Studied by 40 people
Independent Variable
stand-alone variable that is modified or changed in an experiment.
Dependent
the one that is measured and tested in an experiment and is NOT controlled, but rather, a direct result of the independent variable.
Inferences
Logical explanation based on evidence
Observations
Made using the senses
Credibility of Science acronym
CRAMP
Currency
Is the information presented in the study out of date?
Relevance
Is the research written at a scholarly level?
Author
Who is the author?
Accuracy
Does the information align with the other information on the topic?
Methodolgy
Is there a large enough sample size? Is there a control group? Multiple trials? Has it been published in a peer-reviewed scientific journal?
Purpose
Is the research trying to sell you something? Is there biased language?
Theory
Scientific explanation for patterns or events in nature that is supported by multiple lines of evidence and hypotheses that have been tested repeatedly. It is widely accepted, open to change, and can be used to make predictions.
Laws
Are generalizations and dervied from scientific facts that describe how the natural world bahaves under certain conditions.
Cell Theory
1) All organisms are composed of one of more cells
2) The cell is the basic unit of life for all living things
3) All cells are produced by the division of pre-existing cells
Theory of Spontaneous Generation
Explains that living things (such as maggots) come from non-living things (such as trash). Disproven by swan-neck.
What did Pasteur prove
Living things come from other living things
Polar Molecules
Have positive and negative charges and cause an unequal sharing of electrons between two molecules
Nonpolar Molecules
Have neutral charges and cause an equal sharing of electrons between two molecules
Structure of water
Polar molecule (two poles). Soluable, solvent. Form hydrogen bonds by joining nefativly charged oxygen to positive. High heat capacity, cohesive, and adhesive. Three states of matter.
Density of Water
As water freezes hydrogren expands and being more dense. Ice float on water.
How does water’s polarity influence its properties as a solvent?
it will be able to blend and mix with any ionic or polar substance. This is because a polar molecule has two oppositely charged poles, which both attracts the opposite poles of another, different molecule.
Adhesion
The attraction between different molecules
Cohesion
The attraction between similar molecules
Capillary Action
Adhesion overcomes cohesion.
Surface Tension
Property that allows water to resist an external force. Water’s hydrogen bonds generate its high surface tension.
High Specific Heat
Makes it resistant to temperature change, allowing life forms to maintain relively constant internal temperatures.
Monomer
Building block of a large molecule
Polymer
Long strand of monomers
Carbohydrate
monosaccharide/polymer. (C,H,O) Main source of energy in cells.
Lipid
glycerol and fatty acids/polymer. (C,H,O) Store energy
Protein
amino acid/polymer. (C,H,O,N) Longer-lasting energy source, fights infections, speed up the rate of chemical reactions
Nucleic Acids
(C,H,O,N,P) Capture and transfer ATP, and store and trandmit genetic information
Enzymes
Protiens that speed up reactions by lowering acrivation energy. Reusable and specific.
Similarities between light and electron microscopes
Both have two types that can produce 2D or 3D images when viewing speciments.
Differences between light and electron microscopes
light microscopes use visible light and one or more lenses, while electron microscopes shine a beam of electrons at the specimen. Only light microscopes can view living organisms, but electron microscopes have higher resolution and magnification.
Transmitting Electron Microscopes (TEM)
Produce 2D images of internal structures and has the highest magnification
Scanning Electron Microscope (SEM)
Produce 3D images of surface features
Prokaryotic Cells
Organisms whose cells lack a nucleus and other organelles.
Eukaryotic Cells
Any cell or organism that possesses a clearly defined nucleus
Strucutes of a typical Eukaryotic cell
1) Vacuole
2) Mitochondria
3) Lysome
4) Nucleus
5) Cell Membrane
6) Golgi Apparatus
7) Ribosome
8) Smooth Endoplasmic Retuculum
9) Rough Endoplasmic Retuculum
10) Cytoplasm
11) Neceolus
12) Centriole
13) Chlorplast
14) Cell Wall
15) Microfilaments
16) Microtubles
17) Cytoskeleton
Similarities betwen plant and animal cells
mitochondria, lysosome, nucleus, membrane, Golg apparatus, ribosome, smooth ER, rough ER, cytoplasm, nucleolus
Differences betwen plant and animal cells
Plant cells only have chloroplasts, cell wall, large central vacuole
Protiens (cell membrane)
Form channels and pumps that help to move materials, help move or change shape
Carbohydrates (cell membrane)
allows individual cells to identify one another
Chloresterol (cell membrane)
Helps with fluidity and and acts as a buffer
Osmosis
The movement of water molecules across a selectively permeable membrane from an area of low solute concentration to an area of high solute concentration.
Diffusion
when substances flow from a high concentration to a low concentration until equilibrium is reached.
Facilitated Diffusion
diffusion using special protein channels and carrier proteins to assist in the transport of large, charged molecules or ions across the membrane.
Active Transport
the movement of ions or molecules across a cell membrane into a region of higher concentration, assisted by enzymes and requiring energy (ATP)
Homeostasis
maintained by regulation and by the exchange of materials and energy with its surroundings.
Selective Permeability
The ability of the cell membrane to control the flow of substances in and out of the cell
4 main functions of cell membrane
Phospholipids, carbohydrates, protein channels, cholesterol
Hypertonic
Water moves out
Hypotonic
Water moves in
Isotonic
No net movement
Adenosine triphosphate ATP
is a nucleic acid that stores and releases energy in its bonds when the cell needs it; removing a phosphate group (P) releases energy for chemical reactions to occur in the cell and ATP becomes ADP (adenosine diphosphate). When the cell has energy, the energy is stored in the bond when the phosphate group is added to the ADP.
Photosynthesis
6H20+6CO2 àC6H1206+6O2
(water + carbon dioxide) → (glucose + oxygen)
Reactants Products
Cellular Respiration
C6H12O6 + 6O2 → 6CO2+ 6H20 + ATP
(glucose + oxygen) → (water + carbon dioxide + ATP)
Reactants Products
Fermentation
when cells are not provided with oxygen in a timely manner; this process continues producing ATP until oxygen is available again; glucose is broken down as a source of energy.
Lactic Acid Fermentation
(muscle cells) Glucose → Lactic Acid + 2ATP
Alcoholic Fermentation Glucose à CO2 + Alcohol + 2ATP
Cellular Respiration (def)
Occurs in all living cells, food broken down, energy from glucose released, carbon dioxide given off, oxygen taken in, does not require light.
Photosynthesis
food synthesized (made), energy from the Sun stored in glucose, carbon dioxide taken in, oxygen given off, requires light, occurs in organisms called autotrophs (producers)
Dermal
the protective outer covering of plants
Vascular
the tissue that supports the plant body and transports water and nutrients; xylem and phloem
Ground
the tissue that produces and stores sugars, and support
Roots
absorb and store water and nutrients from soil Root hair increases surface area, root hair cells are always dividing (mitosis).
Stems
transports water, sugar, and minerals; provide support and connection, produces leaves, branches, and flowers. Cambium – a layer of actively dividing cells between the xylem and the phloem, responsible for leaf and stem growth
Leaves
photosynthesis, transpiration, light absorption, and gas exchange.
Flowers
reproductive organs that attract pollinators. Made of 4 specialized leaves; sepals, petals, stamens, and carpels. Sepals protect the flower while its developing, while the bright color of the petals to attract pollinators to the flower.
Fruit
the fertilized ovary of a flower; a structure that encloses and protects a seed.
Seed
A plant embryo
Sexual Reproduction in plants
When the pollen from an anther is transferred to the stigma.
Self-Fertilization
occurs when the pollen from an anther fertilizes the eggs on the same flower.
Cross-fertilization
occurs when the pollen is transferred to the stigma of another plant.
Asexual Reproduction
occurs through budding, fragmentation, vegetative propagation, and spore formation. No flowers are required for this method. Chromosome number is maintained reproduction. The offspring is genetically identical to its parent.
Cones
Reproductive structure of conifers
Xylem
Transports water and minerals upwards the plant from roots to leaves
Phloem
Transports foods and nutrients throughout the entire plant
Meristems
Responsible for plant growth
Why are cells small?
Larger size comes with more demands
Interphase has 4 parts:
G0 resting phase
G1 Growth and normal functions
S DNA replication
G2 organelle replication
Chromosome
a segment of DNA that becomes visible during Prophase.
Chromatin
A highly organized condensed structure made up of DNA, RNA, and proteins that forms the chromosomes in the nucleus of a cell.
Sister Chromatids
two full-length DNA molecules joined together at the centromere, formed during DNA Replication
Homologous Chromosomes
chromosome pairs, one from each parent, that are similar in length, gene position and centromere location. Line up during meiosis.
Centromere
region where the cell’s spindle fibers attach to a chromosome.
Mitosis
1) Prophase
2) Metaphase
3) Anaphase
4) Telophase
Prophase
Nuclear membrane disappears, spindle fibers begin to form, chromatid pairs are visible
Metaphase
Chromatid pairs line up in the middle, fibers attatch
Anaphase
Spindle fibers pull chromosomes apart to opposite ends
Telophase
Spindle fibers disintegrate, chromosomes uncoils and two nuclear membranes form.
Cytokinesis
the division of a cell at the end of mitosis or meiosis, which separates into two daughter cells (mitosis and meiosis 1) or 4 daughter cells (meiosis 2)
Cancer relate to cell cycle
Uncontrolled cell growth, caused by mutations in the genes that control the cell cycle.
Stages if Meiosis
1) Phrophase 1
2) Metaphase 1
3) Anaphase 1
4) Telophase 1
5) Phophase 2
6) Metaphase 2
7) Anaphase 2
8) Telophase 2
Basic Structure of DNA
two linked strands that wind around each other to resemble a twisted ladder — a shape known as a double helix
Why DNA Replication is Semiconservative
The old strand is conserved or saved and used as a template to create a new complementary strand. Make a complementary strand for the following DNA sequence:
ACGTAAGCT
Why is the genetic code is universal
All known organisms have the same four nucleotide bases (adenine, cytosine, guanine and thymine) but are different due to different arrangements of these nucleotide bases.
Role of messenger RNA
Carry instructions for polypeptide synthesis from the nucleus to the ribosomes in the cytoplasm
The of ribosomal RNA
Assemble proteins by linking amino acids together
Role of transfer RNA
Carry amino acids to the ribosomes and match them to the coded RNA message
Note
Flashcard