Bio - package 1 Flashcards
What is abiogenesis or spontaneous generation?
A theory which states that living things can be produced from non-living matter
What was Francesco Redi’s experiment?
Two jars containing meat were placed in an area containing flies. One jar was covered in a cloth which allowed air but not flies to pass through, and the other jar was completely open. Only the open jar developed maggots
What was the objective of Louis Pasteur’s experiment?
To refute the claim that as microorganisms could not reproduce in a manner similar to maggots, they must be produced by spontaneous generation
What was Louis Pasteur’s experiment?
Pasteur filled flasks with a long S-shaped neck with nutrient-rich broth and boiled it to kill all organisms within it. As the organism-containing air settled in the neck due to gravity, the air did not reach the broth. The broth remained clear (indicating no organisms), however when the flask was tilted the broth became cloudy
What is biogenesis?
The theory that living organisms could only arise from other living organisms
How did Robert Hooke contribute to the formation of cell theory?
Hooke looked at slices of cork under a crude microscope (about 30x magnification) and saw “empty rooms” which he named cells. The “empty rooms” were actually walls of dead cells
How did Antony van Leeuwenhoek contribute to the formation of cell theory?
van Leeuwenhoek produced high-quality lenses (about 500x magnification) and observed the first single-celled organisms. This led him to be referred as the “father of microscop
How did Matthias Schleiden contribute to the formation of cell theory?
Schleiden observed plant material from various species and concluded that all plants contained cells or cell components. He also observed cell nuclei and concluded that cells must develop from the nuclei
How did Theodor Schwann contribute to the formation of cell theory?
Schwann observed animal tissue from various species and made the connection along with Schleiden that he had observed nuclei in animal tissue, and animal tissue must contain cells. Proposed the claim that “all organisms contain cells”.
What are the 3 parts of the Cell Theory?
- All organisms are composed of one or more cells
- The cell is the smallest functional unit of life
- All cells are produced from other cells
What are the 8 functions of life which all living things carry out?
Organization - being structurally composed of cells
Metabolism - all chemical reactions occur within the organism
Growth - organism increases in size
Reproduction - produces new individual organisms
Response - responding to environmental stimuli
Homeostatis - maintaining a constant internal environment
Nutrition and Excretion - taking in nutrients and expelling wastes
Adaptation - changing over a period of time to adapt to the environment
What are the characteristics of the Modern Light Microscope?
Visible light is passed through the specimen and then through one or two lenses, which refract light to produce a larger image. If one lens is used, it is a simple microscope (and a compound microscope otherwise)
What are the characteristics of the Dissecting Microscope?
A binocular microscope which is used where a large distance bwteen stage and lenses are required. It can produce a 3-D view due to the two lens systems, and usually has an extremely low magnification (5-6x)
What are the characteristics of the Fluorescence Microscope?
Specimens are treated with fluorescent molecules which emit light of different wavelengths. It is used to only look at one specific part of cells or other specimens. Its magnification is up to 2,000x
What are the characteristics of the Transmission Electron Microscope?
A beam of electrons is passed through a very thin section of the specimen, and the electrons which pass through the specimen are detected on photographic film. It produces very clear images of specimens’ interiors and magnify from 10,000x to 100,000x
