Cells and Microorganisms Flashcards
What is the Independent variable
You design a study to test whether changes in room temperature have an effect on math test scores.
Your independent variable is the temperature of the room. You vary the room temperature by making it cooler for half the participants, and warmer for the other half.
The independent variable is the variable you set yourself. Its called “independent” because it is not affected by any other variables - its only affected by you. It goes along the X axis (along the bottom). Independent variables are usually things you set like time, size, temp, etc.
What is the Dependent variable?
You design a study to test whether changes in room temperature have an effect on math test scores.
Your dependent variable is math test scores. You measure the math skills of all participants using a standardized test and check whether they differ based on room temperature.
The dependent variable is the variable you measure the changes of. This variable is affected by the independent variable (presumably) and thus is called the independent variable. It goes on the Y axis (along the side).
What are constant Variables?
Controls. something you keep the same in your experiment so the results don’t change for other reasons than you are measuring.
What is Validity?
How well the data you’ve observed measures what it is supposed to.
“What is validity? Validity relates to the experimental method and how appropriate it is in addressing the aim of the experiment: “
What is Accuracy?
Accuracy is how close the data is to its true value/what it should look like.
Relationship between Precision and Accuracy?
Precision is how close together your data points are.
Accuracy is how close the data is to its true value/what it should look like.
Your data points could all be scattered (imprecise), but if the average of the data is close to the true value, it is still accurate.
Likewise, your data points could all be very similar (precise) but it could be different from the true value, and therefor be inaccurate.
What is Precision?
Precision is how close together your data points are. Scatter is how far they are apart. High scatter means they are far apart, and imprecise. Vise versa.
What are random errors?
Random errors are errors that randomly displace results. Things that could have effected results.
How can you fix random errors?
By keeping a controlled environment, keeping constant variables, and using the same method. try to keep the same and don’t let any external factors influence your experiment.
What are systematic errors?
Systematic errors are errors that displace your results at a set rate. For instance, a temp of 36 degrees could be constant for your experiment, but still displace your results from their true value, making them inaccurate.
How can you fix systematic errors?
By repeating the experiment on another day, using different equipment, but still measuring/doing the same things.
How to write a hypothesis?
Use the If… then…* method.
If the SA:V ratio is increased, then the rate of diffusion will also increase.
Your hypothesis is an educated guess. It is not infallible, and any data you collect cannot “prove” your hypothesis or “disprove” your hypothesis. Either data does or does not support your hypothesis.
A hypothesis is a theory that is used under the assumption that it is true.
What is cell theory?
The Cell Theory Is a Unifying Principle of Biology
The cell theory states that all biological organisms are composed of cells; cells are the unit of life and all life come from preexisting life.
What is the difference between Multicellular and Unicellular organisms?
Unicellular means “one cell”. These organisms are made out of one cell, and are sometimes called Prokaryote cells (but not all unicellular organisms are prokaryotic). They can use flagellum (little tails) to move around. They use binary fission to reproduce.
Multicellular means “many cells”. These organisms are made out of many cells, and are pretty much Eukaryotes. They use organs and limbs to move around. They use mitosis to grow, and sometimes miosis to reproduce.
What are the processes all living things do? Hint: MRS GHREN
Movement
Respiration (on a cellular level)
Sensitivity (responding to stimuli)
Growth
Homeostasis (keeping environment suitable)
Reproduction
Excretion
Nutrition
Not all of these are done by all living things (viruses for instance, are not classified as living, but they reproduce, grow, move, respond to stimuli, etc.).
Light vs electron microscope.
Light microscope has less zoom (larger size picture) and low resolution the more zoom. It uses light to reflect back at what it hits to see.
Electron microscope has much more zoom and resolution/detail of images. It uses electrons fired at an object (which must be dead and prepared in a certain way) to see it.
Parts of a light microscope?
Please look at a diagram.
https://microbenotes.com/light-microscope/
The parts are (from top to bottom):
-Eyepeice
-Arm
-Nosepeice
-Objective Lens (3x)
-Clips
-Stage
-Diaphragm
-Course adjustment
-Fine adjustment
-Light source
-Base
How to make a wet mount slide
“A wet mount is made by placing a fluid solution on a slide, suspending a specimen in a solution, and then covering the specimen and the solution with a cover slide. Why would use a wet mount? To increase the specimens translucency and to make it easier to stain.”
*specimen then water droplet
Umanitoba.ca. (2022). Available at: https://www.umanitoba.ca/outreach/crystal/Support%20Files/Experimental%20Skill%20Development/Preparing%20a%20Wet%20Mount%20-%20Experimental%20Skill%20and%20Investigation.doc#:~:text=A%20wet%20mount%20is%20made.
What cell parts can be observed through a light microscope?
Cell membrane, Nucleus.
Can you estimate cell size using a measure and microscope zoom?
Yes! first you need to find out what zoom you are on, and have a measure across the plate you are looking at. We usually measure in micrometers.
Say your zoom is at 400% and a measure of 5 microns goes across a third of the FOV (field of view - the entire picture). This means that 5 microns is a third of the FOV, so the entire FOV is 15 microns. Then when we look at a cell that goes across 2 thirds of the FOV (still at 400%), we can estimate it is 10 microns.
Remember to keep zooms consistent, and it is always an estimation.
What is a Prokaryotic cell?
“A prokaryote is a single-cell organism whose cell lacks a nucleus and other membrane-bound organelles.”
What is a Eukaryotic cell?
“The eukaryotes constitute the domain of Eukarya or Eukaryota, organisms whose cells have a membrane-bound nucleus. All animals, plants, fungi, and many unicellular organisms are eukaryotes.”
What cell parts do Animal cells have?
Nucleus, Mitochondria, Golgi body, Cell membrane, Rough and smooth ER, Ribosome, Lysosome, Cytoplasm.
Sometimes a small Vacuole.
What cell parts do Plant cells have?
Nucleus, Mitochondria, Golgi body, Cell membrane, Rough and smooth ER, Chloroplast, Vacuole, Cell Wall, Ribosome, Lysosome, Cytoplasm.
What is the function of a Nucleus?
To store the DNA for a cell, and thus the instructions to create proteins.
What is the function of a Mitochondria?
The mitochondria is the site of aerobic respiration (turning O2 and Glucose into CO2, H2O, and energy for the cells activities)
What is the function of a Golgi Apparatus/Body?
“The three primary functions of the Golgi apparatus are the transport, sorting and modification of both protein and lipid, and the protein composition of the organelle reflects these functions.”
What is the function of a Cell Membrane?
To separate the cell from its external environment. IT also acts as a mode of filtering what materials get to pass into and out of the cell.
