A bryophyte which harbours a nitrogen fixing blue-green alga in its thallus is :
Pogonatum
Riccia
Marchantia
Anthoceros
Chiasmata are most appropriately observed in meiosis during :
diakinesis
diplotene
metaphase II
pachytene
In case of C4 plants the acceptor of CO2 is-
Phosphoglyceraldehyde
Ribulose monophosphate
Phosphoenol pyruvate
Ribulose diphosphate
Good soil is :
which holds whole of the water that enters into it
which allows percolating the water slowly from it
which allows water to pass very quickly from it
which allows limited amount of water to retain into it
A metal ion involved in stomatal regulation is :
iron
potassium
zinc
magnesium
B.
potassium
Potassium ions are involved in the stomatal movement. Alongwith negative ions, K+ ions accumulate in guard cells in response to light. Solute potential become more negative, resulting in entry of water by osmosis and the turgid guard cells. Therefore, the turgidity of guard cell open the stomata.
Starch is insoluble in water, yet it is accumulated in large quantities in potato tuber because :
it is useful for storage
tubers respire slowly
starch is synthesized in tubers
translocated sucrose is polymerized here
The first step in dark reaction of photosynthesis is :
formation of ATP
ionization of water
attachment of CO2 to a pentose sugar
excitement of electron of chlorophyll by a photon of light
The circinate vemation is the characteristic feature of ferns. It refers to :
coiling of young leaves
arrangement of leaves on stem
attachment of sori on leaves
heterophilly
Gymnosperms are called naked seed plants because these lack :
cotyledon
endosperm
ovary wall
testa