First Nine Weeks Test Flashcards
What is not the goal of science
something you can’t prove
What are the steps in an experiment
Purpose, research, hypothesis, experiment, and conclusion
What is a hypothesis
A scientific or educated guess
What is a controlled experiment
When only one variable is changed at a time and all other variables remain the same
Why do scientists publish their experiments
So other scientists can look at and test their experiments
Wha is a theory
When a hypothesis becomes so well supported
What is biology
The study of living things
What are five characteristics of all living things
All living things are made up of a basic unit called cells, reproduce, grow and develop, obtain and use materials and energy, and respond to their environment
What is homeostasis
When an organism maintains a stable internal condition
What is metabolism
Combination of chemical reactions through which an organism builds up or breaks down materials as it carries out life’s processes
What are all the microscopes
TEMs, SEMs, compound light microscope, and a regular microscope
What is cell culture
When a group of cells develops from a single cell
What is cell fractionation
Separates different parts of the cell
What is the goal of science
To investigate and understand the natural world
Describe TEMs
Shines a beam of electrons through a thin specimen
Describe SEMs
Produces a realistic three dimensional image of the surface of objects
Describe compound light microscopes
Allow light to pass through the specimen and use two lenses to form an image
Describe regular microscopes
Produces magnified images of structures that are too small to see with the unaided eye
What is an inference
A logical interpretation based on prior knowledge or experience
What is cell
A collection of living matter enclosed by a barrier that separates it from its surroundings
What is data
Information gathered from observations
Describe redis experiment
He tried to prove spontaneous generation and looked for maggots on covered and uncovered meat
What is spontaneous generation
The idea that life could arise from nonliving matter
What is the responding variable
responds to the manipulated variable
What is the manipulating variable
The variable that is deliberately changed
Why is it important to test only one variable at a time
So you can figure out exactly which variable is causing the change
3 particles that make up an atom
Protons, neutrons, and electrons
Where are they located
Protons and neutrons are in the nucleus and electrons orbit around the nucleus
What are isotopes
Same element different number of neutrons
Why is the basic unit of matter
Atoms
What is an element
Pure substance that consists entirely of one type of atom
What is the metric system
Decimal system of measurements whose units are based on certain physical standard
Why do scientist use the metric system
They need to replicate each other’s experiments and most experiments use measurements
What is the metric system based on multiples of
10
What does atom mean and what is the Greek word for it
Smallest unit of matter; atomos and it means unable to be cut
What are the charge of the three particles
Protons are positive, neutrons are neutral, and electrons are negative
How are covalent bonds formed
When electrons are shared between atoms
How are ionic bonds formed
When one or more electrons are transferred from one atom to another
What are species
Groups of organisms so similar to one another that they can breed and produce fertile offspring
What are populations
Groups of individuals that belong to the same species and live in the same area
What are communities
Assemblages of different populations that live together in a defined area
What are ecosystems
Collections of all organisms that live together in a particular place together with their physical environment
What are biomes
Groups of ecosystems that have the same climate and dominate communities
What is a biosphere
Portions of the planet in which all life exists including land, water, air, and atmosphere
What are herbivores
They only eat plants
What are carnivores
They only eat animals
What are omnivores
Eat both plants and animals
What are detritivores
Eat plant and animal remains and other dead matter
What are decomposers
Break down organic matter
What are autotrophs
Same as producers make their own food
What are heterotrophs
Same as consumers and rely on other organisms for their food
What are food chains
Series of steps in which organisms transfer energy by eating and being eaten
What are food webs
Link all the food chains in an ecosystem together
What are trophic levels
Step in a food chain or food web
What are ecological pyramids
Diagrams that show the relative amount of energy contained within each trophic level
What is biomass
The total amount of living tissue in a trophic level
What happens in photosynthesis
Autotrophs use energy from the sun to make oxygen rich carbohydrates
What is chemosynthesis
When an organism uses chemical energy to produce carbohydrates
How much energy is passed between each trophic level
10%
Where does the energy go
It’s released as heat
What is nitrogen fixation
The process by which bacteria converts nitrogen into ammonia
What is denitrification
The process by which some soil bacteria converts nitrates into nitrogen gas
What is primary productivity
The rate at which organic matter is created by producers
What is a limiting nutrient
When an ecosystem is limited by a single nutrient that is scarce or cycles very slowly
How does a limiting nutrient affect the ecosystem
If a nutrient is in short supply it will limit an organisms growth
What are the levels of organisms within an ecosystem
Species, populations, communities, ecosystems, biomes
