Biology:
Study of living things
Cell:
Basic unit of all forms of life
Properties of life: Homeostasis
-The maintenance of a stable level of internal conditions even though environmental conditions are constantly changing
Levels of Organization: Atom
Basic unit of matter
Levels of Organization: Molecules
Groups of atoms
Levels of Organization: Cells
Basic unit of living things
Levels of Organization: Tissue
Groups of cells that work together to perform a specific function
Levels of Organization: Organ
A collection of tissues that work together
Levels of Organization: Organ System
A collection of organs working together
Levels of Organization: Organism
Collection of organ systems(Individual living thing)
Levels of Organization: Population
Group of similar organisms living in the same place
Levels of Organization: Community
All of the populations in a specific area
Levels of Organization: Ecosystem
The collection of all of the communities and non-living things(air, dirt, and water) in an area
Levels of Organization: Biosphere
Part of earth that contains all ecosystems
Homeostasis
relatively constant internal physical and chemical conditions that organisms maintain
Steps of Scientific Method
Step 1: Ask a question
Step 2: Do background research
Step 3: Construct a hypothesis
Step 4: Test your hypothesis by doing an experiment
Step 5: Analyze the data and draw a conclusion
What is a Hypothesis?
Possible explanation for a set of observations or possible answer to a scientific question, If, Then statement
Variable
Independent: factor in a controlled experiment that is deliberately changed; also called manipulated variable
Dependent: variable that is observed and that changes in response to the independent variable; also called the responding variable
Controlled Experiment
experiment in which only one variable is changed
Factors that would reduce competition within a species
Symbiotic Relationship:
Relationship in which two species live close together
3 Types of Symbiosis: Parasitism
One organism lives off another organism
One Benefits-One is Harmed
3 Types of Symbiosis: Commensalism
When One organism is harmed and the other does NOT benefit nor is harmed
3 Types of Symbiosis: Mutualism
When BOTH organisms benefit
Niche:
full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions
Habitat:
area where an organism lives including the biotic and abiotic factors that affect it
Autotroph:
organism that is able to capture energy from sunlight or chemicals and use it to produce its own food from inorganic compounds; also called a producer
Heterotroph:
organism that obtains food by consuming other living things; also called a consumer
Carnivore:
organism that obtains energy by eating animals
Omnivore:
organism that obtains energy by eating both plants and animals
Decomposer:
organism that breaks down and obtains energy from dead organic matter
Food Chain:
a series of steps in an ecosystem in which organisms transfer energy by eating and being eaten
Food Web:
network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem
Where does all of our food energy ultimately come from?
Sun
Subatomic Particles: Protons
Positively (+) charged particles located in the nucleus of an atom
Subatomic Particles: Neutrons
Neutral(no charge) particles
Subatomic Particles: Electrons
Negatively (-) charged particles that are located and form an electron cloud around the nucleus
Relationship between atomic number, mass number, and numbers of protons, neutrons, and electrons
Atomic Number = Protons
Protons = Electrons
Protons + Neutrons = Mass Number
Mass Number - Protons = Neutrons
Mass Number - Neutrons = Protons
Ionic vs Covalent bonds
Ionic- Electrons are transferred
Covalent- Electrons are shared(Single bond=Sharing of 2 electrons, Double bond=Sharing of 4 electrons, triple bond=Sharing of 6 electrons)
Parts of Cell Theory
The cell is the smallest living unit in all organisms
All living things are made of cells
All cells come from preexisting cells
Difference between Prokaryote and Eukaryote
Prokaryote: No nucleus
Eukaryote: Has Nucleus
Functions of the nucleus
Control center of cell, holds genetic material(DNA), and contains the information needed to make proteins
Mitochondria
Provides most of energy needed for a cell, converts glucose to ATP
Cytoplasm
Is where cell expansion as well as growth and replication are carried out
Also holds Nucleus, Organelles(perform specialized functions), and the Cytoskeleton(gives shape and support, Anchor's organelles, and allows some cells to move)
Chloroplasts
They convert light energy into chemical energy through photosynthesis
Golgi Apparatus
Prepares large molecules for storage in the cell or for secretion out of the cell
Ribosome
Makes proteins out of amino acids
Cell Membrane
Separates the cell's contents from it's environment
Endoplasmic Reticulum(ER)
An extensive network of membranes that produce materials for the cell
With Ribosome attached(Rough ER): Helps synthesize proteins and manufacture new cell membranes
Without Ribosomes attached(Smooth ER): Makes lipids, processes carbohydrates, and modifies chemical toxic to the cell
Differences between plant and animal cells
Plants have a chloroplast, cell wall, and vacuole
Parts of a Solution
Solute: the substance that dissolves in a solvent
Solvent: the substance in which a solute dissolves
Ex: Kool-Aid powder(Solute) is put into water(solvent) and then makes Kool-Aid(Solution)
Process of Diffusion
Movement from an area of high concentration to an area of low concentration; Once the concentrate is evenly distributed, Equilibrium is reached
Process of Osmosis
Movement of water across a semipermeable membrane
Hypertonic: High solute concentration
Hypotonic: Low solute concentration
Isotonic: Equal concentrations of solute
Structure of DNA
"twisted ladder" made of nucleotides
DNA replication
Process by which DNA is replicated
1 step: DNA unzips(Enzymes split apart and unwind the DNA double helix)
2 step: Bases Pair Up(Free nucleotides in the cell find their complementary bases along the new strands with the help of DNA polymerase)
3 step: Backbone bonds(The sugar-phosphate backbone is assembled to complete the DNA strand)
2 new double helixes are formed--1 strand of old and one of new DNA
Write the complementary strand for this DNA strand: C-G, A-T
AGTCGTCGATCGAT
TCAGCAGCTAGCTA
Codon
Three-nucleotide sequence on messenger RNA that codes for a single amino acid
Ex: CUU, CUA, UGA, UAA, UAG
Process of Translation
3 Steps:
Initiation(mRNA attaches to ribosome)
Elongation(lengthening of the amino acid chain(tRNA))
Termination: (ribosome reaches a stop, codon and protein are released)
Process of Protein Synthesis
Transcription: Genetic information from DNA copied to a strand of mRNA. RNA Polymerase unzips DNA and then binds RNA bases to their complementary bases on the DNA strand)
Translation: The code of language located within the nucleic acids is changed into the language of proteins
Compare and Contrast DNA and RNA
DNA RNA
-Double Stranded -Single=Stranded
-Deoxyribose sugar group -Ribose sugar group
-Base Pairs: C-G, A-T -Base Pairs: C-G, A-U
Frame Shift Mutation
The deletion or addition of nucleotides resulting in the disruption of codons
Point Mutation
A change in only one nucleotide; the substitution of one base