Prepare for NEET Biology Cell: The Unit of Life with MCQs & PYQs on NEET.GUIDE. Enjoy free practice, previous year questions, and expert solutions to understand cell structure and function.
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
Balbiani rings are prominent structures found in:
Polytene chromosomes
Lampbrush chromosomes
Meiotic chromosomes
Mitotic chromosomes
Which of the following is associated with the synthesis of secretory proteins?
Balbiani rings
Nucleolus
Centromere
Telomere
The large puffs on polytene chromosomes, known as Balbiani rings, are primarily involved in:
RNA synthesis
DNA replication
Protein degradation
Chromosome condensation
If Balbiani rings are disrupted, which cellular process is most likely to be directly affected?
Production of secretory proteins
DNA replication
Ribosomal RNA synthesis
Cellular respiration
The DNA present in chloroplasts is responsible for:
Encoding all cellular proteins
Controlling cell division
Regulating nuclear gene expression
Encoding some chloroplast proteins
