Biology 100 Unit 4 Flashcards
In 1665 Robert Hook found
cells
Cells are small functional units that are characterized by ___________. Living organisms are made from ____________
Living, One or more cells
Why are cells small?
So that molecules may enter and leave fast enough to meet the cells needs
How does a light microscope work?
- Light passes through the speciman
- A set of optical lenses enlarge it
_____ organisms are composed of cells
all
What is cell theory?
- all organisms are composed of cells
- all cells are composed of previously existing cells
Electron microscopes use_____________ allowing us to see up to ________ times which allows us to view ___________
a focused beam of electrons, 100,00x, intercellular structures and even viruses
A ___________ is used to look at the surface of a small object. The electron beam is reflected off of the object’s ____________________
scanning electron microscope, surface irregularities
_______________ is useful for explore the internal structure. The electron beam passes through the object and some structures slow the electrons
The transmition microscope
What are the two major types of cells
- prokryotic
- eukaryotic
who are unicellular
bacteria and protist
who are multicellular
plants and animals
What make prokaryotic cells unique
- very small
- no nucleus
- No organelles
- Independent of other cells
What make Eukaryotic cells unique
- varying sizes
- dominant nucleus
- highly structured
- contains membrane bound organelles
- Division of labor among organelles
- May form tissues
Give an example of a unicellular eukaryote
paramecium
___________ is a thin boundary separating the cell from its environment
the plasma membrane
The membranes of cells are composed of
- phospholipids
- proteins
The membrane acts as a boundary for
biochemical reactions
The membrane phospholipids are arranged in a double layer called the
phospholipid bilayer
The ___________ is the model that shows how phospholipids and protein molecules may drift through the membrane
the fluid mosaic