CYTOLOGY and Cell Structure

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Which region of nucleolonema contains dense granules representing maturing ribosomal subunits during assembly for export to the cytoplasm?

Nucleoplasm

Pars granulosa (correct)

Nucleus matrix

Pars fibrosa

What characterizes Pars fibrosa of nucleolonema?

Dense granules

Composed of enzymatic and non-enzymatic proteins

Contains filamentous intracellular material

Consists of densely packed ribonucleic protein fibers (correct)

Which structure surrounds epithelial cells in a belt-like fashion?

Belt desmosomes or zonula adherens (correct)

Nucleolonema

Spot desmosomes or macula adherens

Pars granulosa

What is the main composition of the nucleoplasm?

Enzymatic and non-enzymatic proteins, metabolites, ions, and water Signup and view all the answers

What is the size range of spot desmosomes or macula adherens?

~200-400 nm in diameter Signup and view all the answers

What appears second in the Pars fibrosa region of nucleolonema?

Newly synthesized rRNA Signup and view all the answers

What does the mitochondrial matrix contain?

Water, solutes, and large matrix granules Signup and view all the answers

Which process is mainly associated with the Krebs cycle in the mitochondria?

Yielding CO2 and NADH along the respiratory chain Signup and view all the answers

What is a key function of mitochondria related to energy production?

Generating ATP by storing energy from cellular metabolites Signup and view all the answers

Which statement accurately describes mitochondrial DNA (mtDNA)?

It is replicated independently of the cell cycle Signup and view all the answers

How do mitochondria reproduce themselves?

Using fission or budding processes Signup and view all the answers

Where are mitochondria typically located within cells?

Randomly distributed throughout the cytoplasm Signup and view all the answers

Which of the following is NOT a function of the rough endoplasmic reticulum (rER)?

Synthesis of complex lipids Signup and view all the answers

Which of the following statements about the smooth endoplasmic reticulum (sER) is INCORRECT?

It is responsible for the synthesis of secretory proteins. Signup and view all the answers

What is the primary function of the Golgi complex?

Coordinating membrane flow and vesicle traffic among organelles Signup and view all the answers

Which of the following is a function of the smooth endoplasmic reticulum (sER) in hepatocytes (liver cells)?

Synthesis of complex lipids and drug detoxification Signup and view all the answers

Which organelle is responsible for the release and capture of $Ca^{2+}$ ions in striated muscle cells?

Smooth endoplasmic reticulum (sER) Signup and view all the answers

Which of the following statements about the Golgi complex is INCORRECT?

It is involved in the synthesis of secretory proteins. Signup and view all the answers

Which of the following statements about cells is correct?

Cells are the structural and functional units of all living organisms. Signup and view all the answers

What is the primary difference between prokaryotic and eukaryotic cells?

Eukaryotic cells have a nuclear envelope and membrane-bound organelles, while prokaryotic cells lack these structures. Signup and view all the answers

Which of the following factors does NOT influence the shape of a cell?

The presence or absence of a cell wall Signup and view all the answers

Which of the following statements about cellular size is correct?

Cellular size can vary widely, even among cells of the same type. Signup and view all the answers

Which of the following is NOT a characteristic of eukaryotic cells?

They lack a nuclear envelope and histones. Signup and view all the answers

What is the primary function of the cell membrane?

To regulate the exchange of materials between the cell and its environment Signup and view all the answers

Which of the following statements about intermediate filaments is correct?

They play a role in maintaining cell shape and epithelial cell adhesion. Signup and view all the answers

Which of the following is NOT a type of intermediate filament mentioned in the text?

Actin filaments Signup and view all the answers

What is the primary function of microtubules?

Transporting molecules within the cell Signup and view all the answers

What are the subunits that make up the walls of microtubules called?

Tubulin heterodimers Signup and view all the answers

How many protofilaments align parallel to one another to form the wall of a microtubule?

13 Signup and view all the answers