What effect does the loss of a species have on an ecosystem (all living organisms and natural features in an area)?

After all, most species have become extinct during the history of life on Earth.
As you explore this week’s resources, you look at how the loss of one species can affect the survival of other species. Biologists who study ecology have discovered that the decrease or loss of some species has a much greater impact on an ecosystem than the decrease or loss of other species. Species that have a stronger influence within their ecosystems are known as keystone species.

Post in paragraphs as follows:

Describe the endangered or threatened species you have selected. Include where the species lives.
Discuss whether you think this species is important or worth saving.
Explain why or why not.
Explain what determines the worthiness of a species.

How can each be described in the behavior of chromosomes during meiosis? Which applies to which stage(s) of meiotic cell division? 3. Be familiar with the following genetics terminology: Gene, locus, allele, dominant, recessive phenotype, genotype, heterozygous, homozygous, testcross, carrier, penetrance, pleiotropic, polygenic, continuous variation, epistasis, multifactorial, complete dominance, incomplete dominance, co-dominance. How does Tay-Sachs disease illustrate that a single trait can exhibit complete, incomplete, and co-dominance?

How is X-linked gene dosage regulated in mammals? What are the consequences of these adjustments in gene dosage? How can this result in things like calico cats? Know how to calculate recombination frequency.

Which are more abundant in gamete populations? Why? What is recombination frequency? How is the frequency of recombinant offspring in populations used to tell the distance between linked genes (how is it practically applied to map genes)?