Prepare for NEET with Botany-specific practice questions. Covering all major Botany chapters, this is perfect for your NEET Biology needs.
Imagine a scenario where a novel amino acid is discovered. If the existing genetic code must accommodate this new amino acid without altering the existing amino acid assignments, what is the MOST likely mechanism for achieving this?
Expansion of the codon length from three to four bases
Overlapping reading frames
Reassignment of a rarely used codon
Modification of the ribosome structure
During translation, a tRNA molecule carrying a specific amino acid recognizes the corresponding codon on the mRNA through its anticodon. A mutation occurs in the anticodon loop of a tRNA specific for alanine, changing it from 3'-CGI-5' to 3'-CCI-5'. Assuming the wobble hypothesis applies, what is the MOST LIKELY consequence of this mutation?
The tRNA will no longer recognize any codons.
The tRNA will insert glycine into the polypeptide chain instead of alanine.
The tRNA will still carry alanine but will recognize different alanine codons.
The mutation will have no effect on protein synthesis.
A researcher is studying translation in a prokaryotic cell. They introduce a modified mRNA where all the guanine nucleotides in the coding sequence are replaced with inosine. Which of the following is the MOST LIKELY effect on translation?
Translation will terminate prematurely due to the presence of inosine.
The ribosome will be unable to bind to the modified mRNA.
The protein synthesized will be identical to the one produced from the unmodified mRNA.
The protein synthesized will have altered amino acid sequence due to changes in codon recognition.
Imagine a scenario where glucose is absent, but a non-hydrolyzable analog of lactose is present in the medium. This analog can bind to the repressor but cannot be metabolized. Predict the level of lac operon expression compared to a wild-type strain in the presence of lactose and absence of glucose.
No expression
Basal level of expression
Similar level of expression
Significantly lower expression
A child's DNA fingerprint shows a band that is not present in either parent's profile. What is the MOST likely explanation for this observation, assuming no technical errors?
Sample contamination
Technical error during PCR
Mutation in a germ cell of one parent
Incomplete digestion by restriction enzymes
The uptake of potassium (K+) by plant roots can be described by the Michaelis-Menten kinetics. If the maximum uptake rate (Vmax) for K+ is reached at a relatively low external K+ concentration, what can be inferred about the affinity of the K+ transporter?
The K+ transporter has a low affinity for K+.
The K+ transporter is non-specific for K+.
The K+ transporter is inhibited by high K+ concentrations.
The K+ transporter has a high affinity for K+.
A sample of detritus undergoes decomposition under controlled conditions. Initially, the C:N ratio is 40:1. After a significant period, the fungal biomass significantly increases. What is the MOST LIKELY change in the C:N ratio of the remaining detritus?
Increases
Decreases
Remains the same
Fluctuates unpredictably
Given below are two statements:
Statement I: The primary acceptor in plants is phosphoenolpyruvate and is found in the mesophyll cells.
Statement II: Mesophyll cells of plants lack RuBisCo enzyme
In the light of the above statements, choose the correct answer from the options given below:
Both Statement I and Statement II are true and Statement II is the correct explanation of Statement I
Both Statement I and Statement II are true but Statement II is not the correct explanation of Statement I
Statement I is true but Statement II is false
Statement I is false but Statement II is true
