CELL THEORY
1. How did Janssen's, Hooke's, and Leewenhoek's work contribute to the work of the scientists that came after them?
Zacharias Jansen and his dad, Hans experimented with lenses. They put several lenses in a tube and discovered microscope. It allows English scientist Robert Hooke to use the microscope to discover cells in 1665. However, Hooke still didn’t know their real structure and function. Anton Van Leeuwenhoek build microscopes that was inspired by the glasses used by drapers to inspect the quality of cloth, the microscopes are considered the first practical microscopes.
These discoveries of cells and microscopes helps scientist to discover more stuff related with cells, organisms, and others. After those three scientists, more people like Robert Brown discovered nucleus in plant cells. The cell theory is from Theodor Schwann and Mathias Jakob Schleiden in the 1830s. All these discoveries helps more scientist to find out about diseases from cells and microorganisms and bacterias in human body.
2. How would our lives be different if we had never realized the existance of microorganisms? Provide at least one example to support your answer.
Microorganisms are everywhere, it is the start of a living thing. Microorganisms are in plants, animals, and human. Even though it can be harmful, it can also be beneficial for lives. Microorganisms like bacteria helps digestive system to work better. Without realizing the existence, we wont understand about how our or any other living thing work. One example of microorganism is photosynthetic bacteria. It is a bacteria that can photosynthesize so they could survive on their own. It produces useful substances like amino acids, nucleic acids, and bioactive substances that are very important and useful for living things. So without realizing the existence of microorganisms, it will make our life harder. It will be the opposite of what we have now, not knowing anything.
3. Describe the concept of spontaneous generation. Why do you think it took such a long time for people to accept that this idea was incorrect?
People used to believe that living things come or are produced from non living things like how maggots come from rotting meat and fish comes from mud from dried lakes. I think that whyit took such a long time is because people believed it that way and only observed based on what they see, they didn’t really research or discover carefully until a few experiments are conducted to disprove the spontaneous generation.
4. How do you think the cell theory impacted later scientific discoveries? Explain your answer.
Before, there are only three points in the cell theory, which later on was added three more after discovering DNA. The cell theory tells us that all living organisms are composed of cells and that cell is the basic unit of life. It proves that every living thing is made up of one or more cells. Scientists can now find out more about organisms that they couldn’t have if they didn’t know about cells (and that the spontaneuos generation is incorrect). The cell theory helps study cells with microscopes and other advanced technology.
5. The microscope and numerous experiments lead to the rejection of spontaneous generation. This idea had been accepted by most people, including scientists, for over 200 years. How does this demonstrate the true nature of science?
The true nature of science is about hypothesis, theories, facts, observations, research, and failures. People believed the spontaneous generation based on what they see and observed. It is possible for them to make that kind of theory and believed it since no one has find out or discover more about it. Since the true nature of science includes observations and failures, it is possible for people to believe the concept of spontaneous generation because the only prove they have is based on their observations, which lasts for over 200 years.
6. Review Pasteur's experiment. Relate his experiment to the scientific method.
Pasteur does his experiment based on the scientific method. He first started by forming a question he wants to answer by the end of the experiment, “where do the microbes come from to cause broth to decay?” He then research more about it and find out more about flasks and found out that microorganisms appeared in the straight necked flasks, not in the sealed or swan necked flasks. After researching, Pasteur stated his hypothesis, “live microorganisms suspended in air could settle onto the broth in open-necked flasks via gravity. He did his experiment using various flasks and concluded his experiment.
a. What was Pasteur's question?
Where do the microbes come from to cause broth to decay?
b. State a reasonable hypothesis based upon this question.
Live microorganisms could settle onto the broth in open-necked flasks because of gravity.
c. What was the independent variable in Pasteur's experiment? What was the dependent variable?
The independent variable is the design of the flask. The dependent variable is the growth of the microorganisms.
d. What did Pasteur conclude from his experiment?
The broth in the broken flasks became cloudy, it is a sign that it teemed with microbal life. The broth in the unbroken flasks remained clear. Dust particles could not travel against gravity into the flasks and so the unbroken flasks did not get affected by the dust which produces microbes. Thus, the Louis Pasteur experiment refuted the notion of spontaneuos generation.
7. Examine your timeline. How long did it take to develop the cell theory? What does this imply about the formulation of a theory?
It took more than 200 years to develop the cell theory. From discovering cells by the invention of microscopes to knowing that all animals and plants are made of cells, it took a long time to process all the data and information from the research and observation from all the scientists that “participated” on formulating the theory. A theory is a way to interpret facts from research, to be able to prove something needs a lot of time for research to know the actual result. Which is why the cell theory needs more than 200 years to be formed.
8. Why do we still consider the cell theory a theory? Explain your answer.
Theory in science is a way for us to explain the facts using proof from research and observation. It means that the cell theory is a way for scientists to interpret facts. We consider the cell theory a theory because it is the facts that scientist has proven from their research and observations through the years, and no scientists has proven a disagreement towards the theory.
RESOURCES
https://www.preceden.com/timelines/46013-contributions-to-cell-theory
http://www.history-of-the-microscope.org/history-of-the-microscope-who-invented-the-microscope.php
http://www.microscopemaster.com/cell-theory.html
http://www.smithlifescience.com/celltheory.htm
https://biology.knoji.com/examples-of-beneficial-microorganisms-and-what-they-do/
https://www.infoplease.com/science/biology/origin-life-spontaneous-generation
http://edtech2.boisestate.edu/pattymcginnis/506/cell_site/506_cell_theory.html
https://www.livescience.com/21491-what-is-a-scientific-theory-definition-of-theory.html
http://www.pasteurbrewing.com/louis-pasteur-experiment-refute-spontaneous-generation/
http://www.visionlearning.com/en/library/Hidden/59/Experimentation-in-practice/171