A2.2 Cell Structure

What is the basic structural unit of all living organisms?

Cells are the basic structural unit of all living organisms.

What is magnification in microscopy?

Magnification = measured length / actual length

What is resolution in microscopy?

Resolution is the ability of a microscope to distinguish the details of a specimen or sample.

What does cryogenic electron microscopy allow scientists to do?

View proteins and other biomolecules that do not readily crystallize.

What is freeze-fracture electron microscopy used for?

Examining the ultrastructure of rapidly frozen biological samples.

What are fluorescent stains used for in light microscopy?

Visualizing specific proteins or antigens in cells or tissues.

What is homeostasis in unicellular organisms?

The maintenance of internal conditions within a narrow range.

What is metabolism?

The complex network of interdependent and interacting chemical reactions occurring in living organisms.

What is the function of ribosomes?

Protein synthesis.

What do eukaryotic cells have that prokaryotic cells do not?

A nucleus and membrane-bound organelles.

What is the main component of the plasma membrane?

A phospholipid bilayer.

What is turgor pressure?

The force within the cell that pushes the plasma membrane against the cell wall.

What are meristematic tissues in plants?

Tissues containing undifferentiated cells capable of differentiating into specialized cells.

What does the endosymbiotic theory propose?

That eukaryotes evolved from a common unicellular ancestor through a process involving engulfment of prokaryotic cells.

What type of cells do not have a nucleus?

Red blood cells and phloem sieve tube elements.

What is the role of mitochondria?

Produce ATP by aerobic respiration.

What is the significance of the Golgi apparatus?

Modifies proteins received from the rough endoplasmic reticulum and packages them for secretion.

What are the characteristics of chloroplasts?

Contain chlorophyll and carry out photosynthesis.

What is the key difference between prokaryotic and eukaryotic chromosomes?

Prokaryotic chromosomes are not associated with proteins and are found in the nucleoid region.

What is a key feature of eukaryotic cells?

They have multiple membrane-bound organelles.

What is one advantage of being multicellular?

Specialized tissues allow for more efficient use of resources.

What do stem cells differentiate into?

Specialized cells with specific functions.

What do ribosomes look like in micrographs?

They appear as spherical dots with a dark center.

What is the function of the rough endoplasmic reticulum?

Site for protein synthesis.

Why is the plasma membrane important for a cell?

Controls what enters and exits the cell.

What structure surrounds the prokaryotic cell?

The peptidoglycan cell wall.

What is the sap vacuole's main function in plants?

Stores nutrients and wastes, and maintains turgor pressure.

What is excretion in the context of unicellular organisms?

The removal of metabolic waste.

What do different colored fluorescent stains allow scientists to do?

Label different molecules to study interactions between them.

What are integral proteins?

Proteins that span the phospholipid bilayer in cell membranes.

What is a characteristic shared by both prokaryotic and eukaryotic cells?

Both have a plasma membrane.

What is the function of smooth endoplasmic reticulum?

Production of lipids and detoxification of harmful substances.

How are chloroplasts and mitochondria similar to prokaryotic cells?

They reproduce through binary fission and have a similar size.

What type of microscopy helps visualize dynamic processes in living tissue?

Immunofluorescence.

What do eukaryotic cells utilize for energy production?

Mitochondria.

What is one role of the nucleus in a eukaryotic cell?

Contains the chromosomes and genetic information.

What do microvilli do in animal cells?

Increase the surface area for transport of materials.