Semester 1 Study Guide Flashcards
What is an isotope
Atoms of the same element that differ in the number of neutrons they contain
What are the three subatomic particles of an atom
Protons, neutrons, and electrons
What are the two main types of chemical bonds
Ionic bonds and covalent bonds
Difference between cohesion and adhesion
Cohesion- an attraction between molecules with the same substance
Adhesion- an attraction between molecules with a different substance
Why are water me clues polar
They are both positive and negative
Why are water molecules attracted to each other
Because they are polar
What does pH measure?
The concentration if hydrogen ions in a solution
4 major classifications if macromolecules
Lipids-insulation
Carbohydrates- provides immediate energy
Proteins- provide structure
Nucleic acid- stores genetic information
What is polymerization
Molecules composed of many monomers (macromolecules)
What is activation energy?
Energy needed to start a reaction.
What is a catalyst and how does it work
It is a substance that speeds up a chemical reaction by lowering the activation energy
What factors influence enzyme activity?
A rise or decline in pH or in temperature
What are biotic and abiotic factors?
Biotic factors are living while abiotic factors are not
What are the seven layers of the biosphere
Individual Species Population Community Ecosystem Biome Biosphere
What is a primary producer?
An organism that makes it’s own food (an autotroph)
What are consumers?
Organisms that must feed off of other organisms (heterotrophs)
What are the six different types of heterotrophs?
Herbivores-eat only plants Carnivores-eat only animals Omnivores- eat plants and animals Detritivores- feed on dead matter Decomposers- break down organic matter Scavengers- feed in refuse
What’s the difference between a food web and a food chain?
A food chain is a series if steps in which organism transfer energy while a food web is a network of interactions formed by energy exchange among organisms
Identify three types of ecological pyramids
Pyramids of energy, pyramids of biomass, and pyramids of numbers
What is the ten percent rule?
Every time the energy moves up a level, only 1/10 of the original amount is used and stores?
What are the three nutrient cycles?
The carbon cycle, the nitrogen cycle, and the phosphorus
What do autotrophs do during photosynthesis?
Turn sunlight into chemical energy
What is a limiting nutrient?
A limiting nutrient is a substance that is scarce or slowly cycling out of an ecosystem.
What is a niche?
A full range of physical and biological conditions in which an organism lives and the way in which the organism used those conditions
Describe the role that competition plays in shaping communities?
It shapes communities because species compete for space and recourses and usually one wins and lives in the space
What is a keystone species
A singular species that has experienced a change in population
What is symbiosis? Name and describe 3 major types
Symbiosis is any relationship in which two species live closely together
Mutualism- both species benefit
Parasitism- one organism lives on or inside the other and harms it
Commensalism- one organism is helped and the other harmed
What is a pioneer species
The first species to colonize barren areas
Describe the three water zones in an aquatic system
Photic zone- 200 meters, sun lit region, nest surface
Aphotic zone- dark region below photic zone
Benthic zone- the dark areas on the bottom of lakes, streams, and oceans
What is an estuary and why are they so important?
It’s a special kind of wet land formed where a river meets the sea. They’re important because they serve as a spawning and nursery ground for many important fish and shellfish species
What factors affect population growth?
Geographic range, density and distribution, growth rate, and age structure
What’s the difference between exponential growth and logistic growth?
Exponential growth is when the larger a population gets the faster it grows(j shaped curve)
Logistic growth is whe a populations growth slows and then stops followed by a period of exponential growth (s shaped curve)
What is carrying capacity?
The maximum number of an individual species that an environment can support
List three density dependent factors
Competition, predation, and parasitism
How has human population changed over time?
It’s increased dramatically
What are age structure diagram and how are they useful in predicting future population?
They are graphs that show the distribution of various ages in a population. They’re useful because they allow scientists to determine if the number of individuals likely to have children will increase in the future and tell us whether a population is growing, steady, or declining in number
What is cell theory?
The theory that
1 cells make up all living things
2 cells can only come from other cells
3 cells are the building blocks of life
What are the characteristics of prokaryotes and eukaryotes?
Prokaryotes- simple, no nucleus, DNA in cytoplasm, earlier form
Eukaryotes- complex, store DNA in nucleus, later form
What structures do plants have that animals don’t?
Cell wall and chloroplast
What does it mean the a cell membrane is a lipid bilayer?
Because is us composed of two layers of fat cells
Why are cell membranes described as a mosaic of different membranes?
It is made up if many different macromolecules. Lipids carbohydrates and proteins
How do you determine concentration
You divide the mass of the solute by the volume of the solvent
Define solute, solvent, and solution
Solute: substance that is dissolved in a liquid
Solvent: the dissolving substance in a solution
Solution: type of mixture in which all components are evenly distributed
What is equilibrium? Are molecules moving or not moving when equilibrium is reached?
Equilibrium is when the concentration is the same on both sides of the cell wall. It does not mean the cells stop moving
Define isotonic, hypertonic, and hypotonic solutions
Isotonic solution- the concentration is equal inside the cell and the solution
Hypertonic solution- the solution is more concentration
Hypotonic- the solution is less concentrated
What is the difference between phagocytosis and pinocytosis
Phagocytosis- when a cell consumes something for energy
Pinocytosis- when a cell gets energy from the water around it
What is cell specialization?
When specific cells are assigned certain jobs
What are the four levels of organization in multicellular organisms?
Cell, tissue, organ, organ system
What is science and what is it’s goal?
Science is an exploration of the natural world with a goal is figuring out how things work and interact with each other
What is the difference between an observation and an inference?
Observations- made with five senses, used to make a conclusion about a situation
Inference- applying experience to come to a new understanding about a situation
How do scientists develop a hypothesis
Based on prior knowledge and observations
What is a controlled experiment?
An experiment where only on variable is changed or altered at a time
What steps are used to design a good experiment?
Record all conditions so tests can be repeated and replicated, variables are all tested at one time
What is a theory?
An explanation of a situation that is supported with a lot of evidence and data
What are the characterizations of living things
Made of cells Reproduce Have DNA Take in materials for energy Maintain homeostasis Respond to stimuli Grow Evolve and change over time
What is homeostasis
The maintenance of a stable internal environment
What is the difference between sexual and asexual reproduction?
Sexual- each parent donates gametes to form an individual that is a blend of both parents
Asexual- one cell reproduces into 2 identical cells
What measurement to scientists use the most?
Metric system Temperature- Celsius Mass- grams Length - meters Time- seconds Volume- liters or mililiters
