Question

1. What is the “central dogma” of biology?

2. What are the three differences between RNA and DNA?

3. What is the process of transcription?

4. Where does transcription occur? Why?

5. What are the three types of RNA? What do they do?

6. Explain the process of translation. How do the different types of RNA work together?

7. What is a codon?

8. How does a ribosome know where to start and stop translation?

Answer 1

Answer=

1.Central dogma of biology -Describes the two-step process transcription and translation ,by which the information in genes flows into proteins: DNA RNA protein.Transcription is the synthesis of an RNA copy of a segment of DNA.

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2.Differences between DNA & RNA

DNA	RNA
1.DNA is double stranded	1. RNA is single stranded.
2.Pentose sugar is deoxyribose	2.Pentose sugar is ribose.
3.It conatins bases,Adenine,Guanine,Thymine and cytosine.	3.It contains the bases Adenine,cytosine,guanine and Uracil.
4.Found in nucleus.	4.Found in nucleolus.

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3] The process of transcription = Transcription is the first step of gene expression in which the information in a strand of DNA is copied in messenger RNA by the enzyme RNA polymerase.

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4]The transcription occurs in the nucleus of the cell.because DNA is present in the nucleus.

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5.There are 3 types of RNA :

1.Messenger RNA (mRNA) -it carries the genetic information copied from DNA in the form of a series of three -base code words ,each of which specifies a particular amino acid.

2.tRNA - helps to decode a messenger RNA sequence into protein.

3.rRNA - helps to form ribosomes.These complex structures ,which physically move along an mRNA molecule,catalyses the assembly of amino acids into protein chains.