2.1: Cell Theory Flashcards
What are the 3 main principles of cell theory?
All organisms are composed of one or more cells Cells are the smallest units of life All cells come from pre-existing cells
What has helped to gain credibility for the cell theory?
the microscope
What did Robert Hooke do and in what year?
1665, First observed cells looking at a piece of cork under a microscope he built
Who first observed cells looking at a piece of cork under a microscope he built in 1665?
Robert Hooke
What did Antonie van Leeuwenhoek do and in what year?
observed first living cells under a microscope in 1670
Who observed first living cells under a microscope in 1670?
Antonie van Leeuwenhoek
What were the 4 types of cell Antonie van Leeuwenhoek observed?
protozoa, bacteria, spermatozoa, and muscle fibers
What did Antonie van Leeuwenhoek refer to cells as?
animacules
Who referred to cells as animacules?
Antonie van Leeuwenhoek
What did Mathias Schleden say in 1838?
Plants are made of “independent, separate beings”
What did Louis Pasteur do in the 1860’s?
Boiled chicken broth and showed living organisms would not spontaneously reappear
What are the 6 functions of life?
metabolism, growth, reproduction, homeostasis, response, nutrition
What is metabolism?
all chemical reactions that occur in organisms
What are all chemical reactions that occur in organisms?
metabolism
What is growth?
always evident in some way
What is always evident in some way?
growth
What is reproduction?
hereditary molecules passed to offspring
What is hereditary molecules passed to offspring?
reproduction
What is homeostasis?
maintaining constant internal environment
What is maintaining constant internal environment?
homeostasis
What is response?
essential for survival
What is the essential for survival?
response
What is nutrition?
using compounds to provide energy to organisms
What is using compounds to provide energy to organisms?
nutrition
How does a light microscope work?
light passes through the specimen to form an image
How does an electron microscope work?
electrons pass through a specimen to form an image
What is the size of most cells?
100 micrometers
What is the size of organelles?
10 micrometers
What is the size of bacteria?
1 micrometer
What is the size of viruses?
100 nano-meters
What is the size of the cell membrane (thickness)?
10 nano-meters
What is the size of molecules?
1 nano-meter
How do you determine the magnification?
size of image/size of specimen
Why don’t cells keep growing?
surface area to volume ration limits the size of sails
What controls what enters and exits the cell?
cell membrane
What type of cells can move more materials in and out of the cell?
cells with higher surface area to volume ratios
What is the relationship between cell size and surface area?
inverse (large cell have a low surface area and small cells have a high surface area)
What is the process cells go through to become multiple cell types?
Cell Differentiation
What are two types of cells that lose the ability to reproduce once they differentiate?
nerve cells and muscle cells
What is the difference between stem cells and other types of cells?
stem cells Retain the ability to divide and differentiate into various cell types
Where are plant stem cells located?
meristematic tissue near roots
Where are animal stem cells located?
embryo
What type of microscope?
light
What type of microscope?
electron
