Biology Unit #3 Flashcards
Cells
A cell is the most basic unit of life which all organisms are made of
Theory
An educated guess/hypothesis that hasn’t yet been proven wrong; an explanation
Robert Hooke
1666 - discovered cells by looking at a thin sliver of cork under a microscope
Anton van Leeuwenhoek
1673 - used a handmade microscope to observe pond scum and discovered single celled organisms
Francisco Redi
- proved spontaneous generation is false with meat and maggots
Louis Pasteur
- proved that living things come from other living things
Matthias Schleiden
1838 - discovered that all plants are made of cells
Theodor Schwann
1839 - discovered that all animals are made of cells
Rudolf Virchow
1858 - concluded that all cells are made of preexisting cells
Spontaneous Generation
The theory that living things come from nonliving things
Cell Theory
- all organisms are made of one or more cells and all cells come from preexisting cells
- Cells are the basic unit of life
- Cells have specialized structures and functions
Microscope
A tool used to magnify small objects
MAgnification
The enlarging of an object
Hans and Zacharias Janssen
Created the first microscope which as later improved by Leeuwenhoek
Compound Light Microscope
Uses light and a series of lenses to magnify an object (2D)
Scanning Electron Microscope
Sweeps a beam of electrons over an object to produce a 3D image
Transmission Electron Microscope
Shoots a beam of electrons through an object to create a very detailed 2D image
Scanning Tunneling Microscope
Can show the atoms on an object’s surface
Unicellular
Single celled (bacteria)
Multicellular
Multiple cells (animal, plant, fungi)
How do the cells in multicellular organisms combine?
Atoms - Compounds/Biomolecules - Organelles - Cells - Tissues - Organs - Organ Systems - Organism
Tissues
A group of similar cells grouped together
Organ
Different tissues grouped together
Organ System
Several organs and tissues working together
Organelle
A structure in a cell with a specific function
Cell Membrane
Surrounds and protects the cell, controls what goes in and out
Cytoplasm
The clear jelly-like fluid that surrounds the organelles and holds them in place
Nucleus
The controls cell activity and stores DNA
Nucleolus
Inside of the nucleus making ribosomes
Ribosomes
Links amino acids together to make proteins
Endoplasmic Reticulum
Has a folded membrane found near the nucleus
Smooth ER - makes fats/lipids
Rough ER - where ribosomes attach
Golgi Body/Apparatus
Modifies, sorts, and packages proteins
Vacuoles
Stores things like food , waste, enzymes, and waste
Lysosomes
Has digestive enzymes and are the cells garbage men
Mitochondria
Transforms energy for the cell; powerhouse of the cell
Cytoskeleton
Made of rods and filaments that form the framework
Centriole
Helps in cell division (only in animals)
Chloroplasts
Changes sunlight into energy (only in plants
Cell Wall
A rigid structure that surrounds and protects the cell membrane
Amyloplast
Converts glucose into starch and then stores it
Cilia
Short hair like extensions that help with movement
Flagella
Longer whip-like projection that helps with movement
