Bio Ch. 4

The architecture of cell surfaces can be viewed in the most detail using a _______.

scanning electron microscope

The term resolving power refers to _______.

the clarity of the image in showing two objects as separate

A normal size range for a typical eukaryotic cell is ________.

10 to 100 micrometers

The maximum size of a cell is limited by ________.

its need for enough surface area to make exchanges with its environment

What are the limits on which maximum cell size depends?

surface-to-volume ratio

To enter or leave any cell, substances must pass through ________.

the plasma membrane

Phospholipid bilayer membranes are semipermeable. Which of the following can move across the membrane without assistance?

O₂

Which of the following structures is/are found in prokaryotic cells?

ribosomes

Bacterial cells are prokaryotic; unlike a typical eukaryotic cell, they _______.

lack a nucleus

A certain cell has a dense nucleoid region, ribosomes, but no membrane-enclosed organelles. Based on this information, it could be ________.

an archaean

Which of the following are found in prokaryotic cells?

ribosomes

Which of the following would be found in the cytoplasm of a eukaryotic cell?

centrioles

The nucleolus _________.

manufactures ribosomes

Most of the DNA in a eukaryotic cell is in the _________.

nucleus

A plant cell was grown in a test tube containing radioactive nucleotides, the monomers from which DNA is built. Later examination of the cell showed the radioactivity to be concentrated in the _________.

nucleus

Under a light microscope, which substance becomes visible as the cell divides?

chromatin

Where are the ribosomes that produce enzymes responsible for the first steps of sugar metabolism found?

cytoplasm

Which of these is a function of the endomembrane system?

molecule export

Digestive cells produce many enzymes that break down ingested food. These cells have a large number of ribosomes ________.

on the rough endoplasmic reticulum

Of the following organelles, which group is involved in manufacturing the substances needed by the cell?

ribosomes, rough endoplasmic reticulum, smooth endoplasmic reticulum

The rough endoplasmic reticulum is considered to be in which general functional category of organelle?

manufacturing

Pancreatic cells secrete lots of proteins. With this in mind, which of the following organelles would be especially abundant in pancreatic cells?

rough endoplasmic reticulum

In muscle cells, the _______ is/are specialized for the storage and release of calcium.

smooth endoplasmic reticulum

Membrane proteins are synthesized by ribosomes that are attached to ________.

the endoplasmic reticulum

When isolated liver cells are combined with toxins, initial processing in the _______ increases the solubility of those compounds as an initial step in their excretion.

smooth endoplasmic reticulum

You would expect a cell with an extensive Golgi apparatus to _____.

secrete a lot of material

A researcher made an interesting observation about a protein made by the rough endoplasmic reticulum and eventually used to build a cell’s plasma membrane. The protein in the membrane was actually slightly different from the protein made in the ER. The protein was probably altered in the _____.

Golgi apparatus

Lysosomes are derived from _____ and function in _____.

the Golgi apparatus and rough endoplasmic reticulum …digestion of worn-out organelles

Which of the following is the most likely consequence for a cell lacking
functional lysosomes?

The cell becomes crowded with undigested wastes.

The contractile vacuole _____.

eliminates excess water from the cytoplasm of freshwater protists

Peroxisomes are organelles that are involved in the _____.

breakdown of fatty acids

What are the inner folds of the mitochondria called?

cristae

The purpose of cellular respiration is the production of _____.

ATP

Mitochondria appear in the greatest numbers in cells that are _____.

metabolically active

Chloroplasts are found in _____.

plant cells and some protists

Which cellular organelle is required for photosynthesis to occur in eukaryotic cells?

chloroplast

Mitochondria and chloroplasts are similar in that they both _____; they are different in that chloroplasts, but not mitochondria, _____.

have a double membrane … carry out photosynthesis

The internal skeleton of a cell is composed of _____.

microtubules, intermediate filaments, and microfilaments

When elongated, tube-shaped cells from the lining of the intestine are treated with a certain chemical, the cells sag and become rounded. The internal structures disrupted by this chemical are probably _____.

microtubules

Where would you expect to find contractile proteins in a cell?

cytoskeleton

The protein actin is a component of a(n) _____.

microfilament

Cilia and flagella move due to energy provided by the enzymatic breakdown of ATP by _____.

dynein arms

Basal bodies are most closely associated with which of the following cell components?

cilia

Primary ciliary dyskinesia is a genetic disorder in which the cilia of the respiratory tract become immobile. As a result, these individuals suffer respiratory illnesses. This is because the cells _____.

lack dynein arms

Integrins are proteins that are responsible for integrating changes that are occurring outside and inside the cell. They are able to do this because of _____.

microfilaments

Your intestine is lined with individual cells. No fluids leak between these cells from the gut into your body. Why?

The intestinal cells are bound together by tight junctions.

Which of the following structures is directly involved in the passage of electrical signals between cells as, for example, in the vertebrate heart?

gap junctions

Dye injected into a plant cell might be able to enter an adjacent cell through a(n) _____.

plasmodesma

The cell junctions in plant cells that provide channels between adjacent cells are generally _____.

plasmodesmata

The general function of _____ is the breakdown of substances.

peroxisomes