Prepare for NEET with Botany-specific practice questions. Covering all major Botany chapters, this is perfect for your NEET Biology needs.
Prions, infectious protein particles, can induce conformational changes in normal proteins, leading to diseases like Creutzfeldt-Jakob disease. While exhibiting self-propagation, prions lack genetic material. Do prions challenge the conventional definition of living organisms, and why?
No, because they are composed of organic molecules.
Yes, because they lack heritable genetic material yet exhibit a form of 'reproduction'.
No, because they interact with living organisms.
Yes, because they cause disease.
Imagine a synthetic life form created in a lab that uses a novel information storage molecule distinct from DNA or RNA, but still exhibits heritability and undergoes evolution. Which of the following aspects of the current definition of life would MOST require reconsideration in light of this discovery?
The requirement for cellular structure
The dependence on carbon-based chemistry
The specific molecular basis of heredity
The ability to respond to environmental stimuli
Consider a plant with a compound umbel inflorescence. If each ray of the main umbel bears a small, condensed cyme instead of a single flower, how would this modified inflorescence be BEST classified, and what advantage might this structure confer?
Cyme of umbels; enhanced seed dispersal
Compound raceme of umbels; protection from herbivores
Compound umbel of cymes; increased flower number and display area
Hypanthodium; trap for pollinators
A mutant plant exhibits stunted root growth and reduced gravitropic response. Microscopic analysis reveals disorganized columella cells in the root cap. Which of the following is the MOST likely cause of this phenotype?
Increased production of cytokinin in the root tip
Disruption of amyloplast sedimentation and auxin redistribution
Overexpression of genes involved in cell elongation
Enhanced sensitivity to ethylene
A researcher is studying the transport of a novel molecule across a synthetic lipid bilayer. They observe that the molecule moves down its concentration gradient without the need for any membrane proteins or energy input. However, the rate of transport is significantly slower than predicted for simple diffusion. Which of the following BEST explains this observation?
The molecule is very large and its size restricts diffusion through the membrane.
The molecule is charged and is repelled by the hydrophobic core of the bilayer.
The molecule is polar and its passage is hindered by the hydrophobic core of the bilayer.
The molecule is binding to a specific receptor on the membrane surface, slowing its diffusion.
A plant cell with a water potential of -0.65 MPa is placed in a solution with a water potential of -0.30 MPa. Assuming the cell wall is rigid and fully permeable, and the cell membrane is selectively permeable, what will be the pressure potential of the cell at equilibrium?
-0.95 MPa
-0.35 MPa
+0.35 MPa
+0.95 MPa
Imagine a U-shaped tube with a selectively permeable membrane separating two solutions. Side A contains a 0.2M sucrose solution, and Side B contains a 0.1M NaCl solution. Initially, the levels are equal. Considering the dissociation of NaCl and the non-penetrating nature of sucrose and NaCl, which side will have a higher level at equilibrium?
Side A
Side B
The levels will remain equal
The membrane will rupture
A researcher observes that a particular plant cell placed in a solution exhibits incipient plasmolysis. If the solute potential of the cell is -1.2 MPa, what is the MOST likely water potential of the surrounding solution?
-1.2 MPa
-1.0 MPa
-1.4 MPa
-0.8 MPa
A plant cell is placed in a solution with a water potential of -0.8 MPa. The cell's initial solute potential is -1.2 MPa and its pressure potential is 0.4 MPa. After equilibration, which of the following statements about the cell's state is MOST accurate?
The cell will be turgid, with a pressure potential greater than 0.4 MPa.
The cell will be flaccid, with a pressure potential of zero.
The cell will be plasmolyzed, with a pressure potential of zero.
The cell will experience incipient plasmolysis, with a pressure potential slightly above zero.
A researcher observes that water absorption by roots is significantly reduced when the plant is treated with a respiratory inhibitor. Which of the following best explains this observation?
Respiratory inhibitors directly block aquaporin function, preventing water movement.
Respiration is essential for maintaining root cell turgidity, which is directly linked to water absorption.
Active transport of ions into the root cells requires energy, creating a water potential gradient that drives water uptake.
Inhibition of respiration disrupts the cohesion-tension theory, preventing water movement through the xylem.
