Life Processes
Exemplar MCQ 3
Which of the following is an incorrect statement?
- Organisms grow with time
- Organisms must repair and maintain their structure
- Movement of molecules does not take place among cells
- Energy is essential for life processes
Answer:(c) Movement of molecules does not take place among cells
The internal (cellular) energy reserve in autotrophs is
- Glycogen
- Protein
- Starch
- Fatty acid
Answer: (c) Starch [Plants store food in the form of starch]
Choose the event that does not occur in photosynthesis
- Absorption of light energy by chlorophyll
- Reduction of carbon dioxide to carbohydrates
- Oxidation of carbon to carbon dioxide
- Conversion of light energy to chemical energy
Answer: (c) Oxidation of carbon to carbon dioxide [Reduction of carbon dioxide releases oxygen which is utilised for making carbohydrates.]
The opening and closing of the stomatal pore depends upon
- Oxygen
- Temperature
- Water in guard cells
- Concentration of CO2 in stomata
Answer: (c) Water in guard cells [Entry of water in guard cells results in opening of stoma and reverse of it results in closing of stoma.
Choose the forms in which most plants absorb nitrogen
- Proteins
- Nitrates and Nitrites
- Urea
- Atmospheric nitrogen
- (1) and (2)
- (2) and (3)
- (3) and (4)
- (1) and (4)
Answer: (b) (2) and (3) [Protein is made by plants by utilising nitrogen. Plants cannot take up atmospheric nitrogen.]
Which is the first enzyme to mix with food in the digestive tract?
- Pepsin
- Cellulase
- Amylase
- Trypsin
Answer: (c) Amylase [salivary amylase from saliva is the first enzyme to mix with food.]
Which of the following statement(s) is (are) correct?
- Pyruvate can be converted into ethanol and carbon dioxide by yeast
- Fermentation takes place in aerobic bacteria
- Fermentation takes place in mitochondria
- Fermentation is a form of anaerobic respiration
- (1) and (3)
- (2) and (4)
- (1) and (4)
- (2) and (3)
Answer: (c) 1 and (4) [Fermenation is a form of anaerobic respiration whic takes place in cytoplasm and liberates ethanol/lactic acid and carbon dioxide.]
Lack of oxygen in muscles often leads to cramps among cricketers. This results due to
- Conversion of pyruvate to ethanol
- Conversion of pyruvate to glucose
- Non conversion of glucose to pyruvate
- Conversion of pyruvate to lactic acid
Answer: (d) Conversion of pyruvate to lactic acid [Accumulation of lactic acid in muscles results in muscle cramps.]
Choose the correct path of urine in our body
- kidney → ureter → urethra → urinary bladder
- kidney → urinary bladder → urethra → ureter
- kidney → ureters → urinary bladder → urethra
- urinary bladder → kidney → ureter → urethra
Answer: (c) kidney → ureters → urinary bladder → urethra
During deficiency of oxygen in tissues of human beings, pyruvic acid is converted into lactic acid in the
- Cytoplasm
- Chloroplast
- Mitochondria
- Golgi body
Answer: (a) Cytoplasm [Lactic acid is formed after anaerobic respiration in muscle cells and this happens in cytoplasm.]
Which of the following shows the correct equation for photosynthesis?
- 6CO2 + 12H2O → C6H12O6 + 6CO2 + 6H2O
- 6CO2 + H2O + Sunlight → C6H12O6 + O2 + 6H2O
- 6CO2 + 12H2O + Chlorophyll + Sunlight → C6H12O6 + 6O2 + 6H2O
- 6CO2 + 12H2O + Chlorophyll + Sunlight → C6H12O6 + 6CO2 + 6H2O
Answer: (c) 6CO2 + 12H2O + Chlorophyll + Sunlight → C6H12O6 + 6O2 + 6H2O