Pigment-containing memberanous extensions in some cyanobacteria are
heterocysts
basal bodies
pneumatophores
chromatophores
D.
chromatophores
Cyanobacteria contain chlorophyll but the chlorophyll is not located in chloroplasts, rather it is found in chromatophores, infolding of the plasma membrane, where photosynthesis is carried out.
Heterocysts are specialised nitrogen fixing cells formed by some filamentous cyanobacteria such as Nostoc. A basal body is an organelle formed from a centriole and a short cylindrical array of microtubules.
Pneumatophores are lateral roots that grow upward for varying distance and function as the site of oxygen intake for the submerged primary roots.
Chromatophores are pigment-containing and light-reflecting cells, or groups of cells, found in a wide range of animals including amphibians, fish, reptiles, crustaceans and cephalopods.
Which one of the following cocci appears like grapes under microscope?
Streptococci
Diplococci
Staphylococci
Pneumococci
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
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
Which of these components is/are not present in Gram negative bacteria?
Teichoic acid
Pseudomurein
Lipopolysaccharide
Mycolic acid
Besides paddy fields, cyanobacteria are also found inside vegetative part of
Pinus
Cycas
Equisetum
Psilotum
Which of the following bacteria is observed as chain-like formation?
Escherichia coli
Bacillus subtilis
Streptococcus pyogenes
Micrococcus flavus
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
Which of the following are likely to be present in deep sea water?
Archaebacteria
Eubacteria
Blue-green algae
Saprophytic fungi
