A. Silica
B. Calcium carbonate
C. Manesium carbonate
D. Both B. and C.
Biology
Empty diatom cells are called………..?
A. Raphe
B. Valves
C. Frustule
D. Girdles
Cell wall is extremely well preserved in fossil specimens in……….?
A. Diatoms
B. Dinoflagellates
C. Slime moulds
D. None of these
Unlike other algae, diatoms do not readily decay due to………..?
A. Nonliving cells
B. Siliceous wall
C. Mucilaginous wall
D. Water proof cell
The cell wall is usually composed of two overlapping halves called epitheca and hypotheca in……….?
A. Diatoms
B. Desmids
C. Pyrrophyta
D. Chlorophyta
Cell wall is richly impregnated with silica in……….?
A. Rhodophyta
B. Phaeophyta
C. Baciliariophyta
D. Euglenophyta
Microfossile often present in petroleum producing formationsare those of……….?
A. Diatioms
B. Heliozoans
C. Radiolarians
D. Foraminiferans
Centric discoid form of diatoms is……….?
A. Diplaneis
B. Coscinodiscus
C. Camphyloneiscus
D. Stephanodis
Diatoms are found in……….?
A. Phytoplanktonic population
B. Freshwater lakes and ponds
C. Marine environment
D. All of the above
Which one of the following is representing the group of diatoms?
A. Pinnularia, Navicula, Cymbella, Melosira
B. Euglenamorpha, Hedneria , Heteronema, Colacium
C. Nostoc, Anabaena, Aulosira, Cylindrospermum
D. Cochlodinium, Gymnodinium, Lenodinium, Peridinium