Chapter 1 – The Science of Biology
2. Quantitative vs. qualitative observation
• Qualitative observation is generally more subjective, while quantitative observation is more objective.
• Qualitative observations go through a constant process of analysis while being gathered; quantitative observations are analyzed after data is collected.
• Qualitative observations are most often performed in field observations using natural settings, while quantitative observations are better suited to a controlled laboratory environment.
3. Steps of the scientific method
1) Stating the Problem
2) Forming a Hypothesis
3) Setting Up a Controlled Experiment
4) Recording and Analyzing Results
5) Drawing a Conclusion
4. Experiments of Redi, Needham, Spallanzani, and Pasteur
In 1668, Francesco Redi, an Italian physician, proposed a different hypothesis for the appearance of maggots. Hypothesis: Flies produce maggots. Redi controlled all variable but one—whether or not there was gauze over each jar. Conclusion: Maggots form only when flies come in contact with meat. Spontaneous generation of maggots did not occur.
Anton Van Needham claimed spontaneous generation could occur under the right conditions. To prove his claim, he sealed a bottle of gravy and heated it. He claimed that heat had killed any living things that might be in the gravy. After several days, he examined the contents of the bottle and found it swarming with activity. “These little animals,” he inferred, “can only have come from juice of the gravy.”
An Italian scholar, Lazzaro Spallanzani, decided Needham hadn’t heated his samples enough and decided to improve upon Needham’s experiment. He boiled two containers. He sealed one jar immediately and left the other jar open. After a few days, the gravy in the open jar was teeming with microorganisms. The sealed jar remained free of microorganisms.
In 1864, an ingenious French scientist, Louis Pasteur, develops the first vaccine penicillin against anthrax, a deadly bacterial disease that affects both animals and humans
5. Characteristics of life
Living things are made up of units called cells.
Living things reproduce.
Living things are based on a universal genetic code.
Living things grow and develop.
Living things obtain and use materials and energy.
Living things respond to their environment.
Living things maintain a stable internal environment.
Taken as a group, living things change over time.
6. Cell specialization
Cell specialization is when cells specialize in certain duties, such as when blood cells carry nutrients; skin cells protect the interior of the body, etc.
7. When do you use a compound light microscope, TEM, or SEM?
Compound light microscopes allow light to pass through the specimen and use two lenses to form an image. In addition to studying specimens of dead organisms or their parts, light microscopes make it possible to observe some tiny organisms and cells while they are still alive.
Electron Microscopes focus beams of electrons on specimens. These microscopes can form images of objects 1000 times smaller than those visible under a light microscope. Biologists use two main types of electron microscopes. Transmission electron microscopes (TEMs) shine a beam of electrons through a thin specimen. Scanning electron microscopes (SEMs) run a pencil-like beam of electrons back and forth across the surface of a specimen.
Chapter 3, 4-2, 5, and 6-3 – Ecology Unit
2. The equation for photosynthesis
The photosynthesis equation is as follows:
6CO2 + 6H20 + (energy) → C6H12O6 + 6O2
Carbon dioxide + water + energy from light produces glucose and oxygen
3. How is the movement of energy different from that of nutrients?
Nutrients cycle through ecosystems because the earth is a closed system with regards to nutrients. So, we don't get any new input of carbon, nitrogen, water, etc. (except for some minimal input from meteors).