Semester Exam Flashcards
Homeostasis
Maintaining a stable internal environment.
The work of scientists begins with…
careful observations
Controlled Experiment
One variable is changed at a time.
How does science differ from other disciplines?
Can be tested and proved. Science relies strictly on facts.
When is a hypothesis useful?
When it is testable.
Where may a hypothesis come from?
Prior knowledge, observations, etc.
Spontaneous Generation
The idea that life could arise from nonliving matter.
What is not a goal of science or how science works?
Something that can’t be proven.
Inference
Logical interpretation of data based on prior knowledge.
Why do scientists need to publish the details of important work?
So their work can be replicated and further tested.
What is a tissue composed of?
individual or similar cells
Theory
well-supported hypothesis
Osmosis
Diffusion of water through a selectively-permeable membrane like the cell membrane.
Biology
study of life
Ribosomes
Small particles of RNA and protein found throughout the cytoplasm. Proteins are assembled here.
Chromosomes
Thread-like structures contain the genetic information that is passed from one generation of the cells to the next. Characteristics of the cell. Found in the nucleus.
Cell Wall
Strong layer around the cell membrane that protects the cell.
Cell Membrane
The gatekeeper to the cell. Thin, flexible membrane that surrounds the cell.
Characteristics of living things are?
Made of cells, grow and develop, based on universal genetic code, obtain materials and energy, reproduce, respond to their environment, and maintain a stable internal environment.
Nucleus
Brain of the cell. (control center) Found in the center.
Metabolism
Chemical reaction within an organism in which materials build up and break down.
Goal of Science
Investigate and understand the natural world, to explain events in the natural world, and to use those explanations to make useful predictions.
Microscope
Tool that magnifies images that are too small to be seen with the unaided eye.
Compound light microscope
Microscope that allows light to pass through the specimen and uses two lenses to form an image.
Mitochondria
Power house of the cell. Where the cell gets it’s energy from. “Powerhouse”
Chloroplast
Works with the mitochondria to provide the cell energy.
Cell Culture
Group of cells that develop from a single original cell.
Cell Fractionation
Technique used to separate the different cell parts.
Golgi Apparatus
Makes proteins using coded instructions from the nucleus. Then, the proteins are stored, packaged, and shipped like a factory.
Lysosome
“Cleanup Crew” Remove waists and unwanted materials.
Three particles that make up an atom and their charge and where they are found
Proton- positive, center of nucleus
Neutron- neutral, center of nucleus
Electron- negative, orbit nucleus
function of cytoskeleton
gives the cell its shape
Finding protons, neutrons, and electrons
Atomic number is same as protons & electrons; subtract atomic mass number from atomic number to find neutrons; always round up
Democritus thought about cells
cannot be divided
What doesn’t have a cell wall
animal cell
Difference between prokaryotes and eukaryotes
Eukaryotes have a nucleus, prokaryotes do not
Isotopes
different number of neutrons
5 levels of organization
Species, population, community, biome, and biosphere
Species
similar organisms that can breed and produce offspring
Population
group of individuals of the same species that live in the same area
Community
all the populations that live together in a defined area
Biome
group of ecosystems that have the same climate in similar dominant communities
Biosphere
contains the combined portions of the planet in which all of life exist including land, water, and air
Anton van Leeuwenhoek
First person to use a microscope to study nature.
Robert Hooke
Discovered cells by looking at a cork and comparing it to tiny chambers that resembled a monastery.
Covalent and Ionic Bonds
Covalent- share electrons between atoms
Ionic- transfer electrons between atoms
Autotrophs & Heterotrophs
Autotroph(producer)- make own food
Heterotroph(consumer)- rely on other organisms for food
Food Chain & Food Web
Food Chain- series of steps in an ecosystem where organisms transfer energy by eating other organisms - 10% is transferred to the next level; the rest is lost as heat
Food Web- all of the food chains in an ecosystem
Two ways water enters the atmosphere in the water cycle
Evaporation and transpiration
