Which of the following statements is/are correct for transduction?
It is observed in Gram positive and Gram negative bacteria.
Bacteria should be in state of competence
Transfer of DNA by a bacteriophage takes place.
Packaging of both host and phage DNA takes place
A.
It is observed in Gram positive and Gram negative bacteria.
C.
Transfer of DNA by a bacteriophage takes place.
D.
Packaging of both host and phage DNA takes place
Transduction is a type of sexual reproduction in bacteria whether it be Gram positive or Gram negative bacteria. It is a process by which DNA is transferred from one bacterium to another by a virus (bacteriophage)involves degradation of host DNA by phage enzymes. B-cell synthesises new phages that incorporate phage DNA and some host DNA also. For transduction to take place, there is no need for the host cell (bacteria) to be component.
Besides paddy fields, cyanobacteria are also found inside vegetative part of
Pinus
Cycas
Equisetum
Psilotum
Pigment-containing memberanous extensions in some cyanobacteria are
heterocysts
basal bodies
pneumatophores
chromatophores
Which of the following are likely to be present in deep sea water?
Archaebacteria
Eubacteria
Blue-green algae
Saprophytic fungi
Which of the following bacteria is observed as chain-like formation?
Escherichia coli
Bacillus subtilis
Streptococcus pyogenes
Micrococcus flavus
Which one of the following cocci appears like grapes under microscope?
Streptococci
Diplococci
Staphylococci
Pneumococci
Which of these components is/are not present in Gram negative bacteria?
Teichoic acid
Pseudomurein
Lipopolysaccharide
Mycolic acid
The metrics described by whittaker which takes into account the number of species and their eveness is
Shannon index
Beta diversity
Species richness
Simpson index
The heterocysts in the cyanobacterium are
site of photosynthesis
reserve food storage
enactive enzymes
nitrogen-fixation
Study the following Coloumns and match correctly.
| Column I | Column II |
| A. Siphonogamy and zooidogamy | 1. Amphibians of plant kingdom |
| B. Living fossil | 2. Arachis |
| C. Liverworts | 3. Ginkgo |
| D. Double fertilisation |
4. Cycas 5. Laminaria |
The correct answer is
A - 4; B - 5; C - 2; D - 1
A - 2; B - 4; C - 1; D - 3
A - 4; B - 3; C - 2; D - 1
A - 4; B - 3; C - 1; D - 2
