Prepare for NEET with Botany-specific practice questions. Covering all major Botany chapters, this is perfect for your NEET Biology needs.
The 'histone code' hypothesis proposes that specific combinations of histone modifications influence gene expression. If a researcher discovered a novel histone modification, which experimental approach would be LEAST informative for initially investigating its potential role in gene regulation?
Analyzing the genome-wide distribution of the modification using ChIP-seq.
Correlating the presence of the modification with gene expression levels.
Assessing the binding of specific regulatory proteins to the modified histone.
Determining the crystal structure of the modified histone.
Which of the following statements regarding the signal recognition particle (SRP) and its receptor is INCORRECT?
The SRP receptor is an integral membrane protein of the ER.
SRP binds to both the signal sequence and the ribosome, halting translation.
SRP guides the ribosome-mRNA complex to the ER membrane.
SRP binds to the nascent polypeptide chain only after it has completely emerged from the ribosome.
Certain integral membrane proteins facilitate the passage of water across the cell membrane. These proteins are known as aquaporins and are crucial for maintaining cellular water balance. Which of the following is NOT a characteristic of aquaporin-mediated water transport?
Passive transport of water
Saturable transport kinetics
Driven by osmotic gradients
High selectivity for water
Lipid rafts are specialized microdomains within the cell membrane. Which of the following statements about their composition and function is INCORRECT?
They are enriched in cholesterol and sphingolipids.
They are involved in signal transduction and membrane trafficking.
They exhibit reduced fluidity compared to the surrounding membrane.
They are primarily composed of unsaturated phospholipids and peripheral membrane proteins.
The fluidity of the cell membrane is influenced by several factors. Which of the following would DECREASE membrane fluidity?
Increased proportion of unsaturated fatty acids
Shorter fatty acid chain length
Increased cholesterol content at high temperatures
Decreased cholesterol content at low temperatures
Two identical plant cells are placed in separate solutions. Cell A is placed in a 1M sucrose solution, and Cell B is placed in a 1M NaCl solution. Which cell will experience greater plasmolysis, assuming ideal conditions and complete dissociation of NaCl?
Cell A
Cell B
Both cells will plasmolyze equally
Neither cell will plasmolyze
A plant cell is placed in a solution, and its volume initially increases. After a while, the volume increase stops. Which of the following BEST explains why the volume stopped increasing?
The cell membrane reached its maximum stretching capacity.
All available water in the solution was absorbed by the cell.
The cell wall became impermeable to water.
Turgor pressure reached equilibrium with the external solution's osmotic pressure.
Certain integral membrane proteins facilitate the diffusion of molecules across the membrane without directly binding to the transported molecule. These proteins create a continuous aqueous pathway through the lipid bilayer. Which of the following is the BEST example of such facilitated diffusion?
GLUT transporters moving glucose
Sodium-potassium pump maintaining ion gradients
Aquaporins transporting water
Chloride channels gated by voltage
Which of the following statements regarding facilitated diffusion is INCORRECT?
It requires transport proteins.
It is a passive process and does not require energy.
It can move molecules against their concentration gradient.
Transport proteins involved can become saturated.
Imagine a plant cell undergoing plasmolysis. If the external solution's water potential is further decreased, which of the following is the MOST likely consequence?
Deplasmolysis and return to a turgid state.
Incipient plasmolysis with the cell membrane just touching the cell wall.
No further change in the cell's state.
Increased plasmolysis with further shrinkage of the protoplast.
