Life Science(Biology)

     The permanent alteration in  sequences of nitrogen bases in the DNA by   (i) deletion ,  (ii) insertion ,   (iii) inversion and  (iv) substitution (transition / transversion) is called as mutation .      If a purine of a DNA is substituted by another purine   or a pyrimidine by another pyrimidine , then the phenomenon is then termed as transition .   e.g. AT is replaced by GC and vice versa.     When a purine  of a DNA is substituted by a pyrimidine  and vice versa is called as transversion.     e.g. GC is replaced by CG and vice versa.                                 and             AT  is replaced by TA and vice versa.     Note :  Transitions are more frequent than Transversion . UV as a Physical Mutagen: Though UV is non-ionising , it is a kind of...

PARAMECIUM Systematic position: Phylum:.          Protozoa Subphylum.    Cilliophora Class.              Ciliata Subclass.        Holotrichia Order.              Hymenostomatida Genus.            Paramecium  Species.          caudatum                          aurelia                           multimicronucleatum                          bursaria                          calkinsi                          woodruffi                    ...

TDP(General)1st Semester Exam.,2015                         Full Marks: 40                         Time :2 hours Candidates are required to give their answers in their own words as far as      practicable 1.(a) (i) Classify cytoskeleton.  (ii) Describe the structure of mitochondria. (iii) What is osteoporosis?          4+5+1=10                            Or (b) (I) What is apoptosis? (ii) Discuss active transport mechanism with example. (iii) Differentiate between smooth muscle and skeletal muscle.                    2+5+3=10 2.(a) (I) What is viscosity? State it's physiological significance. (ii) What is protective colloids? (iii) Explain Henderson-Hasselbalch equation.          ...