Answer:
In an ancestral elm species, mutations gave rise to the phenotypic trait "winged-seeds". Subsequently, selection favored elm plants with winged-seeds that diverged over time to become a separate species
Explanation:
A mutation is a genetic change in the DNA sequence. In general, mutations have a negative impact on the fitness of the individual (i.e., mutations are generally deleterious) and therefore they disappear from the population. However, there are situations where mutations are beneficial and confer an adaptive advantage, thereby increasing their frequency in the population. In this case, mutations associated with the formation of winged-seeds conferred an adaptive advantage (i.e., higher seed dispersal capacity) to individuals who had this phenotypic trait, thereby these individuals had more chances to reproduce and pass their genes to the next generation. Eventually, Elm plants with winged-seeds accumulated sufficient genetic differences to prevent interbreeding, leading to the formation of a separate species.
Answer:
Ribosomes
Explanation:
No matter where mitochondrial proteins are made, they are synthesized on Ribosomes that translate messenger RNA into the amino acids that form the protein chain. Most of the proteins in mitochondria function in genome regulation, DNA maintenance, and upkeep of the small percentage of internal mitochondrial proteins.
D. Calcium cycle
Biogeochemical cycles are not an important part of the Earth system.
Answer:
D. climax communities
Explanation:
The climax communities are the communities that have reached equilibrium. This basically means that there's the optimal number of species of flora and fauna, as well as the optimal populations of them in the ecosystem. They all interact and are perfectly adapted to coexist, benefit from one another, and balance the usage of food sources with its renewing. This type of communities appear at places where there has been no disturbances for quite some time, so the species lving there managed to create a perfect balance.