Final Review Flashcards
What is science and what is its goal?
Science is an organized way of gathering and analyzing evidence about the natural world. An investigation of the world around us.
What is the difference between observation and inference?
An observation is the act of noticing and describing events- made by using the five senses- seeing, smelling, hearing, tasting, and touching
An inference is a logical interpretation based on what scientists already know- often based off observations
How do scientists develop a hypothesis?
They use their observations and inferences to form a hypothesis.
What is a controlled experiment?
An experiment in which only one variable is changed.
What steps are used to design a good experiment?
observing and asking questions
inferring and forming a hypothesis
designing controlled experiments
What is a theory?
a well-tested explanation that unifies a broad range of observations and hypotheses, and enables scientists to make accurate predictions about new situations.
List the characteristics of living things
based on a universal code grow and develop respond to their environment reproduce maintain a stable internal environment obtain and use material energy are made up of cells evolve
What is the difference between sexual and asexual reproduction?
Sexual- two parents
Asexual- one parent
What is homeostasis?
relatively constant internal, physical, and chemical conditions that organisms maintain
What measurement system do most scientists use?
The metric system
What are the three subatomic particles of an atom?
Protons, neutrons, electrons
What is an isotope?
an element that has a differing number of neutrons. It has the same number of protons and electrons but has a different mass.
What are the two main types of chemical bonds?
ionic & covalent
What is the difference between adhesion and cohesion.
Cohesion- an attraction of molecules to the same substance
Adhesion- an attraction between molecules of different substances
Why are water molecules polar?
the oxygen takes the hydrogens’ electrons, making an uneven distribution of electrons
Why are water molecules attracted to one another?
They are polar
What does pH measure?
The concentration of H+ ions in a solution
What is polymerization? Which classes of macromolecules are synthesized in this matter?
The process of many monomers attaching to each other to form polymers. Proteins, carbohydrates
What is activation energy?
The energy needed to start a chemical reaction
What is a catalyst and how does it work?
a substance that speeds up the rate of a chemical reaction by lowering the a reaction’s activation energy.
How is the active site of an enzyme and binding of its substrate like a “lock and key”?
The enzyme site is the lock. It needs a specific substrate (the key) to cause it to change shape
What factors influence enzyme activity?
Temperature
pH
Define seven levels of the biosphere and indicate how you fit into each level.
Species- group of similar organisms that can breed and produce fertile offspring
Students
Population- a group of individuals that belong to the same species and life in the same area
Keith
Community- An assemblage of different populations that live together in a defined area
Rockford
Ecosystem- All the organisms that life in a place, together with their physical environment
Illinois
Biome- a group of ecosystems that share similar climates and typical organisms
North America
Biosphere- Our entire planet, with all its organisms and physical environments
Earth
What are biotic and abiotic factors?
Biotic- living or once living things
Abiotic- Non living things
What is a primary producer? What is another name for them?
An organism that uses solar or chemical energy to produce “food”.
What do autotrophs do during photosynthesis?
Uses solar or chemical energy to produce “food” by assembling inorganic compounds into complex organic molecules.
What are consumers? What is another name for them?
Organisms that ingest other organisms as energy.
Heterotrophs
6 different types of heterotrophs? Examples?
Herbivores- plant eaters
Giraffe
Carnivores- meat eaters
Lion
Omnivores- eat both plants and animals
Bear
Detritivores- Feed on detritus particles
Worm
Decomposers- “feed” by chemically breaking down organic matter
Fungi
Scavengers- Consume te caracasses of other animals
Vulture
How does a food chain aim differ from a food web?
A food chain implies that each creature eats only one other organism. A food web is made of many food chains.
What is an ecological pyramid?
A pyramid that shows the relative amount of energy or matter contained within each trophic level in a given food chain/web.
Identify 3 types of ecological pyramids and describe what they show
Energy- the relative amount of energy in each trophic level
Biomass- the relative amount of living organic matter available at each trophic level
Number- relative number of individual organisms at each trophic level
What is the 10% rule? Page 77 of book
Through each trophic level, only 10% of energy from the level before is transferred.
How does water cycle through the biosphere?
water falls to Earth as precipitation
Becomes groundwater or runs into rivers, lakes, or oceans
Water goes through transpiration or evaporation
What are the 3 nutrient cycles discussed in class? Know details
Carbon
Nitrogen
Phosphorus
What is a limiting nutrient? How can such a nutrient be a limiting factor in an ecosystem?
A nutrient whose supply limits productivity.
Nothing can work without this nutrient
What is a niche? How is it different from a habitat?
the role an organism plays in its habitat.
A habitat is the general place where an organism lives, while a niche is a specific role the organism plays.
Describe the role that competition plays in shaping communities.
Species fight over resources
Define competitive exclusion.
The competitive exclusion principle states that no two species can occupy exactly the same nce in exactly the same habitat at exactly the same time. If there were two species in the same niche, one species would eventually become better at competing for limited resources, leaving the other species with nothing.
What is a keystone species?
a single species whose population sometimes changes.
What is symbiosis? Name 3 major types
Symbiosis is any relationship in which two species live closely together.
Mutualism- Positive Positive
Parasitism- Positive Negative
Commensalism- Positive Neutral
What is a pioneer species?
The first species to colonize barren areas.
Describe characteristics of the major land biomes.
Tropical Rain Forest Tropical Dry Forest Tropical Grassland/Savanna/Shrubland low grasses Desert dry low precipitation plants hold water cold at night hot in day Temperate Grassland Temperate Woodland and Shrubland Temperate Forest Northwestern Coniferous Forest Boreal Forest/Taiga Tundra- Temperature: cold Permafrost
Describe the 3 water zones in an aquatic ecosystem
The Photic Zone- The sunlit region near the surface in which photosynthesis can occur. 200 meters
The Aphotic Zone- The region below the photic zone where photosynthesis cannot occur.
The Benthic Zone- The region where benthos, or aquatic organisms that live on or in rocks and sediments on the bottoms of lakes, streams, and oceans, live.
What is an estuary and why are they so important?
the region where a river meets an ocean. They contain mixtures of freshwater and saltwater and are affected by the rise and fall of ocean tides.
They serve as spawning and nursery grounds for many important fish and shellfish.
What factors affect population growth?
Birth rate
Death rate
Immigration
Emigration
Exponential growth
the larger a population gets, the faster it grows. J-shaped curve. One pair gives birth to 3 pairs who each give birth to 3 pairs etc.
Logistic growth
occurs when a population’s growth slows then stops, following a period of exponential growth. S-shaped curve.
What is carrying capacity?
the maximum number of individuals of a particular species that a particular environment can support.
List 3 density dependent factors
Competition
Predation
Stress from overcrowding
What is a density independent factor?
Density-independent factors affect all populations in similar ways, regardless of population size and density.
How has human population changed over time?
The human population has drastically increased over time.
What are age structure diagrams and how are they useful in predicting future population trends?
Diagrams that show population growth by age group
They can help show how steady a growth rate is and predict when the population will double. They tell whether a population is increasing, decreasing, or is stable.
What is cell theory?
The theory that cells make up the fundamental structure of all living organisms.
All cells come from preexisting cells
Cells are the basic unit of life
What are the characteristics of prokaryotes and eukaryotes
Prokaryotes- Contains DNA in cytoplasm (no nucleus), simple, small, first
Eukaryotes- Contains DNA in nucleus, complex, specialized
What structures do all cells have?
Ribosomes, DNA, cell membrane, cytoplasm
What are the main functions of the cell membrane and cell wall?
To support, protect, and shape the cell. (cell membrane regulates what enters and exits the cell)
What does it mean that a cell has a “lipid bilayer”?
Cell membranes are made of lipid bilayers, which give the cell membranes a flexible structure that forms a strong barrier between the cell and its surroundings.
Why are cell membranes described as a mosaic of different molecules?
It is made up of many different molecules (3 of the 4 macromolecules) that all piece together to form the lipid bilayer.
4 major classes of macromolecules
Structure and function
Lipids-
Proteins-
Carbohydrates-
Nucleic Acid -
What structures do plant cells have that animals do not?
Chloroplasts
Cell wall
Solute
Thing being dissolved
Diffusion
the movement of many substances across the cell membrane
Osmosis
Diffusion specified to water
Facilitated diffusion
Aided diffusion (protein channels)
Active transport
the movement of materials against a concentration difference. Uses energy.
Passive process
Does not use energy
What is equilibrium? Do molecules stop moving?
Equilibrium- the point at which the concentration of a substance is equal on both sides of the cell membrane. Movement does not stop when equilibrium is reached.
Solvent
Thing doing dissolving
Solution
Solute dissolved in solvent
Iso, Hypo, Hyper
Isotonic- the same amount of solute on both sides
Hypertonic- More of a solute on one side
Hypotonic- Less of a solute on one side
ALL TERMS ARE COMPARISONS
What is the difference between phagocytosis and pinocytosis?
Phagocytosis- Engulfment of food
Pinocytosis- Engulfment of water
What is cell specialization?
Different cells have different jobs
What are the 4 levels of organization in multicellular organisms? Simple to complex.
Cell
Tissue
Organ
Organ system
