Biological Classification Test - 3

Zoospore is an asexual spore produced by certain algae and some fungi, capable of moving about by means of flagella.

Diatomaceous earth is formed from large amounts of cell wall deposits left behind by diatoms in their habitat. Diatoms are chrysophytes.

Euglena has a protein rich layer in place of cell wall called pellicle which gives flexibility to its body. Gonyaulax has red pigments which is the cause of red tides, Diatoms have siliceous cell walls, thus the cell walls are indestructible. Slime molds, under suitable conditions, form an aggregation called plasmodium which may grow and spread over several feet.

The infectious agent of potato spindle tuber disease is free RNA. This free RNA is called viroid.

M. W. Beijerinck, in 1898, demonstrated that the extract of the infected plants of tobacco could cause infection in healthy plants. He called the fluid 'Contagium vivum fluidum' meaning 'infectious living fluid'.

Euglena is a photosynthetic autotroph in presence of sunlight, but it is a heterotroph in absence of light.

Nuclear membrane is found in all eukaryotes.

Claviceps belong to ascomycetes group in which asexual spores are conidia, produced exogenously on the special mycelium called conidiophores. Colletotrichum belongs to Deuteromycetes group that reproduces only by asexual spores known as conidia.

Heterocysts are specialised cells borne by photoautotrophs (photosynthetic autotrophs) like nostoc for nitrogen fixation.

In fungi ascomycetes and basidiomycetes, an intervening dikaryotic stage (n + n i.e. two nuclei per cell) occurs; this phase is called dikaryophase of fungus.