Lack of oxygen in muscles often leads to cramps among cricketers. This results due to
(a) conversion of pyruvate to ethanol
(b) conversion of pyruvate to glucose
(c) non conversion of glucose to pyruvate
(d) conversion of pyruvate to lactic acid
Which of the following statement(s) is (are) correct?
(i) Pyruvate can be converted into ethanol and carbon dioxide by yeast
(ii) Fermentation takes place in aerobic bacteria
(iii) Fermentation takes place in mitochondria
(iv) Fermentation is a form of anaerobic respiration
(a) (i) and (iii) (b) (ii) and (iv)
(c) (i) and (iv) (d) (ii) and (iii)
Which is the first enzyme to mix with food in the digestive tract?
(a) Pepsin
(b) Cellulase
(c) Amylase
(d) Trypsin
Choose the forms in which most plants absorb nitrogen
(i) Proteins
(ii) Nitrates and Nitrites
(iii) Urea
(iv) Atmospheric nitrogen
(a) (i) and (ii) (b) (ii) and (iii) (c) (iii) and (iv) (d) (i) and (iv)
The opening and closing of the stomatal pore depends upon
(a) oxygen
(b) temperature
(c) water in guard cells
(d) concentration of CO2 in stomata
Choose the event that does not occur in photosynthesis
(a) Absorption of light energy by chlorophyll
(b) Reduction of carbon dioxide to carbohydrates
(c) Oxidation of carbon to carbon dioxide
(d) Conversion of light energy to chemical energy
Which of the following equations is the summary of photosynthesis?
(a) 6CO2 + 12H2O → C6H12O6 + 6O2+ 6H2O
(b) 6CO2 + H2O + Sunlight→ C6H12O6 + O2+ 6H2O
(c) 6CO2 + 12H2O + Chlorophyll + Sunlight→ C6H12O6 + 6O2+ 6H2O
(d) 6CO2 + 12H2O + Chlorophyll + Sunlight→ C6H12O6+ 6CO2+ 6H2O
The internal (cellular) energy reserve in autotrophs is
(a) glycogen
(b) protein
(c) starch
(d) fatty acid
Which of the following is an incorrect statement?
(a) Organisms grow with time
(b) Organisms must repair and maintain their structure
(c) Movement of molecules does not take place among cells
(d) Energy is essential for life processes