Semester Exam Flashcards
What is homeostasis?
A process by which organisms maintain a stable internal environment.
What does the work of science begin with?
Careful observation.
What is a controlled experiment?
Changing a single variable in an experiment.
How does science vary from other disciplines?
Science relies strictly on facts or things that can be proven.
When is a hypothesis useful?
When it is testable.
Where may a hypothesis come from?
Observation, prior knowledge, logical inferences, imagination
What is spontaneous generation?
Life arising from nonliving matter
What is not a goal of science?
Something that can’t be proven
What is an inference?
Logical interpretation based on prior knowledge.
Why do scientists need to publish the details of important work?
So other scientists can replicate their experiments and see if they got the same results, further test them
A tissue is made of what?
Individual or similar cells
What is a theory?
A well-supported hypotheseis
What is osmosis?
The diffusion of water through a selectively permeable membrane
What is biology?
The study of living things
What are ribosomes?
Small particles in the cell on which proteins are assembled; made of RNA and protein.
What are chromosomes?
Threadlike structures in the nucleus that contain genetic information passed from one generation to the next.
What is a cell wall?
A strong layer around the cell membrane that protects the cell.
What is a cell membrane?
A thin, flexible barrier around the cell that regulates what enters and leaves the cell.
What are the characteristics of living things?
- grow and develop
- reproduce
- are based on a universal genetic code.
- obtain energy and materials.
- respond to their surrounding environment.
- obtain stable internal conditions
- change over time.
What makes up the nucleus of an atom?
Protons and neutrons
Where is the nucleus of a cell? What does it do?
The center of the cell; it is the “control center” and controls the rest of the cell
What is metabolism?
Building up and breaking down materials.
What is a microscope?
A tool that magnifies things that are too small to be seen with the unaided eye.
What is a compound light microscope?
A microscope that allows light to pass through a specimen and uses two lenses to form an image.
What is a mitochondria?
The powerhouse of a cell that gives it energy.
What is a chloroplast?
Organelle that works with the mitochondrion to give the cell energy.
What is cell fractionation?
A technique used to separate different parts of a cell.
What is a Golgi apparatus?
Organelle that makes proteins using coded instructions from the nucleus.
What is a lysosome?
“Cleanup crew”; remove waste and unwanted materials from the cell.
What are the three particles that make up an atom?
Protons, neutrons, and electrons
What charge does a proton have?
Positive
What charge does a neutron have?
Neutral
What charge does an electron have?
Negative
Where are protons found in an atom?
The nucleus
Where are neutrons found in the atom?
The nucleus
Where are electrons found in the atom?
Orbiting the nucleus
What is the function of the cytoskeleton?
Gives the cell its shape
What is the function of the cell wall?
Supporting and protecting the cell
What did Democritus believe about atoms?
Atoms cannot be divided
How do you find the number of protons, neutrons, and electrons?
Atomic number = the number of protons and elctrons. Atomic mass - atomic number are neutrons.
What doesn’t have a cell wall?
Animal cells
What are the differences between prokaryotes and eukaryotes?
Prokaryotes have no nucleus, eukaryotes do.
What are isotopes?
Atoms that have different numbers of neutrons
What is a species?
Similar organisms that can reproduce.
What is a population?
A group of individuals of the same species that live in the same area.
What is a community?
The assemblage of all the populations living in an area.
What is a biome?
A group of ecosystems that have the same climate and other similar dominant communities.
What is a biosphere?
The combined portions of the planet in which all of life exists including land, water, and air.
Who is Anton van Leeuwenhoek?
The first person to see living organisms in pond water through a microscope
Who is Robert Hooke?
Discovered cells by looking at a cork and compared them to tiny chambers in a monastery
What is the difference between a covalent and an ionic bond?
Covalent bond shares electrons between atoms while ionic bonds transfer the electrons.
What is the difference between autotrophs and heterotrophs?
Autotrophs (producers) make their own food, while heterotrophs (consumers) rely on other organisms for food.
What is a food chain?
A series of steps in an ecosystem where organisms transfer energy by eating other organisms and being eaten - 10% of the energy is transfered to the next level and the rest is lost as heat.
What is the water cycle?
Water enters the atmosphere through evaporation and transpiration
What is the goal of science?
To investigate and understand the natural world, to explain events in the natural world, and to use those explanations to make useful predictions.
