Multiple Choice QuestionsWhich one of the following structures between two adjacent cells is an effective transport pathway?
Plasmodesmata
Plastoquinones
Endoplasmic reticulum
Endoplasmic reticulum
In unilocular ovary with a single ovule, the placentation is
marginal
basal
free central
free central
An element playing important role in nitrogen fixation is
Molybdenum
copper
manganese
manganese
A.
Molybdenum
Molybdenum is absorbed as molybdate by plants. It is involved in nitrogen metabolism including nitrogen fixation. It is a component of enzyme nitrogenase and acts as an enzyme activator. Its deficiency cause chlorosis and necrosis, whiptail of cauliflower and premature leaf fall.
Copper is absorbed by the plant in ionic form. Its deficiency causes necrosis, die back in Citrus, reclamation in legumes.
Manganese is absorbed by the plants as a bivalent ion. It acts as the enzyme activator. Its deficiency causes interveinal chlorosis as well as yellowing of starch and their subsequent degenerate.
Zinc is needed for biosynthesis of IAA and also acts as the enzyme activator. Its deficiency causes chlorosis, little leaf, rosette, the white bud of maize and mottling of leaves.
One example of animals having a single opening to the outside that serves both as mouth as well as anus is
Octopus
Asterias
Ascidia
Ascidia
The chief water conducting elements of xylem in gymnosperms are
vessels
fibres
tansfusion tissue
tansfusion tissue
Membrane -bound organelles are absent in
Saccharomyces
Streptococcus
Chlamydomonas
Chlamydomonas
The kind of epithelium which forms the inner walls of blood vessels is
cuboidal epithelium
columnar epithelium
ciliated columnar epithelium
ciliated columnar epithelium
Which one of the following has its own DNA?
Mitochondria
Dictyosome
Lysosome
Lysosome
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