Answer:
Option-C
Explanation:
Desertification refers to the formation of barren land from the arid land due to many factors which could be climatic or anthropogenic. The climate factors include no rainfall, arid conditions, less water and water bodies, overgrazing by animals and many others.
As a result of these factors, the plants die or are unable to hold the soil. This leads to loosening of soil which causes soil erosion. This converts the fertile land into infertile land and the land becomes barren.
Thus, desertification is the correct answer.
Eukaryotic organisms that cannot be classified as a plant, animal, or fungus.
The correct answer is a eukaryote. While it would be an impulse to answer prokaryote since the first thing that will come to our minds if we deal with a microorganism that thrives in extreme environments (i.e. hot thermal vents) will be archea, which are prokaryotes. But in this case, it is clearly specified that the single-celled organism has a nucleus which is the characteristic feature of eukaryotes.
Bacteria is incorrect as bacteria are prokaryotes. Plant is incorrect as all plants are multicellular organisms.
Answer:
Histone acetylation or DNA methylation.
Explanation:
The epigenetics may be defined as the genetic phenomena that might cause mutation in the organism's genome. The DNA sequence of the organisms do not get changed in epigenetics.
This phenomena is limited whether the gene is herited from the mother ot the father. The phenomena like acetylation of histones increase the gene expression. The DNA methylation and histone deacetylation at specific residues reduces the gene expression.
Thus, the answer is histone acetylation or DNA methylation.