Chromosome types and centrosome..

Protein infograph

Human skull

Blue print/marks distribution chart of class XI half yearly 2017

CLASS TEST FOR PRACTICE

Class XII                                                                                                Subject: Biology

Time: 40 Minutes                                                                                 Full Marks: 40

Q.1 what will be the number range of adenylate residue in tailing mechanism of hnRNA.

Q.2 what was the roll of H.G Khorana in the development of genetic code.

Q. 3 A cistron consist of 20 codons .how many amino acids will it code in the polypeptide transcribed ? why retro virus does not follow central dogma .explain.

Q.4 Recall the Griffith experiment if Rna instead of Dna was the genetic material,would the heat killed strain of streptococcus have transformed the R strain in to virulent.explain.

Q.5 lac operon is negatively regulated .what is meant by this?

Q.6 How a polypeptide chain synthesis terminated during protein synthesis. ?

Q.7 what are differences between template strand and coding strand?

Q.8 Give the differences   between repetitive DNA and Satellite DNA.

Q.9How Meselson and Stahal proved that replication of DNA are semi conservative.

Q.10give the enzymatic sequence of replication and a red eyed heterozygous female fruit fly is crossed with a red eyed male . work out all possible genotypes and phenotypes of the progeny.comment the pattern of inheritance.