Answer:
The correct answer is option-C
Explanation:
Anastosomes is a connection between the two interconnected tubular structures like in the loops of intestine or the blood vessels.
The anastomy between the blood vessels is known as the circulatory anastomosis. The connection is formed between the arteries and arteries or between veins and veins or between arteirs and veins.
The anastosome connections forms the bypass route for the flow of blood if one pathway of blood id blocked.
Thus, option-C is the correct answer.
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.
Answer:
I) Sexual reproduction
II) Mutation
Explanation:
Variations refer to the difference observed within organisms of the same species. Variation are introduced into a population by:
- new genetic combinations that occur during sexual reproduction (i.e during meiosis)
- mutations, spontaneous changes that occur in genes and chromosomes.
Answer:
Color is the least reliable property for mineral identification. The same mineral can come in a variety of colors and different minerals can be the same color. The color can change over time do to weathering.
Explanation:
After mining, to reclaim the land, the depression is filled with rocks then the top is filled with loosely graded soil. Introduction of early succession plants is important before big trees can grow. The early succession plants help in the breaking down of the rocks into soil hence making the topsoil deeper to support trees.
