Explanation

Heterocysts are specialized nitrogen-fixing cells found in some cyanobacteria (e.g., Anabaena).

They provide an anaerobic environment necessary for the enzyme nitrogenase to fix atmospheric nitrogen.

Explanation

Acetyl chloride (CH₃COCl) cannot be prepared directly from acetic acid due to the poor leaving ability of the –OH group.

It requires a chlorinating agent like PCl₅, PCl₃, or SOCl₂ for conversion.

Therefore, it cannot be prepared directly from acetic acid.

Explanation

Saturation occurs when all active sites of the enzyme molecules are fully occupied by the substrate.

At this point, adding more substrate doesn't increase the reaction rate, as the enzyme is working at its maximum capacity (Vmax).

Explanation

Tertiary structure refers to the 3D folding of a protein, stabilized by interactions like disulphide bonds, hydrogen bonds, and hydrophobic interactions.

Disulphide (S-S) linkages are covalent bonds formed between cysteine residues, specifically contributing to the protein's tertiary structure stability.

Explanation

Ethanol (C₂H₅OH) is oxidized to ethanoic acid (CH₃COOH) using oxidizing agents like acidified potassium dichromate (K₂Cr₂O₇).

This chemical reaction involves the gain of oxygen or loss of hydrogen, which defines oxidation.

Explanation

Prokaryotic ribosomes are 70S in total, made up of 50S (large subunit) and 30S (small subunit) when dissociated.

These subunits come together during protein synthesis.

They are smaller than the eukaryotic 80S ribosomes.

Explanation

The actual CO₂ acceptor in the Calvin cycle is ribulose-1,5-bisphosphate (RuBP), a phosphorylated form of ribulose.

RuBP combines with CO₂ in a reaction catalyzed by Rubisco, initiating the Calvin cycle.

Explanation

Thermistors are temperature-sensitive resistors whose resistance changes with temperature.

This change affects the electrical voltage in a circuit, allowing temperature measurement.

Explanation

In a Cathode Ray Oscilloscope (CRO), the brightness of the spot is controlled by the intensity of the electron beam.

This intensity is regulated by the voltage on the anodes, hence anodes control brightness.

Explanation

Centripetal force acts perpendicular to the direction of motion in circular motion.

Since work = force × displacement × cos(θ), and θ = 90°, the work done is zero.