Medullary rays are tissues made up of
phloem parenchyma
xylem parenchyma
sieve tube
sclerenchyma
B.
xylem parenchyma
Medullary rays are the vertical plates of parenchyma cells running radially through the cylinder of vascular tissue in the stems and roots of plants. Each may be one to many cell in width.
Primary medullary rays occur in young plants and in those not showing secondary thickening. They pass from the cortex to the pith.
Secondary medullary rays are produced by the vascular cambium and terminate in xylem and phloem tissues. Medullary rays store and transport food materials.
Nitrogenase enzyme is a
magnesium-iron protein
molybdenum-iron protein
iron-copper protein
nickel-iron protein
Which one of the following matching pairs is incorrect?
Shell fish - Pisces
Silver fish - Arthropoda
Cuttle fish - Mollusca
Star fish - Echinodermata
Necrosis (die-back) ofthe tip of young leaves is caused due to the deficiency of
iron
manganese
zinc
copper
Which one of the following enzymes is responsible for the conversion of norepinephrine to epinephrine?
Catecholamine-O-methyltransferase
Phenylalanine-N-methyltransferase
DOPA decarboxylase
Monoamine oxidase
Guttation is a process of loss of water in
liquid form containing dissolved minerals
liquid form without dissolved minerals
vapour form with minerals
vapour form without minerals
An allosteric inhibitor of the enzyme acts by binding to the
substrate
product
catalytic site of the enzyme
non-catalytic site of the enzyme
Which one of the following matching pairs is incorrect?
Mollusca - Pseudocoel
Cnidaria - Nematocyst
Annelida - Chloragogen cells
Echinodermata - Water vascular system
