Biology Chapter 5: Cells and Microscopy

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What is the main function of nucleoli within the nucleus?

To form ribosomes by assembling rRNA and proteins (correct)

To facilitate the transportation of proteins

To condense chromatin for cell division

To store genetic material as RNA and DNA

What happens to ribosomes formed in nucleoli?

They exit the nucleus and join on mRNAs in the cytoplasm (correct)

They are immediately degraded in the nucleus

They remain attached to the nuclear envelope permanently

They only function within the mitochondria

What characterizes eukaryotic chromosomes during cell division?

They consist of free-floating chromatin

They replicate fully before mitosis

They become condensed and coiled (correct)

They dissolve into the nuclear fluid

How are ribosomes categorized based on their location within the cell?

Free and attached ribosomes Signup and view all the answers

What does the structure of a eukaryotic ribosome consist of?

Two distinct subunits made of RNA and proteins Signup and view all the answers

What is a key advantage of using an electron microscope over a light microscope?

Shorter wavelength for higher resolution Signup and view all the answers

What is the primary function of Transmission Electron Microscopy (TEM)?

To pass electrons through a specimen to generate a cross-section Signup and view all the answers

Which materials are typically used to stain specimens for Scanning Electron Microscopy (SEM)?

Gold, palladium, or platinum Signup and view all the answers

What type of specimen preparation is required for both Transmission and Scanning Electron Microscopy?

Specimens should be chemically preserved, fixed, and dehydrated Signup and view all the answers

Which of the following statements accurately describes the ability of electron microscopes?

They can distinguish objects as small as 1nm. Signup and view all the answers

What is the main role of cells in living organisms?

Cells are the basic structural and functional unit. Signup and view all the answers

Which statement about unicellular and multicellular organisms is true?

Multicellular organisms develop specialized cells for different functions. Signup and view all the answers

Who contributed to the formulation of cell theory by observing plants?

Schleiden Signup and view all the answers

Why are most cells considered microscopic?

The size of cells relates to their functions, which are typically more efficient when small. Signup and view all the answers

Which of the following is NOT a basic feature of cell structure?

Store food in large quantities Signup and view all the answers

Who is credited with the observation that cells arise only from the division of preexisting cells?

Virchow Signup and view all the answers

Which biological processes are essential for life that cells must perform?

Use energy and respond to environmental changes Signup and view all the answers

What is a key difference between cells of unicellular and multicellular organisms?

Multicellular organisms have cells that perform specialized roles. Signup and view all the answers

What is the primary structural role of the cytoskeleton in eukaryotic cells?

Supports and moves cell structures Signup and view all the answers

Which component of the nuclear envelope is responsible for regulating transport between the nucleus and cytoplasm?

Nuclear pore complex Signup and view all the answers

What distinguishes a capsule from a slime layer in the context of glycocalyx?

Capsules are firmly attached to cells, while slime layers are loosely associated. Signup and view all the answers

Which of the following structures provides support to plant, fungi, and some protist cells?

Supportive cell wall Signup and view all the answers

What is the primary composition of chromatin found within the nucleus?

DNA and proteins Signup and view all the answers

What is a fundamental difference between light microscopy and electron microscopy?

Light microscopy can view live cells, whereas electron microscopy can only view dead cells. Signup and view all the answers

Which statement accurately describes the function of the plasma membrane?

It provides selective transport for certain molecules. Signup and view all the answers

What component is essential for maintaining cell shape in eukaryotic cells?

Cytoskeleton Signup and view all the answers

What distinguishes the resolution capabilities of electron microscopy compared to light microscopy?

Electron microscopy can resolve structures down to 0.001 µm. Signup and view all the answers

What is one characteristic of the cytosol within the cytoplasm?

It is an aqueous solution with various organic molecules. Signup and view all the answers

Which property is associated with the use of heavy metals in electron microscopy?

They improve image contrast. Signup and view all the answers

In what way do prokaryotic and eukaryotic cells differ regarding DNA organization?

Eukaryotic cells have DNA organized within a nucleus; prokaryotic cells do not. Signup and view all the answers

What is the primary role of transport protein channels in the plasma membrane?

To facilitate selective transport of substances. Signup and view all the answers

Which type of microscopy provides a greater magnification than 10,000x?

Electron Microscopy Signup and view all the answers

What is a common characteristic of all cells, regardless of type?

Surrounded by a plasma membrane. Signup and view all the answers