Nucleus and its components

• If a cell needs to produce a large amount of a specific protein, which type of chromatin would be more prevalent?

  Euchromatin
• What is the role of DNA in the nucleus?

  Contains genetic instructions
• What is chromatin in the nucleus?

  Scattered threads
• How does the structure of the nucleus differ from the structure of the cytoplasm?

  The nucleus contains the genetic material, while the cytoplasm contains the organelles and other cellular components
• What are the five key components of the nucleus?

  Nuclear pores, chromatin, nucleolus, nucleoplasm, nuclear envelope
• How does DNA form chromatin?

  DNA wraps around protein complexes called nucleosomes
• How does the nucleus function like a boss in a toy factory?

  It makes decisions and provides instructions
• What is the function of the nucleus?

  Directs all cell activities
• What is the name of the dense, central region within the nucleus?

  Nucleolus
• What is the purpose of the nuclear envelope?

  It keeps everything safe inside the nucleus
• What is the name of the semi-fluid, gel-like substance within the nuclear envelope?

  Nucleoplasm
• What is the function of the nuclear envelope in the cell?

  It separates the nucleus from the cytoplasm
• What is the name of the semi-fluid, gel-like substance within the nuclear envelope?

  Nucleoplasm
• How does the structure of chromatin differ from the condensed chromosome structure?

  • Chromatin is the less condensed form of DNA and histones
  • Condensed chromosome structure is the highly compacted form during cell division
  • Chromatin has a "beads on a string" appearance, while condensed chromosomes have a distinct X-shaped structure
• What is the structure of the nuclear envelope?

  Double membrane
• What is the name of the strand that is continuously synthesized during DNA replication?

  Leading strand
• What is the nucleus of a cell often referred to as?

  Control center
• What is the nucleolus?

  A dense region within the nucleus
• How does the leading strand differ from the lagging strand during replication?

  The leading strand synthesizes continuously
• What does rRNA stand for?

  Ribosomal RNA
• What is the role of DNA ligase in DNA replication?

  Joins Okazaki fragments together
• How can the nucleus be compared to a company's management?

  • The nucleus is like the president's office
  • Manages all operations of the cell
  • Directs activities similar to management roles
• What is the name of the outermost layer of the nucleus?

  Nuclear envelope
• How do the functions of euchromatin and heterochromatin differ?

  Euchromatin is active and transcribed, while heterochromatin is inactive and condensed
• What are the steps in the formation of chromatin?

  1. DNA helix wraps around histone proteins
  2. Multiple nucleosomes form solenoid fiber
  3. Fiber coils into tight chromosomes during cell division
• If a cell needs to transport a large molecule through the nuclear envelope, which structure would it use?

  Nuclear pore
• How do the leading and lagging strands differ in DNA replication?

  • Leading strand: Continuous DNA synthesis in 5' to 3' direction
  • Lagging strand: Discontinuous DNA synthesis in 5' to 3' direction, forming Okazaki fragments
• How does the nuclear envelope protect DNA?

  It isolates DNA from cytoplasm interference
• What is the function of DNA polymerase?

  Builds new complementary strands
• What are the two main types of chromatin?

  • Euchromatin: Less condensed, active chromatin
  • Heterochromatin: More condensed, inactive chromatin
• If a cell needs to produce a large amount of a specific protein, which type of chromatin would be more prevalent?

  Euchromatin
• What are the small, dense bodies within the nucleoplasm?

  • Ribosomes
• What is the starting point of DNA replication?

  Origin of replication
• If the radius of the solenoid chromatin fiber is $r =$$5\text{ nm}$, what is the circumference of the fiber?


  $10\pi \text{ nm}$
• What is chromatin?

  Uncondensed DNA that forms with proteins
• What is the function of the nuclear envelope?

  • Separates the nucleus from the cytoplasm
  • Regulates the movement of materials in and out of the nucleus
• Why is the condensation of chromosomes important during mitosis?

  It ensures even distribution of DNA
• What is the function of the nucleus?

  It makes important decisions for the cell
• What is the name of the dense, central region within the nucleus?

  Nucleolus
• What is the name of the DNA fragment synthesized on the lagging strand during replication?

  Okazaki fragment