NEET Biology: Nucleus structure Practice Questions
15 free multiple-choice questions on Nucleus structure (Cell Structure and Function) for NEET Biology, each with the correct answer and a step-by-step explanation. Attempt a question, then reveal the solution to check your reasoning.
Practice thousands more NEET questions in the app →Q1. Which component provides structural support and defines the shape of the nuclear envelope?
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Correct answer: B — Nuclear lamina
The nuclear lamina, a network of intermediate filaments underlying the inner nuclear membrane, provides structural support to the nuclear envelope.
Q2. The nuclear envelope is fundamentally delimited by which structure?
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Correct answer: A — Nuclear Membrane
The nuclear envelope is a double membrane structure. The inner boundary is defined by the nuclear lamina, and the outer boundary forms the nuclear membrane.
Q3. The genetic material (DNA) within the nucleus is primarily organized in which form during interphase?
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Correct answer: C — Chromatin
During interphase, DNA is tightly coiled around histone proteins to form chromatin, which condenses into chromosomes during cell division.
Q4. The nuclear envelope is a double membrane structure. What is the primary function of the nuclear envelope?
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Correct answer: C — Transport of materials between nucleus and cytoplasm
The nuclear envelope regulates the passage of macromolecules, including proteins and RNA, between the nucleus and the cytoplasm, maintaining the compartmentalization of genetic material.
Q5. The material found inside the nucleus, surrounding the chromosomes, is primarily composed of which type of macromolecular structure?
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Correct answer: A — Chromatin
The bulk material inside the nucleus, where DNA is organized, is primarily chromatin (DNA complexed with proteins).
Q6. The material that constitutes the genetic material in the form of long, linear chains of DNA and associated proteins within the nucleus is known as:
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Correct answer: A — Chromatin
Chromatin is the complex of DNA and proteins (primarily histones) that makes up eukaryotic chromosomes.
Q7. The nuclear pore complexes (NPCs) act as channels connecting the nucleus to the cytoplasm. What is the main role of these pores?
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Correct answer: D — Regulating the transport of molecules
Nuclear pore complexes are essential for regulating the bidirectional transport of molecules (like RNA and proteins) between the nucleoplasm and the cytoplasm.
Q8. What is the dense, dark-staining structure typically found within the nucleus, responsible for ribosome synthesis?
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Correct answer: A — Nucleolus
The nucleolus is a dense structure within the nucleus where ribosomal RNA (rRNA) is synthesized and ribosome subunits are assembled.
Q9. Which structure is responsible for regulating the passage of molecules between the nucleus and the cytoplasm?
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Correct answer: B — Nuclear pores
Nuclear pores are protein complexes embedded in the nuclear envelope that regulate the transport of macromolecules (like RNA and proteins) into and out of the nucleus.
Q10. Which of the following structures is directly associated with the distribution of genetic material within the nucleus?
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Correct answer: C — Chromatin
Chromatin represents the complex of DNA and proteins that makes up the genetic material, which is organized within the nucleoplasm.
Q11. The viscous, semi-fluid material that fills the space inside the nuclear envelope is known as:
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Correct answer: A — Nucleoplasm
Nucleoplasm is the viscous material that fills the interior space of the nuclear envelope, containing the chromatin and nucleoids.
Q12. The thread-like structures made of DNA and proteins that make up the genetic material within the nucleus are called:
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Correct answer: B — Chromatin
Chromatin refers to the complex of DNA and proteins (histones) that makes up the thread-like structure of genetic material inside the nucleus.
Q13. The primary functional role of the nucleoplasm is to serve as the medium for which of the following occurs?
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Correct answer: C — Movement of nuclear material
The nucleoplasm is the aqueous, fluid-filled space within the nucleus where most biochemical reactions and molecular processes take place.
Q14. Which structure within the nucleus is primarily responsible for the synthesis of ribosomal RNA (rRNA)?
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Correct answer: B — Nucleolus
The nucleolus is the dense, non-membrane-bound structure within the nucleus responsible for ribosome subunit synthesis, which requires rRNA transcription and ribosome assembly.
Q15. The nuclear envelope is selectively permeable, which means it controls the movement of substances. This selective permeability is primarily mediated by:
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Correct answer: D — Nuclear pores
The nuclear pores allow specific macromolecules (like RNA and proteins) to pass through the membrane, mediating transport into and out of the nucleus.
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