(a) Work out the crosses so as to obtain the phenotypic ratios given below:

(i) 1 : 2 : 1 (in F2 generation)

(ii) 3 : 1 (in F2 generation)

(iii) 1 : 1 (in F1 generation)

(b) Differentiate between pleiotropy and polygenic inheritance patterns.

OR

(a) Describe the process of amino acylation.

(b) ‘‘Process of transcription and translation are coupled in prokaryotes, but not in eukaryotes.’’ Explain.

a) i) This would be observed in the case of Snapdragon. The cross can be depicted as:

ii) 3:1 is one of the most common phenotypic ratios and can be observed in the case of pea plant. The cross is depicted below.

iii) This can be observed in case of a test cross. The cross would be as follows:

b)

OR

a) Amino acylation is the activation of amino acids in the presence of ATP molecules that are linked to their cognate tRNA.

b)

• In bacteria mRNA does not required any processing to become active or functional.

• Transcription and translation take place in the same compartment as there is no separation of the cytosol and nucleus.

• Where as in Eukaryotes, the heterogenous m-RNA or hnRNA is transcribed which needs to undergo processing i.e. capping, tailing and splicing, to form functional m-RNA, which is then transported to cytoplasm, for translation.