Answer:
Selection is a directional process that leads to an increase or a decrease in the frequency of genes or genotypes. Selection is the process that increases the frequencies of plant resistance alleles in natural ecosystems through coevolution, and it is the process that increases the frequencies of virulence alleles in agricultural ecosystems during boom and bust cycles.
Selection occurs in response to a specific environmental factor. It is a central topic of population and evolutionary biology. The consequence of natural selection on the genetic structure and evolution of organisms is complicated. Natural selection can decrease the genetic variation in populations of organisms by selecting for or against a specific gene or gene combination (leading to directional selection). It can increase the genetic variation in populations by selecting for or against several genes or gene combinations (leading to disruptive selection or balancing selection). Natural selection might lead to speciation through the accumulation of adaptive genetic differences among reproductively isolated populations. Selection can also prevent speciation by homogenizing the population genetic structure across all locations.
Selection in plant pathology is mainly considered in the framework of gene-for-gene coevolution. Plant pathologists often think in terms of Van der Plank and his concept of "stabilizing selection" that would operate against pathogen strains with unnecessary virulence. As we will see shortly, Van der Plank used the wrong term, as he was actually referring to directional selection against unneeded virulence alleles.
The testes is where you will find them
The correct answer is E. Vertebrates are all related to a common ancestor
Explanation:
According to biology and evolution, organisms from different species but that share similarities in morphology (body structures) as well as in genetics often have a phylogenetic relationship which means they descend from the same organism or share a common ancestor. This applies to multiple taxonomical levels including classes such as mammals or birds as it has been proved each of this derived from a common ancestor. Therefore, the similarity in the body structure (morphology) in all mammals suggest vertebrates are related to a common ancestor and as they evolved from this, they share similarities not only in terms of morphology but also in genetics.
I believe it is a 2:1 ratio of hydrogen to oxygen, because the way i learned was that carbon hydrogen and oxygen have a ratio of 1:2:1, respectively.
Some of the physical properties of mineral are color, density, crystalline structure luster, odor and magnetism
