Cell Theory
Who were the three scientists that are attributed to the cell theory?
Schleiden, Schwann, Virchow
What organelle is known as the “powerhouse of the cell”?
Mitochondria
What part of the cell membrane helps it stay flexible and selectively permeable?
The phospholipid bilayer
What is the movement of molecules from high to low concentration called?
Diffusion
What type of cell has a nucleus — prokaryotic or eukaryotic?
Eukaryotic
What scientist first named “cells” after observing cork under a microscope?
Robert Hooke
What organelle is responsible for making proteins?
Ribosomes
What term describes the cell membrane’s ability to let some things in and keep others out?
Selective permeability (or semi-permeable)
What process uses energy to move substances against the concentration gradient?
Active transport
What organelle stores genetic material?
Nucleus
What are the three main parts of the cell theory?
1. All living things are made of cells.
2. Cells are the basic unit of structure and function in living things.
3. All cells come from preexisting cells.
What structure do plant cells have that animal cells do not?
Cell Wall and Chloroplasts
What is the main component of the cell membrane?
Phospholipids
What type of transport involves protein channels but does not require energy?
Facilitated diffusion
What organelle packages and ships materials around the cell?
Golgi apparatus (Golgi body)
What major improvement in technology made the development of the cell theory possible?
The invention and improvement of the microscope
What is the function of lysosomes?
To break down waste materials and old cell parts using digestive enzymes
What role do carbohydrates play in the cell membrane?
They act as identification markers for cell recognition and communication.
What process brings large particles into the cell using vesicles?
Endocytosis
What’s the difference between smooth and rough ER?
Rough ER has ribosomes and makes proteins; smooth ER lacks ribosomes and makes lipids and detoxifies substances.
Why was the development of the cell theory one of the most important advancements in biology?
It established that cells are the foundation of all living things, connecting all life forms and enabling study of structure and function at the cellular level.
Describe two differences between prokaryotic and eukaryotic cells.
Prokaryotes have no nucleus or membrane-bound organelles; eukaryotes have both.
Explain how the fluid mosaic model describes the structure of the cell membrane.
It shows the membrane as flexible (“fluid”) and made of many different molecules—lipids, proteins, and carbohydrates—like a “mosaic.”
Compare and contrast osmosis and diffusion.
Both move particles from high to low concentration; osmosis specifically refers to the movement of water through a selectively permeable membrane.
Predict what will happen to an animal cell placed in a hypertonic solution and explain why.
It will shrink (crenate) because water moves out of the cell toward the area of higher solute concentration.