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Answer:
a, b, c are correct
Explanation:
Enhancers are DNA sequences that increase the rate of transcription. Enhancers act as binding sites for transcription factors that stimulate the transcription of one or more genes and enhancers stimulate transcription for specific cell type or tissue in a specific manner. The possible reasons for the lack of enhancers in bacteria include.
Enhancers often provide a mechanism for cell-specific transcription of genes, and most bacteria lack differentiated cell types.
Bacterial operons make coordinate regulation of protein synthesis by enhancers unnecessary.
There is little to no intergenic space on bacterial chromosomes, which makes long-range-acting enhancer sequences unnecessary.
Therefore, the correct options are (a), (b), and (c).
Answer:
B) Nitrogen-fixing bacteria and lightning
Explanation:
Nitrogen cycle is the natural process in which atmospheric nitrogen is converted into nitrite and nitrate with the help of bacteria.
Nitrogen cycle is directly dependent on nitrogen-fixing bacteria and lightning.
As bacteria are responsible for most of the chemical conversion in the nitrogen cycle such as nitrogen fixation (first step) is done by soil bacteria (Cyanobacteria) that form ammonia, which is toxic to plants; nitrification in which ammonia is converted into nitrites and nitrates with the help of Nitrobacter and denitrification bacteria involve Pseudomonas, and Achromobacter which convert nitrite and nitrate into nitrogen.
The lightning breaks nitrogen molecules and allow it to combine with oxygen in atmosphere which further dissolve in rain and form nitrates.
Hence, the nitrogen cycle is most directly dependent upon nitrogen-fixing bacteria and lightning and the correct option is B.
Answer:
The correct answer is a gene
Explanation:
The DNA segment that carries information for coding one protein or polypeptide is called a gene. According to one gene-one polypeptide hypothesis, each gene is responsible for making a single chain of the polypeptide.
Originally it was said that one gene codes for one enzyme but later it was found that some gene also codes for non-enzyme proteins and single polypeptide chains. So after this research, the theory was modified and one gene-one polypeptide theory came. Therefore the right answer is gene.
The Outer ear. The pinna is the part you can see, and the ear canal is the part just inside of that :)
