Midterm >:( Flashcards
https://docs.google.com/presentation/d/1MhPPQ2fIsGJawMd8tO7i8zYVQG4SUJNgdfzcuBcgpOo/edit#slide=id.p
What are the parts of a controlled experiment?
Dependent and independent variables, constants, hypothesis, and a control and experimental group
What makes a controlled experiment controlled?
Having a control and experimental group
What are dependent variables vs. independent variables vs. constants
Independent - the thing you are changing in the experiment
Dependent - the thing that changes in response to the changing of the independent variable
Constants - variables that stay the same throughout the experiment
What is the control group vs. experimental groups
Control group - the group in an experiment that nothing is changed in Experimental group - the group that includes the independent variable
What are the steps and order of the scientific method?
- Observing and asking questions
- Forming hypotheses
- Designing controlled experiments
- Collecting data
- Analyzing data and forming conclusions
Detail observing and asking questions
Take note of an event or process that leads to a question
Detail forming hypotheses
Make an inference, a logical interpretation for the question based on the information you already know, then form an explanation
Detail designing controlled experiments
Create an experiment in which only one variable is changed to prove your hypothesis right or wrong
Detail collecting data
Measure the change you were studying in the experiment and observe how your control and experimental groups were different
Detail analyzing data and forming conclusions
Organize your data, typically on a graph and using statistics, and decide whether your data proves or disproves your hypothesis and whether your hypothesis should be accepted or rejected
What kinds of data are used in science? Describe them
Qualitative - descriptions of what is happening
Quantitative - numbers/measurements of what is happening
What is a scientific hypothesis?
A logical, simple, and testable prediction/explanation of what is happening based on information you know and inferences you have made
What is a scientific theory?
A highly tested and reliable explanation of how or why natural events occur based on repeated and well supported observations and hypotheses
What is a scientific law?
A statement that describes what is happening in the natural world
Can theories become laws or vice versa? Can they change in other ways? How are they related?
No; laws can’t become theories, theories can’t become laws (because theories only describe why or how something happens, whereas laws describe what is happening, so they are fundamentally different)
Yes; theories can grow and change, and laws can be adjusted, though it’s rare
Developments in the study of a law or theory may affect developments in the other
Why is peer review important?
Other people who read your work can provide a different view point, help fact check, add additional information, check for bias, and check your math
Why is being unbiased important?
You want to be as accurate as possible, and if you are biased, you may read information differently in order to prove something you want to be true
What are the characteristics of life?
- Made of cells
- Can reproduce
- Have a genetic code
- Grow and develop
- Respond to stimulus in environment
- Maintain an internal balance
- Change over time
- Use energy
What characteristics are common in science?
Curiosity, skepticism, creativity, and open-mindedness
Why is curiosity important?
Scientists need to be curious enough about the world in order to ask questions and want to know answers
Why is skepticism important?
Scientists must be skeptical enough of their and others’ ideas in order to want to test theories to prove/disprove these ideas
Why is creativity important?
Scientists must be creative enough to come up with new ideas and answers and in order to design experiments to test these ideas
Why is open-mindedness important?
Scientists must be open-minded enough to accept new information that may go against their theories and to accept that sometimes, they might be wrong
How many cells must an organism have?
At least one (unicellular) or many (multicellular)
What are the types of reproduction?
Sexual - requires 2 parents
Asexual - 1 parent that makes a copy of itself
Is each genetic code fully unique?
No; all genetic codes are universal and similar, but certain parts are different in each, giving each organism its characteristics
What does it mean for an organism to grow and develop?
Must have different stages of life, e.g. an egg to a caterpillar to a butterfly or a baby to a kid to an adult
What are stimuli? How may it affect an organism?
Something that happens/a change in the environment that an organism reacts to; e.g. jumping (reaction) at a loud noise (stimulus)
Define homeostasis
The maintaining of a stable internal environment in an organism, e.g. sweating when hot/shivering when cold
Define evolution
Adaptations that arise in organisms over several (or possibly hundreds) of years
Are viruses living?
No; the only way they can check all the boxes for characteristics of life is if they are actively infecting a living thing
What is the metric system? Why do scientists use it?
The units of measurement used around the world; since all scientists use it worldwide, data can stay consistent. It’s also more precise and easier to convert
How do you convert units on the metric system, and what do decimals have to do with it?
Multiply/divide the measurement by 10 or move the measurement’s decimal place left to convert to a smaller unit and right to convert to a larger unit
What ladder can you use to convert units on the metric system?
Kilo- (K): 1000 units
Hecto- (h): 100 units
Deca- (da): 10 units
Base: 1 unit
Deci- (d): 0.1 units
Centi- (c): 0.01 units
Mili- (m): 0.001 units
What scientists contributed to cell theory?
Robert Hooke, Anton van Leeuwenhoek, Matthias Schleidan, Theodore Schwann, Rudolph Virchow
What did Robert Hooke do?
First person to observe and identify (dead) cells & named them (looked like cells monks lived in)
What did Anton van Leeuwenhoek do?
First person to observe living microorganisms and cells
What did Matthias Schleidan do?
First person to state that all plants are composed of cells
What did Theodore Schwann do?
Stated that all animals are composed of cells
What did Rudolph Virchow do?
Stated that all cells come from existing cells
What are the three parts of cell theory?
- All living things are made up of cells
- Cells are the basic units of structure and function in living things
- New cells are produced from existing cells
What are the two types of microscopes?
Compound light microscopes and electron microscopes
How do microscopes work?
Shine a focused beam of light or electrons onto the object to provide a magnified image
What microscope do you use for observing living things? Nonliving things?
Compound light microscope
Compound light or electron microscope
What are the two types of electron microscopes and what are they used for?
Transmission - study the internal cell structures
Scanning - study the surface of cells or organisms by producing a 3D image
What is a prokaryotic cell?
Small and simple cells that have free floating, circular DNA and ribsosomes, but no nuclei
What types of organisms are prokaryotes?
Bacteria and most, but not all, single-celled organisms
What is a eukaryotic cell?
Larger and more complex cells that have nuclei to hold their linear DNA, membrane-bound organelles, and membrane bound and free floating ribosomes
What types of organisms are eukaryotes?
Protists, fungi, plants, animals, all multi-cellular organisms, and some single-cellular organisms
What organelles are in animals?
Plasma membrane, ribosomes, cytoplasm (not technically an organelle), centrioles, nucleus, rough and smooth endoplasmic reticulums, golgi apparatus, [contractile] vacuole (but very small and often not shown in models), lysosomes, mitochondria
What organelles are in plants?
Plasma membrane, cell wall, ribosomes, cytoplasm (not technically an organelle), nucleus, rough and smooth endoplasmic reticulums, golgi apparatus, central vacuole, chloroplasts, mitochondria
Where is the membrane found? What does it membrane do?
Surrounding all types of cells
Controls what enters and leaves the cell
Where are the ribosomes found? What are they made of? What do they do?
Free-floating or on the rough ER of all cells
RNA
Make proteins
What does cytoplasm do? What is it made of?
Fills the cell and holds its components in place
Living jelly-like material
What are the types of genetic material?
DNA and RNA
Where is the cell wall found? What type(s) of cells are they found in? What is it made of? What does it do?
Outside the membrane of plant, fungi, and prokaryotic cells
Cellulose
Provides support and protection for the cell
Define selectively permeable. What is selectively permeable?
Allows some molecules to enter but not others
Cell membrane
What is the structure of the cell membrane?
Composed of a phospholipid bilayer, has two layers of molecules with a hydrophilic (water attracting) head and a hydrophobic (water repelling) tail. In the layer inside the cell, the head is pointing toward the center of the cell, but in the outside layer, the head is pointing away from the cell. The ends of the tails are connected to the outside of the cell
What is the cytoskeleton? What does it do? What is it made of?
The main component of cytoplasm, gives the cell its shape and capacity for movement
Microtubules, intermediate fibers, and microfilaments
What are microtubules? What do they do?
Hollow structures made up of proteins (tubulins)
Help maintain cell shape, form the mitotic spindle during cell division, and build projections called cilia and flagella on the cell surface
What are centrioles? What are they made of? Where are they found?
Paired structures that play a role in cell division
Microtubules
Outside the nucleus, mostly in animal cells
What is the nucleus? What does it contain? What is a main part of it? What does it make?
The control center of the cell
Chromatin, which separates into chromosomes during cell division
Nucleolus
Ribosomes
What is the endoplasmic reticulum?
A complex network of membranes that produces protein (rough ER) and lipids (smooth ER) and transports them to their next destination in the cell
What does the golgi apparatus do? How? Other name?
Packages molecules made in the smooth and rough ERs
Forms sacklike structures called vesicles that surround the surround the molecules and take them to the membrane to be released outside the cell
Golgi bodies
What does the vacuole do? Where is it found?
Contains enzymes, stores nutrients and waste products, and regulates the water contents of cells
In plant and animal cells, but much larger in plants
What do lysosomes contain? What do they do? Where are they found?
Digestive enzymes
Break down large food molecules and worn out cell parts
Only in animal cells
What do chloroplasts contain? What does it do? What type(s) of cells are they found in?
Contains chlorophyll that captures energy from the sunlight and convert it into food that contains chemical energy that the cell can use
Only plant and algae cells
What does the mitochondria do?
Converts chemical energy from food into compounds that the cell can use
