Term 1
Review 1
How did Janssen's, Hooke's, and Leewenhoek's work contribute to the work of the scientists that came after them?
These three scientists contribute on the evolution of microscope. Their work gives the scientists that came after them the ability to observe and analyze things that are too small for the human eye.
How would our lives be different if we had never realized the existence of microorganisms? Provide at least one example to support your answer.
If we had never realized their existence, the food industry, health industry, agriculture industry, and other industry wouldn’t be as advanced as it is now. For example, the fermentation process uses microorganism such as yeast, mould, and bacteria. Without the knowledge about the existence of microorganism,we wouldn’t be able to use the fermentation process.
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?
It is a theory that states that living organisms were produced from nonliving things. The theory was accepted by people because of many things. One of the reasons was because of the invention of microscope. Its invention revealed that there are organisms that spontaneously produced.
How do you think the cell theory impacted later scientific discoveries? Explain your answer.
The cell theory gives us a better understanding of organisms. Because of this theory, we know that every organism is consisted of one or more cells. With this knowledge, we can learn more about organism by learning about their cells’ functions.
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?
It shows that science is about developing theories. These theories might be proven right today, but in the future these theories can be proven wrong. This is what science is about. Testing and developing theories.
Review Pasteur's experiment. Relate his experiment to the scientific method.
a. What was Pasteur's question? State a reasonable hypothesis based upon this question.
Can a living being only produce molecules that are of a specific orientation?
Yes, because it can only create something that’s already been made
b. Can living organisms only produce molecules that are of one specific orientation?
yes
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c. What was the independent variable in Pasteur's experiment? What was the dependent variable?
The independent variable was whether or not the flask had a curved or straight neck. The dependent variable was whether or not the broth showed any growth.
d. What did Pasteur conclude from his experiment?
He concluded that the spontaneous generation theory is wrong and that microorganism is everywhere
Examine your timeline. How long did it take to develop the cell theory? What does this imply about the formulation of a theory?
190 years. This shows that a theory can be improved over time and is not only developed by one person. People can improve a theory if they’re proven right.
Why do we still consider the cell theory a theory? Explain your answer.
Because the cell theory has a loophole, which is “if all cells are made from other cells, how is the first cell made? “.
Cells Analogy
If I have to compare plant cell system with anything, I would compare it with a company/office. I think so because cells works together with each other to make sure that the organism they are on works correctly. If any of the cells doesn't work, the organism's functionality would be fatally hindered. Cells also have all different kind of functionality, such as hormone secreting cells, exocrine secretory epithelial cells, and etc. This system is really similar with the system that every company have where they have a lot of divisions each having different functionality, such as economy and marketing division where if one of the division fails, the others would also fail, which in turn would make the whole company fail.
-The nucleus can be called the boss of cells. Just like bosses in companies, nucleus is the one giving command. They analyze the functionality of the body/company that they’re on. They make sure that the cells/workers do their job properly. Without boss/nucleus, the cells won’t know what to do making the organism/company fails.
-Cytoplasm can be compared to an office. It’s the place where everything resides. Cells/workers do their job in there. They also separate the all the cells from the outside.
-Cell membrane and cell wall are like the security for cells. It decides what can get through and what cannot.
-Mitochondria and ribosomes are similar to investors. They gives energy/money to allow the company/cell system to work.
-Chlorophyll can be called the workers of the cells. They make food to provide energy for plants just like workers makes products for businesses.
-vacuole is like the OB of a company. They isolate harmful materials, store waste products, store valuable water in a plant cell, and etc. This is very similar to OB’s job where they’re the ones who clean the office and store the company’s stuff in the warehouse.
Mitosis Reflection
Dictionary Definition
Interphase: The period of the cell cycle during which the nucleus is not undergoing division, typically occurring between mitotic or meiotic divisions
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G1 Phase: The first growth period of the cell cycle, during interphase, in which the cell grows and cytoplasmic organelles are replicated.
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S phase:The period of the cell cycle prior to mitosis, during which the chromosomes are replicated
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G2 Phase: The second growth period of the cell cycle, following DNA replication and preceding prophase, during which the cell forms the materials that make up the spindle.
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Prophase: The first stage of mitosis or meiosis in eukaryotic cell division, during which the nuclear envelope breaks down and strands of chromatin form into chromosomes.
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Metaphase: The stage in mitosis or meiosis in which the duplicated chromosomes line up along the equatorial plate of the spindle.
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Anaphase: The stage in mitosis or meiosis following metaphase in which the daughter chromosomes move away from each other to opposite ends of the cell.
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Telophase: The final stage of meiosis or mitosis, in which the separated chromosomes reach the opposite poles of the dividing cell and the nuclei of the daughter cells form around the two sets of chromosomes.
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Cytokinesis: The division of the cell cytoplasm that usually follows mitotic or meiotic division of the nucleus.
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Chromosome: Any of several threadlike bodies, consisting of chromatin, that carry the genes in a linear order: the human species has 23 pairs, designated 1 to 22 in order of decreasing size and X and Y for the female and male sex chromosomes respectively
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Chromatid: One of two identical chromosomal strands into which a chromosome splits longitudinally preparatory to cell division.
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Centriole: A small, cylindrical cell organelle, seen near the nucleus in the cytoplasm of most eukaryotic cells, that divides in perpendicular fashion during mitosis, the new pair of centrioles moving ahead of the spindle to opposite poles of the cell as the cell divides: identical in internal structure to a basal body
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My Definition
Interphase: The process where they prepare for a cell to divide
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G1 Phase: The process where the organelles in a cell gets duplicated to prepare itself for mitosis.
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S phase:The process where DNA gets duplicated and when it's on the checkpoint, it gets corrected.
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G2 Phase: The process where enzymes get made for mitosis and check for errors that ha.
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Prophase: The process where centriole and spindle fibers get made and nucleus disappear.
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Metaphase: The process where the chromosomes gets attached with spindel fibers and get aligned.
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Anaphase: A process where the chromosomes and its duplicate gets split into two
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Telophase: A process where the cells started divide and nucleus starts to appear
Cytokinesis: Where the mitosis ends and the cell becomes 2 cells
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Chromosome: A form of DNA that contains our genetic materials
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Chromatid: The duplicate of a chromosome
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Centriole: An organelle that helps cell division
Experiment on Potatoes in Saltwater and Potatoes in Freshwater
Introduction
In this experiment, we experimented on potatoes to see the difference between when they're put in saltwater and when they're put in freshwater. I hypotesize that if we put potatoes in saltwater, the potatoes would gain weight and be heavier that potatoes in freshwater since it will absorb the salt and water, becomes hard, and would make the water lose the salt. If we put the potatoes in freshwater, I think the potatoes would also gain weight, but will not have as heavy as potatoes in salt water since it will only absorb the water, will have the same flexibility, and the water will stay the same.
Procedure
In this experiment, we used four materials, which are:
- potato
-2 bowls
-salt
-knife
Steps:
1. Get 2 bowls and fill both with water
2. Get salt and put tablespoon amount of it in one of the bowl
3. Cut the potatoes into 6 pieces (shape should be like french fry)
4. Put the 3 potatoes in both bowl
5. Wait for one hour
6. Check the potatoes (mass,characteristic, and difference)
Potato Mass
No salt Salt
14.7g-15.29g 17.3g-15.9g
23.2g-23.8g 32.1g-30.8g
26.5g-27.3g 27.1g-25.2g
19.2g-19.9g 18.9g-16.6g
24.9g-25.7g 29.6g-28g
Result
In our class, we compiled all of the data from the experiment that all of the different groups did to make sure that the results of the experiment is credible. From the compiled data, we can confirm if hypotheses that I made before the experiment is wrong or right. The first hypothesis that I came up with is that if we put potatoes in saltwater, the potatoes would gain weight and be heavier that potatoes in freshwater since it will absorb the salt and water, becomes hard, and would make the water lose the salt. This hypothesis is proven to be wrong, since most of the potatoes weight decreases after being put in the salt water for an hour. This happens because the salt decreased the water concentration in the water. The salt prevents water from going in the potato since its water concentration is too low. Not only that, the salt also make the water from the potato to move out. This explains why the weight if the potatoes decreases. It also debunked my hypothesis about potatoes absorbing water and salt.
Proposal Biolit group 6
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Review for term 1
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Reflection: In term 1 of Biology, we’re learning about cells. We learned about its theory, types, components/organelles and their function, and so on. We focus more on some of the system, which are mitosis and cell respiration. We did an experiment for mitosis, where we try and put potato in 2 different containers, 1 container contain water with salt while the other only contain water.
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Things to improve: In the future, I hope that I’ll be more diligent when learning and focus on the lesson the teacher is explaining. I also hope that I can answer assessment more efficiently, where I can write less but explain more.