Science midterm cards Flashcards
What is an atom?
the building blocks/ the smallest unit of matter
What is a cell?
the building blocks/ the smallest unit of life
What is an element?
a substance made up of only 1 atom, but same number of protons
e.x. Hydrogen
What is a molecule?
A group of two or more same or different atoms bonded together
e.x. O2
What is a compound?
A group of two or more different elements bonded together
e.x. NH3
How are molecules and compounds similar and different?
Similar: all compounds are molecules
different: molecules are 2 or more same atoms chemically combined, compound is 2 or more different atoms chemically combined
Chemical formula for water
H2O
Why is water polar?
Water has two poles: 2 negatively charged electrons into a positively charged proton.
What is surface tension?
Strong cohesive forms in the water molecules
Adhesion
the process of sticking onto different substances
Cohesion
the process of sticking into the same substance
Which element of water pulls more?
Oxygen
If you’re doing a penny lab, why did the water droplets stick on the penny?
Cohesion: The water molecules stick to each other
Adhesion: It sticks onto the penny
What are the 6 key characteristics of life? (does not need to be in order)
- Reproduction
- Response to stimuli
- Maintains homeostasis
4.Metabolism - Can move
- Adapt to environments
What is the cell theory?
- All cells come from preexisting cells
- All cells are the basic unit of life
- All living organisms are made up of cells
Cell wall
- found only in the plant cell
- maintains a rigid structure in the plant
Cell membrane
- found in both cells
- acts like a security guard; in other words, it means it controls what goes in and out of the cell
Cytoplasm
- found in both cells
- the jelly-like substance that holds all the organelles in a place
Nucleus
- found in both cells; but only in eukayortic ones
- acts like the brain; in other words, it is the control center of the cell and holds the DNA in place.
DNA
- found in the nucleus (or floats in the cell if prokayortic)
- the genetic material in which we all have
Mitochondria
- found in both cells
- nicknamed “powerhouse of the cell”; produces energy called ATP to both plant and animal cells.
Endoplasmic Reticulum (ER; rough and smooth)
- both rough and smooth ER are found in both cells
- Rough: produces ribosomes
Smooth: Produces fats called lipids
Golgi apparatus (Golgi body)
- found in both cells
- ships the proteins and lipids produced by the smooth ER and ribosomes
Lysosomes
- found in only the animal cell
- stores waste materials, unlike the vacoule
Ribosomes
- found in both cells
- makes the proteins; the golgi ships them
Chloroplasts
- found in only the plant cell
- produces the green pigment we call chlorophyll
Chlorophyll
- found in only the plant cell (bc it comes from chloroplasts)
- gives the plant its green color
Vacuole
- found in both cells; to be specific (this organelle is larger in the plant cell than the animal cell)
- stores water and waste inside, unlike lysosomes
examples of prokayortes
examples include: bacteria, archaea, etc.
What are the 3 shapes of bacteria?
- bacillus (rod)
- sprillus (spiral)
- coccus (sphere)
Where do archaea live?
volcanoes, geysers, etc.
How do we destroy the bad bacteria?
Taking antibiotics on a regular basis
Bacterial illnesses include
- Strep throat
- Tuberculosis
- Lyme disease
- Tetanus
- E.Coli
etc….
What are the plant-like protists?
euglena
What are the animal-like protists?
- Paramecium
- Amoeba
- Diatoms
How do these 3 protists move
- amoeba
- euglena
- paramecium
Amoeba: False foot called pseudopod
Euglena: their flagellum
paramecium: the movement of their cilla
Why are they protists? They should be eukayortes!
Well, because they both have plant and animal-like characteristics
for instance
- euglena has chloroplasts but doesn’t have a cell wall
Why are spirogyra, onion cells, and skin cells multicellular
they are composed of multiple cells, as seen in a microscope
Why don’t onion cells have chloroplasts?
They are generally grown underground, so photosynthesis isn’t necessary
What are antibiotics?
medicine which helps kill bacteria
What are vaccines?
shots which help you protect from viruses/bacteria
What are antibiotics?
proteins which help stimulate bad bacteria
