THE NUCLEUS
What is the function of the nucleus?
The nucleus maintains the integrity of genes and controls cell activities by regulating gene expression.
What is DNA composed of?
DNA is composed of nucleotides, which include a sugar, a phosphate group, and a nitrogenous base.
What are the components of the nuclear envelope?
The nuclear envelope consists of two lipid bilayers, an inner membrane, and an outer membrane.
What is the primary function of the nucleolus?
The primary function of the nucleolus is the assembly of ribosomes.
What is contained within the nucleus?
The nucleus contains the cell's genetic information, encoded in DNA.
How is DNA organized in eukaryotic cells?
DNA is organized into long strands that coil around proteins to form chromosomes within the nucleus.
What role do nuclear pores play?
Nuclear pores regulate the exchange of materials, such as RNA and proteins, between the nucleus and the cytoplasm.
What is ribosomal RNA (rRNA)?
Ribosomal RNA (rRNA) is a type of RNA that, along with proteins, makes up ribosomes.
How does the nucleus regulate gene expression?
The nucleus regulates gene expression by controlling which genes are "turned on" or "off" in response to cellular needs.
What are chromosomes and their function?
Chromosomes are structures made of coiled DNA and proteins that contain many genes and are responsible for the genetic information of the cell.
Explain the relationship between the nuclear envelope and the endoplasmic reticulum.
The outer membrane of the nuclear envelope is continuous with the rough endoplasmic reticulum, facilitating communication.
How are ribosomes assembled in the nucleolus?
Ribosomes are assembled in the nucleolus by combining rRNA with proteins.
What is the structure of the nuclear envelope?
The nuclear envelope is a double membrane composed of an inner and outer lipid bilayer.
What is the role of genes in DNA?
Genes are segments of DNA that encode information necessary for synthesizing proteins and regulating cellular functions.
How does the nuclear envelope protect DNA?
The nuclear envelope isolates the genetic material from the cytoplasm, protecting it from potential damage.
Where do ribosomes go after being made?
After being made in the nucleolus, ribosomes are exported to the cytoplasm to direct protein synthesis.
Describe the significance of chromatin.
Chromatin is a loosely coiled form of DNA that allows for gene expression and DNA replication during the cell cycle.
How does DNA coiling affect chromosome structure?
The degree of DNA coiling determines whether chromosomes are short and thick or long and thin, impacting their visibility and function during cell division.
Why is the nuclear envelope important?
The nuclear envelope is crucial for maintaining the environment of the nucleus and regulating what enters and exits.
Describe the importance of ribosomes in the cell.
Ribosomes are essential for translating mRNA into proteins, which are crucial for cellular function and structure.