Prepare for NEET with Botany-specific practice questions. Covering all major Botany chapters, this is perfect for your NEET Biology needs.
Which unique feature of prokaryotic DNA replication allows for rapid cell division?
Presence of introns
Single origin of replication
Linear chromosomes
Multiple replication forks
Certain histone modifications are associated with actively transcribed genes. Which of the following combinations is MOST likely to be found in the nucleosomes of such genes?
Methylation of H3K9 and H3K27; Deacetylation of H3 and H4
Phosphorylation of H2AX; Trimethylation of H3K9
Acetylation of H3 and H4; Trimethylation of H3K4
Ubiquitination of H2A; Trimethylation of H3K27
Polytene chromosomes, found in certain insect tissues, exhibit distinct banding patterns. These bands represent:
Individual genes arranged linearly along the chromosome.
Regions of heterochromatin exclusively.
Regions where DNA replication has been halted prematurely.
Regions of highly condensed chromatin corresponding to inactive genes interspersed with less condensed regions of active genes.
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 these processes is directly influenced by the level of chromatin compaction?
DNA replication
RNA processing
Gene expression
Protein translation
A transgenic mouse expressing a human growth hormone gene exhibits gigantism. Researchers discover a second transgenic mouse line with the same human growth hormone gene construct, yet these mice show normal growth. Which of the following is the MOST LIKELY explanation for this discrepancy?
The second mouse line has a mutation in the mouse growth hormone receptor gene.
The human growth hormone gene is not being transcribed in the second mouse line.
Position effect variegation due to the transgene's insertion site in the second mouse line.
The second mouse line expresses an endogenous inhibitor of human growth hormone.
A transgenic animal is created by inserting a gene for enhanced muscle growth into its genome. However, the resulting offspring show a variety of phenotypes, some with significantly enhanced muscle growth, others with moderate enhancement, and some with no change at all. Which phenomenon is MOST likely responsible for this phenotypic variation?
Incomplete penetrance of the transgene
Pleiotropic effects of the transgene
Variable transgene copy number and integration sites
Epigenetic silencing of the transgene in some individuals
Which of the following techniques is NOT typically used in pharmacogenomics to identify genetic variations influencing drug response?
Single nucleotide polymorphism (SNP) analysis
Genome-wide association studies (GWAS)
Gene expression profiling
Satellite DNA profiling
The introduction of a foreign gene into an animal's genome can result in:
Overexpression of the introduced gene
Silencing of the introduced gene
Position effects influencing gene expression
All of the above
A primary challenge in gene therapy is ensuring the therapeutic gene is expressed:
(a) Continuously
(b) Only in target cells
(c) At the correct level
(d) All of the above
(a) Continuously
(b) Only in target cells
(c) At the correct level
(d) All of the above
