Planet closest to Sun?
A Venus B Mercury C Earth D Mars
Mercury is closest to Sun.
Vitamin C deficiency causes?
A Rickets B Scurvy C Night blindness D Beriberi
Scurvy from Vitamin C deficiency.
Hardest natural substance?
A Gold B Iron C Diamond D Quartz
Diamond = 10 on Mohs scale.
Gas causing global warming?
A Oxygen B Nitrogen C Carbon Dioxide D Hydrogen
CO₂ is main greenhouse gas.
Ohm Law: V = ?
A I/R B IR C I+R D I-R
Powerhouse of cell?
A Nucleus B Ribosome C Mitochondria D Lysosome
Mitochondria produces ATP.
Sound cannot travel through?
A Water B Steel C Vacuum D Air
Sound needs medium, not vacuum.
Universal blood donor group?
A A+ B B+ C AB+ D O-
O- has no antigens, universal donor.
Human body has how many bones?
A 200 B 206 C 210 D 198
Adult body has 206 bones.
Largest gland in human body?
A Pancreas B Thyroid C Liver D Kidney
Which of the following is the primary pigment responsible for absorbing light energy in the visible spectrum during photosynthesis?
A Chlorophyll a B Xanthophyll C Carotenoid D Anthocyanin
Chlorophyll a is the primary photosynthetic pigment that absorbs light in the blue and red regions of the electromagnetic spectrum.
The pH of cell sap in plant cells typically ranges between:
A 2-3 B 4-6 C 7-8 D 8-9
Plant cell sap is slightly acidic due to organic acids like malic acid and citric acid, maintaining pH between 4-6.
Which element is essential for the synthesis of chlorophyll molecule and forms the central atom in its structure?
A Iron B Magnesium C Zinc D Copper
Magnesium (Mg) is the central atom in the chlorophyll molecule, forming a coordinate bond with the porphyrin ring.
The phenomenon where plants bend towards light source is governed by which hormone?
A Gibberellin B Auxin C Cytokinin D Ethylene
Auxin causes differential elongation of cells on the shaded side, resulting in phototropic response towards light.
In C4 plants, the first stable compound formed during carbon fixation is:
A 3-Phosphoglycerate B Oxaloacetate C Ribulose-1,5-bisphosphate D Glucose
In C4 photosynthesis, CO2 combines with PEP (3-carbon) to form oxaloacetate (4-carbon compound) via the enzyme PEP carboxylase.
The root pressure phenomenon in plants can be measured using a device called:
A Potometer B Barograph C Manometer D Tensiometer
Root pressure is measured using a manometer connected to the cut end of a plant stem, showing the positive pressure generated by roots.
Which of the following statements about stomatal opening is correct?
A Guard cells lose turgor pressure when stomata open B Potassium ions accumulate in guard cells during stomatal opening C Stomata open in complete darkness D Guard cells have thick outer walls and thin inner walls
During stomatal opening, potassium ions (K+) actively accumulate in guard cells, increasing osmotic potential and causing water influx.
The phenomenon of leaf fall in deciduous plants before winter is regulated by which hormone?
A Abscisic acid B Ethylene C Gibberellin D Cytokinin
Abscisic acid (ABA) accumulates during water stress and environmental changes, promoting abscission layer formation and leaf fall.
In plant tissue culture, which growth regulator ratio promotes callus formation?
A High auxin : Low cytokinin B Low auxin : High cytokinin C Equal ratio of auxin and cytokinin D Neither auxin nor cytokinin
High auxin to low cytokinin ratio promotes callus formation, while the ratios determine the type of organogenesis.
The osmotic potential of a solution is directly related to:
A Temperature only B Solute concentration and temperature C Pressure only D Volume of solvent only
Osmotic potential (Ψs) = -iCRT, where it depends on solute concentration (C) and absolute temperature (T).
