Unit 1A - Cells, Scientific Method, Safety, Transport Flashcards
Homer notices that his shower is covered in strange green slime. His friend Barney tells him that coconut juice will get rid of the green slime. Homer decides to check this out by spraying half of the shower with coconut juice. He sprays the other half of the shower with water. After 3 days of the “treatement”, tehre is no change in the appearance of the green slime on either side of the shower.
Identify the control gorup, independent variable, dependent variable, and what the conclusion should be.
Control Group - the side of the shower sprayed with water
Independent Variable - which liquid was used for cleaning
Dependent Variable - whether or not the green slime went away
Conclusion - coconut juice does not get rid of green slime
Bart believes that mice exposed to microwaves will become extra strong. He decides to perform this experiment by placing 10 mice in a microwave for 10 seconds. He compared these 10 mice to another 10 mice that had not been exposed. His test consisted of a heavy block of wood that blocked the mouse food. He found that 8 out of 10 of the microwaved mice were able to push the block away and 7 out of the 10 non-microwaved mice were able to do the same.
Identify the control group, independent variable, dependent variable, and what the conclusion should be.
Control Group - non-microwaved mice
Independent Variable - the microwaves
Dependent Variable - mouse strength
Conclusion - the microwaves did not increase the strength of the mice to any noticeable degree
How many variables do scientists test at a time?
Why?
Scientists test one variable at a time.
This allows them to isolate the variable and make sure that the effect observed in the experiment are the result of the one variable.
Scientists publish their results in order to
- Verify their procedures
- Receive feedback
- Verify their data
Which is the smallest level of organization that includes living things?
Cells
Of the following levels of organization, which level includes all of the other levels?
Cells, Ecosystem, Community, Organ System, Population
Ecosystem
Name the 8 characteristics of living things
All living things:
- Contain cells 2. Have DNA
- Obtain and use energy
- Reproduce 5. Respond to stimuli
- Maintain homeostasis
- Grow and develop 8. Evolve
What is homeostasis? (be able to name examples of how organisms maintain this)
Maintaining relatively stable internal conditions
Monosaccharides are monomers of
Carbohydrates
Through what type of reaction are polymers of carbohydrates formed?
Dehydration Synthesis
Nucleic Acids are made up of nucleotides, which include
A five-sided sugar, a phosphate, and a nitrogenous base
The biomolecule responsible for heredity including hair color, skin color, eye color, etc., is
Nucleic Acids
The long term energy source of living things is
Lipids (fats)
Molecules that end in -ASE are
Proteins
How do enzymes speed up the rates of reactions?
By lowering the activation energy
(the energy required for the reaction to take place)
Bread, pasta, fruit, vegetables, and sugars are all examples of
Carbohydrates
Which of the four biomolecules can you not obtain through food?
Nucleic Acids
What is cell specialization?
Cells in a multicellular organism do different jobs
Which scientists contributed to cell theory?
Schleiden, Schwann, and Virchow
The three main components of cell theory are
- All living things are made of cells
- Cells are the basic unit of life
- All cells come from existing cells
How do specimen observe under a compound light microscope differ from an electron microscope?
Light - living
Electron - dead/nonliving
Which organisms fall into the category of eukaryotes?
Protists, fungi, plants, and animals
All prokaryotes are
Bacteria
Compare and contrast prokaryotes and eukaryotes
Prokaryotes: no nucleus, older, all bacteria, smaller, simple, no membrane-bound organelles, unicellular
Eukaryotes: have a nucleus, have membrane-bound organelles, larger organisms than bacteria, contains unicellular and multicellular organisms (protists, fungi, plants, animals)
Organelles found only in plants (not animals) include
Chloroplast - photosynthesis
Large Central Vacuole - turgor pressure
Cell Wall - ^^ and protection
List the parts of the cell membrane and their function
Phospholipid - makes up the bilayer
Proteins - transport, recognition, attachment
Cholesterol - stabilizes the membrane and gives it more fluidity
Carbohydrates - recognition, signalling
Why does diffusion occur?
Because of Brownian Motion (random movement of particles)
Describe the three types of passive transport.
Diffusion - movement of substances from high concentration to low concentration across a semipermeable membrane
Osmosis - diffusion of water
Facilitated Diffusion - diffusion of large/polar molecules across a semipermeable membrane with the use of transmembrane proteins
How do passive and active transport differ?
Passive transport does not require energy because it’s movement of particles with/down the concentration gradient (from high to low concentration)
Active transport does require energy because it’s movement of particles against the concentration gradient (from low concentration to high concentration)
Lipids are composed of
A glycerol backbone and fatty acid chains (long chains of carbon and hydrogen)
