Cytology & cells

What is the basic structural and functional unit of life?

The cell

What are the two major types of cells?

Prokaryotic and eukaryotic.

What is the main difference between prokaryotic and eukaryotic cells?

Eukaryotic cells have a nucleus and membrane-bound organelles; prokaryotic cells do not.

What do both prokaryotic and eukaryotic cells have in common?

Plasma membrane, cytoplasm, ribosomes, and genetic material (DNA/RNA)

What is the structure of the cell membrane?

A phospholipid bilayer with embedded proteins, cholesterol, and carbohydrates

What is the main function of the cell membrane?

It controls what enters and leaves the cell, acting as a selective barrier.

What is diffusion?

The movement of molecules from an area of high concentration to low concentration.

What is osmosis?

The diffusion of water across a semipermeable membrane from high to low water concentration.

What is active transport?

Movement of molecules from low to high concentration using energy (ATP)

What is facilitated diffusion?

Movement of molecules through protein channels or carriers without using energy.

What is the cytoskeleton?

A network of fibers that maintain cell shape, anchor organelles, and help with movement and transport.

What are the three main components of the cytoskeleton?

Microfilaments, intermediate filaments, and microtubules.

What protein are microfilaments made of?

Actin.

Where are microfilaments mainly located?

Near the cell membrane.

What is the function of microfilaments?

Support cell shape and aid in movement.

What is the function of intermediate filaments?

Provide mechanical strength and stability; found randomly throughout the cell.

What are microtubules and where do they originate?

Hollow tubes that help with intracellular transport and cell division; they branch out from the nucleus/centrosome

What is the nucleus?

The control center of the cell that contains DNA and directs all cell activities.

What is the nucleolus. 

Found inside the nucleus; it produces rRNA and assembles ribosomes.

What is the cytoplasm?

A gel-like substance that suspends organelles and is the site of many metabolic reactions.

What is the function of mitochondria?

Produce ATP, the main energy molecule of the cell; “powerhouse of the cell.”

What is the rough endoplasmic reticulum (RER)?

Has ribosomes on its surface; synthesizes and modifies proteins.

What is the smooth endoplasmic reticulum (SER)?

Lacks ribosomes; synthesizes lipids and detoxifies substances.

What does the Golgi apparatus do?

Modifies, sorts, and packages proteins and lipids for transport.

What are ribosomes?

Sites of protein synthesis where amino acids are linked together using mRNA instructions.

What do lysosomes do?

Contain digestive enzymes to break down waste, old organelles, and foreign materials.

What are peroxisomes?

Detoxify harmful substances and break down fatty acids using oxidative enzymes.

What do centrioles do?

Help organize microtubules during cell division to form the mitotic spindle.

What is the function of vacuoles?

Store nutrients and waste; help maintain pressure in plant cells.

What are chloroplasts and where are they found?

Organelles in plant cells that carry out photosynthesis. 

What is the cell wall and where is it found?

A rigid outer layer found in plant cells that provides structural support and protection.

What is cell potency?

The ability of a stem cell to differentiate into other cell types.

Which cells are totipotent?

Cells that can form all cell types, including extraembryonic tissues (e.g., zygote)

Which cells are pluripotent?

Cells that can form almost all cell types but not an entire organism (e.g., embryonic stem cells)

Which cells are multipotent?

Cells that can form a limited range of related cell types (e.g., bone marrow stem cells).