Answer:
Nitrogen is present in the atmosphere in a molecule form about 78 percent. This nitrogen comes to the earth with the water through rainfall. Some nitrogen fix by beneficial microorganisms such as Cyanobacteria and Azotobactor which are present in the roots of higher plants. These microorganisms convert nitrogen molecule into nitrates and used by the plants. There are some other microorganisms which again convert nitrate into nitrogen molecules, called denitrifying bacteria and nitrogen molecule goes to the atmosphere again and complete the cycle.
Answer
C) Viruses need a host to survive
The correct answer is: Replacement of defective genes with normal genes
Recombinant DNA molecules are made in laboratory by the methods of genetic recombination such as molecular cloning. The aim of these methods is to bring together genetic material from different sources, creating “combinations” that usually couldn’t be found in the genome. The process of recombination is possible because, DNA molecules from all organisms share the same chemical structure (nucleotides are same among different species, difference is only in the nucleotide sequence).
<span>The chaparral is characterized by sparse, rough terrain and nutrient-poor soil meaning that no single resource is overly abundant. Therefore, a varied diet allows an animal to make use of a wider selection of the resources that are available to it and thereby thrive.</span>
Answer:
B. a sequence of DNA bases that duplicates a sequence of RNA bases.
Explanation:
Transcription is the first step in gene expression. It involves copying a gene's DNA sequence to make an RNA molecule.