Life Science(Biology)

   Carl Woese, an American microbiologist, and others proposed Three Domain System in 1977on the basis of: (a) phylogenetic analysis of 16S rRNA, (b) cell's membrane structure and (c) sensitivity to antibiotics.    The three domains of life are: (i) the Archaea (archaebacteria ), (ii) the Bacteria (eubacteria) and (iii) the Eukarya (eukaryotes). This domain is again divided into 4 kingdoms: (a) Protista, (b) Fungi, (c) Animalia and (d) Plantae. Characters of Domain Archaea:   1. Members can live in different habitats:  (i) in the rumens and termites as anaerobic methanogens , (ii) in extreme saline condition as halophiles which require NaCl , (iii) in thermal vents and hot springs (above 100°C) as thermophiles and (iv) as thermoacidophiles   in both hot and acidic environments. 2. Cell structure is prokaryotic type. 3 . Size : 0.1 micro my to 1.5 micro my in diameter, if filamentous 200 micro my in length. 4. May be gm+ or gm--. 5. Some members ...

     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.          ...

Q Role of microbes in medicine industry.                                       (Word limit 150) Answer : Antibiotics/ wonder drugs: About 2100 antibiotics have been reported from actinomycetes,  of which 1922 come from Streptomyces e.g., Antibiotic.              Source.         Target 1 Streptomycin.  //  S . griseus. //  Gm+                                                        bacteria                                               Mycobacterium                              ...

Q .Compare the characters of Caesalpiniaceae, Mimosaceae &  Fabaceae.  Mention few pulse-yielding plants.                               8+2=10, 4th Paper, 2012,TU. 2008 Syllabus Answer: 1 Leaves:        Caesalpiniaceae..... Paripinnate        Mimosaceae........... Bipinnate        Fabaceae................ Imparipinnate  2 Infloresences        Caesalpiniaceae.....Raceme or panicle or rarely cymose.         Mimosaceae......... Spike  ( e.g. Dicrostachys ) or head-like globose spike         Fabaceae..............Raceme, panicle (e.g. Dalbergia ),dense axillary head(e.g. Trifolium), solitary ( e.g. Lathyrus ). 3 Flower:     Caesalpiniaceae.... Slightly zygomorphic     Mimosaceae.........  Actinomorphic and regular.     Fabaceae............

Male Papaya Plant: Photograph : A male papaya plant Description:   The plant is a herb with milky latex, crown of leaves present terminally. Leaves:   Large, long petioled, simple,lobed, exstipulate . Photogrsph: Male Infloresences: Description: Axillary panicles Photograh:A male flower Description: Incomplete, actinomorphic . Photohraph: A part of male flower showing calyx, corolla tube & pedicel Description: Calyx:  Sepals (5) ,cupular, rotate, shortly segmented, gamosepalous,  valvate. Photograph: Twisted corolla in male flower with epipetalous stamens Description: Corolla-  Petals (5) , gamopetalous,tubular below but expanded at apex, twisted in aestivation.  Photograph : Androecium in male flower Stamens -  5+5, arranged in two whorls, inserted at the throat of the corolla tube ; anther bithecous, dorsifixed, connective turns ligulate. Pistilode in male flower is...