question pertains.
Answer:
The nuclear receptor superfamily comprises a large group of transcription factors that play a key regulatory role in development and homeostasis of multicellular organisms. A special feature of nuclear receptors is their ability to bind to condensed chromatin templates, which makes them important initiators of gene transcription. Moreover, the ability of nuclear receptors to sequentially recruit a variety of transcription factors and coregulators to target promoters and to orchestrate the whole process of gene transcription confirms their biological significance and stimulates intensive research and a high level of scientific interest in this field. In this review, we summarise current knowledge regarding the structure and function of nuclear receptors as principal regulators of gene expression. Emphasis is given to the molecular mechanisms of nuclear receptor-mediated transcriptional activation and repression including recent progress made in this area.
