A column of water within xylem vessels of tall trees does not break under its weight because of
Dissolved sugars in water
Tensile strength of water
Lignification of xylem vessels
Lignification of xylem vessels
B.
Tensile strength of water
A column of water within xylem vessels of tall tree does break under its weight because of high tensile strenght of water, i.e. an ability to resist a pulling force. This high tensile property depends on cohesion, adhesion and surface tension property of water. Due to these forces only transpiration drive ascent of xylem sap occurs.
Human urine is usually acidic because
The sodium transporter exchanges one hydrogen ion for each sodium ion, in peritubular capillaries.
Excreted plasma proteins are acidic
potassium and sodium exchange generates acidity
potassium and sodium exchange generates acidity
The enzyme that is not present in succus entericus is
maltase
nucleases
nucleosidase
nucleosidase
In which group of organisms the cell walls form two thin overlapping shells which fit together?
Chrysophytes
Euglenoids
Dinoflagellates
Dinoflagellates
In photosynthesis, the light-independent reactions take place
Thylakoid lumen
Photosystem I
Photosystem II
Photosystem II
Among china rose, mustard, brinjal, potato, guava, cucumber, onion and tulip, how many plates have superior ovary?
Five
Six
Three
Three
Name the pulmonary disease in which alveolar surface area involved in gas exchange is drastically reduced due to damage in the alveolar walls.
Pleurisy
Emphysema
Pneumonia
Pneumonia
In mammalian eye, the 'fovea' is the center of the visual field, where
high density of cones occur, but has no rods.
the optic nerve leaves the eye.
only rods are present
only rods are present
Pick up the wrong statement
Cell wall is absent in Animalia
Protis ta have photosyn thetic and heterotrophic modes of nutrition
Some fungi are edible
Some fungi are edible
The primary dentition in human differs from permanent dentition in not having one of the following type of teeth
Canine
Premolars
Molars
Molars
