Biology EOC Review

Water Properties

(18.12) Special Properties of Water:
- Polarity: Water is polar due to the unequal sharing of electrons between hydrogen and oxygen atoms.
- Hydrogen Bonding: Bonds between water molecules, leading to surface tension.
- Surface Tension: Caused by hydrogen bonds, allowing small creatures to walk on water.
- Cohesion: Attraction between like molecules (e.g., water molecules sticking to each other).
- Adhesion: Attraction between unlike molecules (e.g., water sticking to other substances).
- Capillarity (Capillary Action): Ability of water to move up thin tubes, aiding plants in water acquisition.
- Ability to Moderate Temperature: Water's high heat capacity stabilizes air and water temperatures by absorbing/releasing heat.
- Expands When Frozen: Water expands upon freezing due to hydrogen bonds, becoming less dense and floating, which insulates aquatic life.
- Solvent of Life: Many substances (e.g., salt, sugar) dissolve in water.

Chemistry and Macromolecules

(18.1/18.11) Macromolecules:
- Four main types: carbohydrates, proteins, nucleic acids, lipids (CHONPS).
- Structure:
  - Polymers are large molecules made of repeating monomer units.
  - Carbohydrates:
    - 1:2:1 ratio of C, H, and O. Ringed structures.
    - Monomer: monosaccharide (e.g., glucose).
    - Disaccharide: two sugar molecules.
    - Polysaccharide (starch): three or more molecules.
  - Proteins:
    - C, H, O, N, and sometimes S.
    - Monomer: amino acids.
  - Nucleic Acids:
    - C, H, O, N, P.
    - Phosphate group, sugar, and a nitrogenous base.
    - Monomer: nucleotides.
  - Lipids:
    - C, H, O (mostly C and H - fatty acids & glycerol).
    - No monomers (not made of repeating units).
- Functions:
  - Carbohydrates:
    - Glucose: immediate energy source.
    - Polysaccharides: starches; cell walls and structural support.
  - Proteins:
    - Structure (cells, hair, nails, muscles, skin).
    - Enzymes: speed up reactions.
    - Transport, hormones, helps fight disease.
  - Enzymes:
    - Catalysts that speed up reactions by lowering activation energy.
    - Factors like concentration, pH, and temperature affect enzyme function.
    - Enzymes exhibit specificity, fitting into substrates like a key into a lock.
    - Enzymes work in optimal conditions.
  - Nucleic Acids:
    - Store/transmit genetic information (DNA & RNA).
  - Lipids:
    - Insulation, protection, energy storage, barriers (plasma membrane).
- Homeostasis: Regulation of internal environment for survival.
- pH: Measure of acidity (0 -
- Stimulus: Anything causing a reaction in an organism.
- Metabolism: All chemical reactions within an organism.

Cell Theory

(14.1/14.4) Cell Theory:
- Scientific Theory: Well-supported explanation; the most powerful explanation scientists offer. Can be overturned.
- Laws: Well-supported descriptions of relationships but don’t explain why.
- Theories do not become laws, nor do laws become theories
- Cell Theory:
  1. The cell is the basic unit of life.
  2. All organisms are made of cells.
  3. Cells come from preexisting cells.
- Theory of Biogenesis: Life comes from life.
- Theory of Spontaneous Generation: Life comes from non-living material (disproved by Frances Redi).
- Scientists like Van Leeuwenhoek, Hooke, Schwann, Schleiden, and Virchow, along with microscopes, aided in the development of cell theory.

Prokaryotic vs Eukaryotic, Plant vs Animal & Cellular Transport

(14.3/14.2) Cell Structures and Transport:
- All cells have: Plasma membrane, ribosomes, cytoplasm, genetic material.
- Chromosomes: Contain genetic material copied and passed on during reproduction.
- Prokaryotic vs. Eukaryotic:
  - Prokaryotic Cells:
    - No membrane-bound organelles.
    - Only in bacteria, unicellular.
  - Eukaryotic Cells:
    - Have membrane-bound organelles (nucleus, lysosomes, mitochondria, Golgi apparatus, ER, vacuoles, chloroplasts).
    - Fungi, protists, plants, animals; unicellular or multicellular.
  - Organelle: Membrane-bound structure with specific functions in eukaryotic cells.
- Prokaryotic Structures: Cell wall, plasma membrane, cytoplasm, plasmid (circular DNA), ribosomes, flagella.
- Eukaryotic Structures: Unicellular or multicellular
- Cellular Organization: Cells, tissues, organs, organ systems, organisms (for multicellular organisms).
  - Cell Wall: Inflexible barrier; support & protection.
  - Plasma Membrane: Selectively permeable barrier.
  - Cytoplasm: Everything inside the plasma membrane.
  - Nucleus: Control center containing DNA.
  - Nuclear Envelope: Membrane enclosing the nucleus.
  - Nucleolus: Makes ribosomes, found in the nucleus.
  - Chromatin: Relaxed form of DNA.
  - Ribosomes: Help make proteins.
  - Endoplasmic Reticulum: Site of protein synthesis.
  - Microtubules/Filaments: Cytoskeleton, involved in movement & shape of cell.
  - Vacuoles: Storage.
  - Mitochondria: Powerhouse, cellular respiration occurs here, makes energy (ATP).
  - Chloroplasts: Made of thylakoids, & chlorophyll pigments, does photosynthesis
  - Golgi Apparatus: Packs & sends proteins.
  - Lysosomes: Breaks down old/harmful substances.
  - Cilia: Hair-like structures for movement & feeding.
  - Flagella: Whip-like tail for movement.

Plant Cell vs Animal Cell:

Plant Cells: Chloroplasts, cell wall, large central vacuole.
Animal Cells: Centrioles, small vacuoles, no cell wall, no chloroplasts.
Both: Plasma membrane, ribosomes, cytoplasm, genetic material, nucleus, mitochondria, Golgi apparatus/body, Endoplasmic Reticulum, chromatin, microtubules/filaments, lysosomes.

Transport in Cells

Plasma Membrane: Selective barrier made of proteins and phospholipids.
Diffusion: Movement from high to low concentration.
Hypotonic: Cell swells.
Hypertonic: Cell shrinks.
Isotonic: Cell stays the same.
Osmosis: Movement of water across a membrane from high to low concentration.
Passive Transport: No energy required, moves with the concentration gradient; includes facilitated diffusion, carrier proteins, and ion channels.
Active Transport: Requires energy, moves against the concentration gradient; includes sodium-potassium (Na-K) pump.

Photosynthesis & Cellular Respiration

(18.9/18.7/18.8/18.10) Relationship Between Photosynthesis and Cellular Respiration:
- Photosynthesis: Organisms use sunlight to make glucose.
 - 1st Stage (Light Dependent): Sun's energy converted into chemical energy (ATP).
 - 2nd Stage (Light Independent/Calvin Cycle): ATP fuels glucose production.
 - Occurs in chloroplasts using pigments like chlorophyll.
 - Photosynthesis: $6CO2 + 6H2O \rightarrow C6H{12}O6 + 6O2$
- Cellular Respiration: Occurs in mitochondria; oxygen & glucose produce energy (ATP).
 - Occurs in every living thing.
 - Aerobic (with O2) and anaerobic (without O2) types.
 - Cellular Respiration: $C6H{12}O6 + 6O2 \rightarrow 6CO2 + 6H2O + ATP$
- Relationship: Products of photosynthesis (glucose & oxygen) are reactants for cellular respiration, and vice versa.
 - Photosynthesis: $6CO2 + 6H2O \rightarrow C6H{12}O6 + 6O2$
 - Reactants: Carbon dioxide + water
 - Products: glucose + oxygen
 - Cellular respiration: $C6H{12}O6 + 6O2 \rightarrow 6CO2 + 6H2O +ATP$
 - Reactants: Glucose + oxygen
 - Products: Carbon dioxide + water + ATP
- ATP: Photosynthesis uses ATP to make glucose, while cell respiration uses glucose to make ATP.
 - Photosynthesis: Sun -> ATP -> Stored in glucose.
 - Cellular Respiration: Glucose -> ATP.
- Photosynthetic Organisms: Plants, algae, seaweed, plankton, photosynthetic bacteria.

Plant Structures and Functions

(14.7) Plant Organs & Tissues:
- Plant Organs:
  - Roots: Absorb water & anchor plant.
  - Stems: Support leaves/flowers.
  - Leaves: Photosynthesis (stoma/stomata, chloroplasts, chlorophyll).
  - Flowers: Reproductive parts (stamen, pistil).
  - Fruits: From ovaries containing eggs which become seeds (plant embryo), and cones.
- Physiological Processes: Photosynthesis, cellular respiration, transpiration, reproduction.
- Plant Tissues:
  - Meristematic: Region of growth.
  - Ground: Makes up most of the plant.
  - Dermal: Epidermis or outer covering of plant.
  - Vascular: Xylem (transports water & minerals up), phloem (transports sugar throughout plant).
- Plant Structures:
  - Cambium (cork or vascular cambium): Meristematic tissue producing new transport cells; cork is outer bark.
  - Guard Cells: Surround the stoma/stomata (pore), regulate opening & closing based on water availability.
  - Stoma/Stomata: Pore for gas exchange (CO2 & O2) and water.

Molecular Genetics

(16.3/16.4/16.5/16.9) DNA Replication, Protein Synthesis:
- Mutation in gamete (sperm/egg) will be passed to offspring, causing phenotypic change.
- Genetic code is universal among organisms, using the same 20 amino acids.
- DNA components (sugar, phosphate group, base) are universal.
- Similarities in genetic codes indicate common ancestry.
- Nucleic Acid: DNA & RNA transmits genetic information.
- Nucleotide: Monomer of nucleic acid (sugar, phosphate group, nitrogenous base).
- Nitrogenous Bases: Adenine = thymine, cytosine = guanine (A=T, C=G).
- DNA Replication: Copying DNA using A-T-C-G; accuracy is essential.
  - Occurs before cell division (mitosis & meiosis) during interphase.
- Protein Synthesis (Gene Expression): Making proteins from DNA in 2 steps:
  1. Transcription: m-RNA copies info from DNA using AUCG (occurs in the nucleus).
  2. Translation: m-RNA brings codon to cytoplasm, t-RNA transfers correct amino acid to ribosome, r-RNA ensures correct order.
- Codon: Three-base code sequence in m-RNA that specifies an amino acid.
- DNA → RNA → Amino Acids → Protein

The Cell Cycle & Mitosis

(16.17/16.8/1614/16.16) Mitosis and Meiosis:
- Chromatin: Relaxed form of DNA.
- Sister Chromatids: Two halves of a doubled chromosome.
- Centromere: Holds sister chromatids together.
- Spindle Fibers: Attach to centrioles, pull apart sister chromatids during anaphase.
- Centrioles: Animal organelle, involved in cell division.
- Haploid: 1(n), one set of chromosomes.
- Diploid: 2(n), two sets of chromosomes.
- Cell Cycle & Mitosis:
  1. Interphase: Preparation & growth, chromosomes doubled (as chromatin).
  2. Mitosis (PMAT):
    - P) Prophase: DNA visible, nuclear envelope disappears, centrioles move.
    - M) Metaphase: Chromosomes in the middle.
    - A) Anaphase: Sister chromatids move apart.
    - T) Telophase: Nuclear envelope reappears, cell pinches in (animals) or forms cell plate (plants).
  3. Cytokinesis: Division of cytoplasm.
- Purpose of Mitosis: Repair, growth, development, asexual reproduction.
  - Forms 2 identical cells.
  - Chromosome number must be maintained.
- Cancer results from mutations affecting enzymes regulating the cell cycle.

Cell Cycle & Meiosis

Cell Cycle & Meiosis:
1. Interphase: preparation & growth, chromosomes doubled, can’t see chromosomes b/c they are in the form of chromatin,
2. Meiosis – PMAT I P1) Prophase I: Homologous chromosomes line up & crossing over occurs, M1) Metaphase I: chromosomes line up in tetrads, A1) Anaphase I: apart, T1) Telophase I: 2 nuclei
  *PMAT 2 P2) Prophase II M2) Metaphase II A2) Anaphase II T2) Telophase II: results in 4 totally different cells each with ½ (haploid) the # of original chromosomes.
3. Cytokinesis: division of the cytoplasm
  *Purpose of Meiosis: to make haploid sex cells or gametes (sperm & egg) or spores. The chromosome number is halved during meiosis.
  Reduction division results in the formation of haploid (n)$ gametes or spores (contain half the number of chromosomes as the original cell).
  *Law of independent assortment: Random distribution of alleles during gamete formation (factors are inherited independently of each other)
  *Homologous chromosomes: pairing of like chromosomes during prophase 1 of meiosis
  Crossing over: Exchange of chromosome segments between homologous chromosomes during prophase I
  Describe the role the role of meiosis in sexual reproduction, including how these processes may contribute to or limit genetic variation.
  *Tetrads: when homologous chromosomes line up next to each other during Metaphase 1 of meiosis

Mendel Genetics & Complex Inheritance

(16.1/16.2) Mendel's Laws:
- Homozygous: 2 of the same alleles (TT or tt).
- Heterozygous: 2 different alleles (Tt).
- Dominant: Trait that is observed.
- Recessive: Trait that is hidden unless in the homozygous condition.
- Phenotype: Physical appearance.
- Genotype: Gene representation using letters.
- Incomplete Dominance: (red + white = pink) Heterozygous phenotype a blend of parents.
- Codominance: (black + white = black spots + white spots) Neither allele is dominant; both are expressed.
- Sex-linked: Mutation on the sex (X) chromosome.
- Polygenic: Many genes influence one phenotype (e.g., eye color, hair color, height).
- Multiple Alleles: More than 2 alleles to choose from (ex: blood type (IA , IB , i)).
 - Type A blood = I^A I^A $or$ I^A i $</li> <li>Type B blood =$ I^B I^B $or$ I^B i $</li> <li>Type AB blood =$ I^A I^B $</li> <li>Type O blood =$ ii$$
Pedigrees:
- = Male
- = female
- Law of Segregation: During gamete formation, 2 alleles for each trait separate.
- Law of Independent Assortment: Random distribution of alleles during gamete formation.
- P Generation: Parental generation (e.g., PP x pp).
- F1 Generation: Offspring of parental generation (e.g., all Pp).
- Crossing two heterozygous traits yields a 3:1 phenotypic ratio and a 1:2:1 genotypic ratio.
- Dihybrid cross of all heterozygous traits yields a 9:3:3:1 phenotypic ratio.
- Inheritance outcomes can be expressed as percentages, ratios, or fractions.
- Punnett squares predict cross outcomes.

Biotechnology

(16.10) Biotechnology Impact:
- Gene coding for spider web proteins placed in goat eggs; goats produce spider web protein in milk for bulletproof vests.
- Impacts individuals, society, and the environment (positive and negative).

Evolution & Natural Selection

(15.13/15.14/15.15) Natural Selection:
- Favored trait depends on environment, enabling survival and reproduction.
- Conditions:
  - Overproduction of offspring
  - Inherited variation
  - Struggle to survive
  - Differential reproductive success
- Genetic Drift: Fluctuations in allele frequencies within a population, leads to evolutionary change.
- Gene Flow: Alleles entering/leaving a population (immigration/emigration), results in evolutionary change.
- Mutations and Genetic Recombination: Increase genetic variation.
- Nonrandom Mating: Mate choice based on characteristics.

Evidence, Evolution, Primate Evolution

(15.1/15.10) Evidence and Trends in Evolution:
- Evidence from fossil record, comparative anatomy, embryology, biogeography, molecular biology, observable change.
- Trends in hominid evolution (6 million years ago to modern humans):
  - Increased brain size
  - Decreased jaw size
  - Language development
  - Tool manufacture
- Bipedalism evolved, brain/skull size increased, jaw/teeth size decreased.
- Adaptive Radiation (Divergent Evolution): Rapid speciation in response to new habitat or opportunity.
- Convergent Evolution: Different species evolve similarly under similar conditions; no recent common ancestor (dolphin & shark).
- Coevolution: Species evolve in close relationship with other species.
- Gradualism: Gradual changes in a species over time.
- Punctuated Equilibrium: Rapid genetic change causes species to diverge quickly, interrupted by long periods of little change.
- Homologous Structure: Anatomically similar structures with different functions; common ancestor (bird wing & reptile limb).
- Analogous Structure: Superficially similar structures with same function; not from a common ancestor (dolphin & shark, beetle & eagle).
- Comparative anatomy and embryology assess similarities (homologous structures, vestigial organs).
- Contributions of Darwin, Lamarck, Lyell, Malthus, Mendel, Wallace in developing the theory of evolution.

Origin of Life

(15.8) Scientific Explanations of Origin of Life:
- Early atmosphere: hydrogen, methane, ammonia, no O2, water vapor.
- Origin of organic molecules - Primordial soup theory - chemicals + uv light or electricity resulted in a variety of organic compounds (carbs lipids AA but not proteins).
- Eukaryotic cells arose from a prokaryotic cell engulfing another prokaryotic cell = endosymbiont theory(endosymbiosis).
- Contributions of Pasteur, Oparin, Miller and Urey, Margulis, Fox in the development of scientific explanations of the origin of life.

Classification, Heredity, Evolution

(15.6/15.4/15.5) Classification of Organisms:
- Classify organisms based on domain and kingdom characteristics.
- Classification changes based on evolutionary relationships.
- Hierarchical classification based on evolutionary relationships.
- Domains:
  - Archaea: Prokaryotic, live in extreme environments, gave rise to eukaryotic cells.
  - Bacteria: Prokaryotic, cyanobacteria (1st photosynthetic cell, produced O2).
  - Eukarya: Eukaryotic; includes kingdoms Animalia, Plantae, Fungi, Protista.
- Kingdoms:
  - Protista: Most diverse; animal-like, plant-like, fungus-like.
  - Fungi: Made of hyphae, heterotrophic decomposers.
  - Plantae: Multicellular, chloroplasts, photosynthesis, autotrophs, specialized tissues.
  - Animalia: Multicellular, heterotrophic, nervous system, centrioles, no chloroplasts, no cell wall.
- Classification: Grouping organisms based on criteria.
  - Morphological characters: similar structures.
  - Biochemical characters: chromosome structures, AA sequence.
  - Bioinformatics: computer database of genes.
  - Evolutionary history
  - Recent common ancestor
- Taxonomy: Identifying, naming, classifying organisms.
- Phylogeny: History of evolutionary relationships.
- Cladograms: Diagram of evolutionary relationships.

Principles of Ecology

Food Webs and Cycling of Matter
(17.9/E.7.1) Food Webs:
- Producers: Autotrophs, produce their own food using sun/chemicals (plants, algae, plankton).
- Consumers: Heterotrophs, eat to get energy (herbivores, carnivores, omnivores, decomposers).
- Autotrophs: Organisms that makes its own food by collecting energy from the sun or chemicals (same as a producer)
- Heterotrophs: Organism that cannot make its own food and must eat to survive: same as a consumer (herbivore, carnivore, omnivore & decomposer ARE ALL HETEROTROPHS BECAUSE THEY EAT)
- Herbivores: Eat only plants.
- Carnivores: Eat only meat.
- Omnivores: Eat both plants and meat.
- Decomposers: Break down dead organisms using enzymes (mushroom).
- Detritivore: Organism that eats fragments of dead matter (earthworm)
- Scavenger: An animal that eats dead carcasses (vulture)
- Predator: Organism that captures and eats another (prey).
- Prey: The organism that is eaten by another
- Symbiosis: Relationship between 2 different organisms: Mutualism ++, commensalism +0, parasitism +-
- Trophic Level: Step in a food chain.
  - Trophic level 1 = producer: autotroph
  - Trophic level 2 = primary consumer: herbivores
  - Trophic level 3 = secondary consumer: omnivores or carnivores
  - Trophic level 4 = tertiary consumer
- Energy Transfer: 90% of energy is lost as heat, only 10% is transferred between trophic levels.
- Movement of matter and energy through biogeochemical cycles (water and carbon).

Principles of Ecology

Water and Carbon cycle
- Water Cycle: Evaporation, Condensation, Percipitation, Transpiration, Run-off
- Carbon Cycle:
  - CO2 enters leaves during photosynthesis.
  - Herbivores eat plants.
  - Consumers eat other consumers.
  - Decomposition; fossil fuel formation; combustion; cell respiration returns CO2 to the atmosphere.

Population Ecology

(17.5/17.2/17.4/17.8) Population Ecology:
- Population size determined by births, deaths, immigration, emigration, limiting factors, carrying capacity.
- Habitat: Physical location of an organism.
- Niche: Unique role of an organism.
- Population: Group of organisms in a place.
- Community: Group of populations in a place.
- Ecosystem: All organisms plus abiotic factors in a place.
- Biome: Group of ecosystems sharing climate and organisms.
  - Desert: Hot, dry
  - Rainforest: most diverse, high rainfall
  - Taiga: Has evergreen trees
  - Deciduous Forest: Has trees that lose their leaves
  - Grassland: grass
  - Savannah: grass, scrubby trees
  - Tundra: permanently frozen ground (permafrost)
- Biosphere: All life on Earth.
- Immigration: Moving into an area.
- Emigration: Moving out of an area.
- Limiting factors: Any abiotic or biotic factor that limits organism distribution, #’s, or reproduction. EX. Abiotic: sunlight, climate, temperature, water, nutrients, fire, soil, space. Biotic: other plants and animals etc.
  - pH, O2, CO2, N2, phosphorus, salinity in aquatic systems.
  - Light, water depth, latitude, temperature, topography, proximity to land.
- Range of Tolerance: Upper and lower limits for survival.
- Density-dependent: limiting factor that depends on the numbers in the population
- Density-independent: limiting factor that doesn’t depend on the population

Ecological Changes and Biodiversity

Seasonal variations, climate change, succession.
- Changes in temp. and weather during summer, spring, fall, winter
- Climate change: global warming & the green-house effect – trapped CO2 gasses cause temperature to rise.
- Primary Succession: No soil (after volcano), pioneer species (lichen, moss) start.
- Secondary Succession: Has soil (after fire).
- Climax Community: Mature community.
- Biodiversity: The number of different species living in a specific area.
- Decreasing biodiversity: Catastrophic events, climate changes, human activities, invasive species.
  - Decreased ecosystem stability & reduction in plants/ animals for food, clothing, energy, medicine and shelter and future because of their (genes) DNA.

Human Impact

(17.20/17.11/17.13) Human Impact on Environmental Systems:
- Renewable Resources: Water, energy, wildlife, forests.
- Non-renewable Resources: Fossil fuels, coal, oil, gas.
- Monitoring environmental parameters when making policy decisions is necessary because there are many possible negative impacts resulting from the use of renewable and/or nonrenewable resources.
- Humans’ actions may negatively impact environmental systems and/or affect sustainability (providing enough resources (food, water etc) to keep something alive

Immune System

(14.52/14.6) Human Immune System:
- Nonspecific Response: Fever, skin, mucous, saliva, tears, phagocytosis, inflammation, redness.
- Specific Immune Response: Antigen causes antibody formation.
- Vaccines: Dead/weakened pathogen that prevents disease.
- Antibiotics: Medicine that kills bacteria.
- Heredity and family history impact personal health.
- Prevention, detection, and treatment strategies.
- Vaccines: Immune system builds antibodies against the pathogen
- Significance of genetic factors, environmental factors, and pathogenic agents to health

Human Reproduction

(16.13) Human Reproduction:
- Male and female reproductive system anatomy/physiology.
- Pregnancy Trimesters:
  - 1st Trimester: organs and tissues begin to develop (fetus).
  - 2nd Trimester: rapid growth & lungs
  - 3rd Trimester: growth, fat accumulates, forming nerve cells, needs protein
- Male Reproductive System:
  - Seminal Vesicle: Sugars for sperm.
  - Prostate Gland: Alkaline solution to neutralize acidity.
  - Vas Deferens: Duct for sperm transport.
  - Urethra: Tube for urine exit.
  - Epididymis: Sperm maturation and storage.
  - Scrotum: Contains testes.
  - Penis: Male sex organ.
  - Testes: Produce sperm.
- Female Reproductive System:
  - Ovaries: Produce eggs.
  - Oviduct (Fallopian Tube): Connects to uterus.
  - Uterus: Baby develops.
  - Cervix: Lower end of uterus.
  - Vagina: Female sex organ.
- Human Development:
  - Placenta: Delivers nutrients, removes waste.
  - Umbilical Cord: Connects fetus, has blood vessels.
  - Amniotic Sac: Protects and cushions embryo with fluid.
  - Fertilization: sperm & egg (zygote),
  - Implantation: blastocyst attaches to the Endometrium lining of the uterus
  - Zygote fertilized egg.
  - Morula: solid ball of cells, after the zygote undergoes mitosis.
  - Blastocyst hollow ball of cells,.
  - Gastrulation 3 germ layers formed
  - Neurulation develops into the nervous system by the end of the 1st trimester, major organs have developed from the 3 germ layers.
  - Hormones are involved in secondary sex characteristics which appear during puberty, hormones stimulate egg and sperm production, & control the menstrual cycle

Cardiovascular System

(14.36) Cardiovascular System:
- Blood pressure: force of blood against artery walls.
- Blood Volume: amount of blood circulating
- Resistance: opposing or preventing blood flow
- Disease: blood clots, heart disease, high blood pressure, arteriosclerosis (plaque buildup).
- Exercise
- Decrease in diameter of vessel = Decrease in blood flow & Increase in blood pressure.
- Increase in diameter of vessel = Increase in blood flow & Decrease in blood pressure.
- Exercise dilates (increases) diameter of blood vessels = Increase in blood flow

The Brain

(14.26) The Brain:
- Parts of the human brain:
  - Cerebrum
    - Frontal lobe
    - Parietal lobe
    - Occipital lobe
    - Temporal lobe
  - Cerebellum
  - Brain stem
    - Pons
    - Medulla oblongata

Scientific Thinking & Scientific Method

(N.1.1) Scientific Thinking & Scientific Method:
- Scientific inferences from observations.
- Scientific Method: Independent variable, Dependent variable, Control group, Experimental group
- Microscopes:
  - Compound microscope: glass lenses, light source to magnify
  - Dissecting microscope similar to compound microscope but used for to magnify larger structures.
  - Transmission electron microscope uses magnets to pass electrons through a specimen.
  - Scanning electron microscope – electrons pass over the surface of a specimen.