The three main parts of a nucleotide are a phosphate group, a five-carbon sugar (deoxyribose in DNA or ribose in RNA), and a nitrogenous base.
Phosphate Group: This is one of the essential parts of a nucleotide. The phosphate group consists of a phosphorus atom bonded to four oxygen atoms.
It provides a negatively charged backbone in the DNA or RNA molecule, contributing to its overall structure and stability.
Five-Carbon Sugar: The second vital component is a five-carbon sugar molecule. In DNA, this sugar is deoxyribose, while in RNA, it is ribose. The sugar forms the central part of the nucleotide structure and serves as a link between the phosphate group and the nitrogenous base.
Nitrogenous Base: The third crucial part is the nitrogenous base. There are four nitrogenous bases in DNA: adenine (A), thymine (T), cytosine (C), and guanine (G). In RNA, uracil (U) replaces thymine.
The nitrogenous base is responsible for the genetic code and base pairing in DNA (A pairs with T, and C pairs with G).
Therefore, all three components—phosphate group, five-carbon sugar, and nitrogenous base—are integral to the structure and function of nucleotides. None of them can be considered "not one of the main three parts" of a nucleotide.
For such a more question on nucleotide
#SPJ2
As succession proceeds in an ecosystem, there is an increase in population density. This is accompanied by the change in the species diversity as well. Thus, the correct option is B.
Ecological succession is the process through which the mixture of species and habitat in an area changes over the period of time. Gradually, these communities of species replace one another until a climax community like a mature forest is reached in that ecosystem, or until a disturbance, like a fire, occurs in that region.
The succession of an ecosystem begins with a pioneer species such as the lichens, some fungi species. Species such as the lichen begins to secrete acids which begin to break the barren land into a number of small particles. The small particles mix with the lichen species remains and starts the process of soil formation. On addition of the soil, more diverse plant species such as bryophytes and pteridophytes grow on the land. Later on, these plants are replaced by the most diverse angiosperm species. In this way, the species diversity tends to increase as a result of ecological succession.
Therefore, the correct option is B.
Learn more about Ecological succession here:
#SPJ6
Answer: B.
Explanation: Ecological succession, quite literally, is the change in the species of an area/ecosystem that had earlier been completely wiped out. Wildfires are a prime example of that.