Part 2
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Stahl EOC Review 1 Part 2 * Pictures were taken from a variety of websites by other people. GeneticsThe father of genetics is Gregor Mendel and his pea plants! Mendel’s Law of Heredity: a. Law of Dominance- the dominant allele will prevent the recessive allele from being expressed. b. Law of Segregation- gene pairs separate when gametes (sex cells) are formed. Each gamete has only one allele of each gene pair. c. Law of Independent Assortment- different pairs of genes separate independently of each other when gametes are formed. Homologous Chromosomes= two chromosomes, one from mom and one from dad, that have the same length and general appearance. Trait- characteristic an individual receives from its parents. Gene- carries instructions responsible for gene expression of traits; one comes from each parent in the form of alleles. Homozygous- two alleles of a pair are identical. (BB or bb). Heterozygous- two alleles of a pair are different. (Bb) Dominant- the stronger allele. Always the capitalized allele. Recessive- The weaker, hidden allele. Always lowercase. Genotype- genetic make-up (always the alleles / letters). Phenotype- physical make-up (description like freckles). Monohybrid- cross involving one trait. Ex- Tt X TT Dihybrid- Cross involving two traits. Ex- TtWW X TTww Punnett Square- shows the probable results of genetic crosses. Pedigree- maps genetic traits between generations. Mutations Change in genetic code Stahl EOC Review 2 Part 2 Transmitted to offspring if occurs in sex cells Gene mutation- change in a single gene Chromosome mutation- change in many genes Can be spontaneous or caused by environmental mutagens Sources of Variation: a. Crossing over- genes from chromosomes are exchanged with genes from another chromosome. Prophase of Meiosis. b. Nondisjunction- during meiosis homologous chromosomes do not separate. Results in half of the sex cells having an extra chromosome and the other half having one less. If fertilization occurs with an abnormal sex cell, zygote formed will have either one extra (trisomy) which would be three chromosomes, or one less (monosomy). Example of trisomy = Down syndrome, monosomy = sickle cell anemia. Monohybrid- cross involves one trait. Example- RR X Rr R R R RR RR Always put the capital letter first! Genotype= 2 RR, 2 Rr r Rr Rr Phenotype- all round How do I set up a Punnett Square? Step 1- The first set of alleles to the left of the “X” goes along the top of the square. Step 2- The second set of alleles to the right of the “X” goes along the side of the square. Remember only one letter per box! Step 3- Start crossing them. Stahl EOC Review 3 Part 2 Dihybrid Cross Ex) A tall green pea plant (TTGG) is crossed with a short white pea plant (ttgg). TT or Tt = tall tt = short GG or Gg = green TG TG TG tg TtGg TtGg TtGg TtGg tg TtGg TtGg TtGg TtGg tg TtGg TtGg TtGg TtGg tg TtGg TtGg TtGg TtGg gg = white TG 16 Tall/Green : 0 Tall/White : 0 Short/Green : 0 Short/ White Incomplete Dominance- intermediate / blended phenotype. Example- snap dragons-> Red X White = pink flowers. Codominance-both parental phenotypes show up in offspring. Example- chickens-> Black X White-> black and white feathered chickens. Multiple Alleles- trait with 3+ alleles. Type of codominance Ex- blood types- A, B, O (Ia, Ib, and i). Both Ia and Ib result from a protein called an antigen, on the surface of red blood cells. Allele i is recessive and does not result in an antigen. Stahl EOC Review 4 Part 2 Polygenic inheritance-traits that are produced by two or more genes. Ex.- human skin color, eye color Albinism- there is a gene that blocks the color-> albino. Aneuploidy- condition caused by having abnormal chromosome number. Ex- Down syndrome, also known as trisomy 21. Sex Linked Genes carried on sex chromosomes, specifically the X chromosomes. Ex- Hemophilia and colorblindness. Always use the X chromosome, therefore the actual gene that codes for hemophilia will be represented by a subscript H (normal) or h (carrier) Ex- A normal man marries a woman who is a carrier for hemophilia, predict their offspring. XⱧ XⱧ XH XH Normal daughter Y XH Y Normal son 100 % of the females are normal. 50% of the males are normal Xh XH Xh Daughter is normal but is a carrier. Xh Y This son is a hemophiliac 50% of the males are hemophiliacs. *** because the male has the normal blood clotting allele he will have a H by his X chromosome because he is normal and they are only on X chromosomes. The female is normal but she is a carrier that mean she will have one allele= h on one of her X chromosomes. **** Stahl EOC Review 5 Part 2 Biotechnology: DNA Extraction- the opening of cells to separate / isolate DNA from other cell parts. DNA fingerprinting Human Genome Project Transferring DNA from one organism to another. Sequencing DNA Separating DNA through gel electrophoresis. Pedigree Charts * Chart of genetic history of a family over several generations. * = female = male * Not filled in = Normal * Married Couple= Offspring * If the individual is infected with a disease etc. then the square or circle will be filled in. * If the individual is a carrier then the square or circle will be half filled. * Autosomal pedigree- there is about a 50 / 50 split between males and females. * Sex linked- if most males are affected. * Dominant- one parent must have it. * Recessive- neither parent has it. Stahl EOC Review 6 Part 2 Evolution Father of evolution = Charles Darwin Evolution= species and populations change over time. Natural selection = “ survival of the fittest” Organisms that are best suited to the environment survive and pass genetic traits on to offspring Adaptation- organisms with the most suited traits will survive. Conditions required for Natural Selection: More organisms are born than can survive= Overproduction of offspring Organisms vary in their characteristics, even within a species= Inherited variation Differences in reproduction and survival are due to variation among organisms. If all four of these conditions occur, which they commonly do in both natural and humaninfluenced ecological systems, then natural selection will occur. If any of these is not true, then natural selection cannot occur. Scientists: there were many naturalists before Darwin that discovered evolution- Darwin just built upon them. Carolus Linnaeus- Organized plants, animals, and minerals based upon their similarities into a detailed classification system. Still used today: o Kingdom Good way to remember taxonomy o Phylum and the order is the phrase” King o Class Phillip Came Over From Greater o Order Spain” o Family o Genus o Species- the most distinctive group because he found that they were a group of organisms so similar to one another that they can reproduce and have fertile offspring. o Example of genus, species= Homo sapiens (Homo= genus) and (sapiens= species). * Georges Buffon- proposed that species shared ancestors instead of arising separately. Stahl EOC Review 7 Part 2 * Erasmus Darwin- Charles Darwin’s grandfather, Proposed that all living things were descended from a common ancestor and evolved through mechanisms like competition. * Jean Batiste Lamarck- changed in the environment caused an organisms behavior to change, leading to greater use and disuse of structures or organs. Evidence of Evolution: Fossils- can be found in rocks, ice, amber, etc; they are arranged in order of their age (usually strata = layers in rocks) where the older fossils will be found the deeper you go. They are then aged and placed in the geological time scale. Allows us to compare anatomical characteristics that are shared by different ancestors. DNA- gene or protein sequences from organisms are arranged; species that are related based on fossil evidence are more similar than species thought to be distant relatives one the DNA is analyzed. Embryology- embryos of different vertebrates look alike in earlier stages. You cannot tell the difference between the larvae of a fish and a crab- they look the same. Geography- Organisms on different islands looked similar; therefore they had migrated and went through anatomical changes based on the climate, food, etc. o Example= Galapagos Finches. Homologous Structures- features that are similar in structure but appear in different organisms and have different functions. Ex- the hand of a human, the wing of a bat, and the flipper of a dolphin -> several similar bones, but different functions. Different in detail but similar in structure. Stahl EOC Review 8 Part 2 o Analogous Chromosomes- structures that perform the same function, but are not similar in origin. Ex- wings on a bat and wings on a bird. o Vestigial Structures- structures that have lost their function. Ex- appendix and hip bones in whales. Microevolution Evolution that occurs within the species level; results from genetic variation and natural selection within a population. Ex- antibiotic resistance Ex- pesticide resistance Macroevolution Evolution that occurs between different species; focuses on how groups of organisms change. Convergent evolution- two species evolve similarly, but are in different areas. Divergent evolution- a group of species evolve differently. Adaptive Radiation- a group of species adapt separately to environments’. Ex- Darwin’s finches Speciation- formation of a new species. Geographic isolation- physical barrier that divides a population, results in individuals that cannot mate, leads to a new species. Reproductive isolation- genetic mutation or behavioral change that prevents mating. Stahl EOC Review 9 Part 2 Genetic variation within populations: Increases the chance that some individuals will survive. The greater variation in phenotypes the more likely it is that some individuals can survive in a changing environment. Example- short round penguins might be able to stay warm more easily, but if there is a shortage on food, taller penguins might be able to dive better and catch more fish. Stored in an organisms gene pool = combined alleles of all of the individuals in a population- differences are caused from organisms mating and having offspring. Comes from two main sources: Mutations and recombination o Mutations- random change in the DNA of a gene and this can cause a new allele to form. Ex- frogs going from green to brown for a survival advantage. o Recombination- alleles get shuffled around resulting in different genetic combinations. Classification Taxonomy- the process of biology that studies the grouping and naming of organisms. Aristotle proposed the two groups, plants and animals-> based on whether or not the organisms had blood or no blood. Early 1700’s= Carl Linnaeus and his classification was based on physical characteristics. o 2 kingdoms o Developed genus and species (Homo sapiens)-> Homo= genus, sapiens= species o Naming system is called binomial nomenclature- which means two names. The genus is always capitalized and the species is always lowercase- both italicized. written in italics -1st word is Capitalized –Genus -2nd word is lowercase —species Levels of Classification: Kingdom Phylum Class Order Family Genus Species A way to remember the order is by using the phrase “King Phillip Came Over From Greater Spain” Stahl EOC Review 10 Part 2 Example: Humans Kingdom- Animalia (because we are animals and multicellular) Phylum- Chordata (characterized by a dorsal hollow nerve cord, notochord, pharyngeal gill slits) Class- Mammalia (We are mammals!!!! Give birth to live young, endothermic, and we have mammary glands) Order- Primates (nails, clavicle, orbits encircled with bone, enlarged cerebrum, opposable digits- thumb, it can turn backwards). Family- Homidae (bipedal- walk straight up on two feet, advanced tool use Genus- Homo (Human like) Species- sapiens (of relating to) 6 Kingdoms: - Archaebacteria - Eubacteria -Protista -Fungi -Plantae -Animalia Stahl EOC Review 11 Part 2 Kingdom Characteristics Monera Protista Archaebacteria and Eubacteria -Bacteria -Protists -Prokaryote -Eukaryote -Unicellular -Unicellular -Aerobic / -Aerobic, anaerobic anaerobic -Decomposers -Pathogenic / -Heterotrophic parasitic -Photosynthetic - Animal-like -Chemosynthetic (protozoa) -Pathogenic -Plant-like -Medicinal (algae) -Classified by - Medicinal, food shape: coccus are source spherical, - Mobile bacillus are rod- - move through a shaped , and pseudofoot, spirillum are flagella, and spiral contractile -Binary Fission vacuoles -Vaccines, Ex- amoeba antibiotics -Move by Flagella and Cilia Some Examples of Protists! Fungi Plantae - Eukaryote - Multicellular - Aerobic - Decomposer - Lack Chlorophyll - Pathogenic -Saprophytic- eat dead stuff / parasitic - Medicinal / food source - Heterotrophic - Sexual / asexual - Alternation of Generations -Symbiotic relationships with algae Ex- mushrooms - Eukaryote - Multicellular - Aerobic - Producer - Photosynthesis - Cell Wall (cellulose) - Vascular and nonvascular systems - seeds or cones (angiosperms or gymnosperms) - Poisonous - Medicinal, food source - Alternation of generations - Roots, stems, leaves - Pollination (fertilization) - Germination - Ex- Oak Animalia - Eukaryote - multicellular - Aerobic - Consumer - Cellular Respiration - Invertebrates - vertebrates - Symmetry Ex- Humans Disease Protist Vector (carrier) Symptoms Details Amebic dysentery Ameba histolytica water diarrhea can get from tap water in some places Giardaisis (beaver fever) Giardia water diarrhea, vomiting don't drink water from streams African Sleeping Sickness Trypanosoma Tse tse fly uncontrolled sleepiness, confusion Only found in isolated areas lives in blood Plasmodium Anopheles mosquito fever, chills, death can be treated with quinine lives in blood results in millions deaths per year Toxoplasma cats fetal death or brain damage pregnant women should avoid cat litter Malaria Toxoplasmosis Stahl EOC Review 12 Part 2 Body Symmetry of Animalia: 1. Radial Symmetry-Animals (such as coral and jelly fish) have body parts organized about a central axis and tend to be cylindrical in shape. 2. Bilateral Symmetry-(such as humans and fish) has only a single plane of symmetry that produces mirror halves. 3. Asymmetrical- (sponges) have no general body plan or axis of symmetry that divides the body into mirror-image halves Some Phyla of Animals 1. Porifera – simplest animals: sponges 2. Cnidaria – have stinging cells: jellyfish, sea anemones, corals 3. Platyhelminthes – flatworms: planaria, flukes, tapeworms 4. Nematoda – roundworms: nematodes 5. Mollusca - soft bodies: snails, octopus 6. Annelida - segmented worms: earthworms, leeches 7. Echinodermata – spiny skinned, radially symmetrical: starfish, sea Cucumbers, sand dollars 8. Arthropods – exoskeleton: arachnids, crustaceans, centipedes, insects 9. Chordata - have nerve chords: vertebrates like fish, birds, and mammals Ecology ADAPTIVE RESPONSES: Mimicry – structural adaptation that allows one species to resemble another species; may provide protection from predators Camouflage – structural adaptation that enables species to blend with their surroundings; allows a species to avoid detection Migration – instinctive seasonal movements of animals from place to place Emigration – movement of individuals from a population; leaving the population Immigration – movement of individuals into a population Hibernation – state of reduced metabolism occurring in animals that sleep during parts of cold winter months; an animal’s temperature drops, oxygen consumption decreases, and breathing rate declines Estivation – state of reduced metabolism that occurs in animals living in conditions of intense heat Stahl EOC Review 13 Part 2 Mating / Reproduction – production of offspring for the survival of the species; can be seasonally scheduled ANIMAL BEHAVIOR ADAPTATIONS: Behavior – animal’s response to a stimulus Innate behavior – instinct; influenced by genes Ex: bird defending its nest Learned behavior – changed by experience Ex: training a pet to respond to a specific name Social behavior – interactions between members of the same species Ex: mating and caring for offspring Territorial behavior – organisms defend an area to keep out other organisms (ex: animal marking trees) http://envirosci.net/111/trophic.htm STRUCTURE OF AN ECOSYSTEM Organism >>>>> Species >>>>> Population >>>>> Community >>>>> Ecosystem >>>>> Environment Species – group of organisms that can interbreed Population – units of single species Community – groups of interacting populations Ecosystem – groups of interacting communities Habitat – place where an organism lives Niche – organism’s role within its habitat Stahl EOC Review 14 Part 2 Food Chains: Series of steps representing who is eating who. http://heightstechnology.edublogs.org/tag/foodchain/ Food Webs: Remember the arrows go in the direction in which the energy is flowing. This shows a complex interaction of a variety of organisms. http://www.dunkirkcsd.org/site/Default.aspx?PageID=1416 Stahl EOC Review 15 Part 2 ECOLOGICAL PYRAMID: - Representation of energy transfer Pyramid of Energy – each level represents energy available at that level, 90% decline Pyramid of Biomass – each level represents amount level above needs to consume. 10% is transferred to each level through heat and energy. Pyramid of Numbers – each level represents number of organisms consumed by level above it http://www.docstoc.com/docs/124467477/Ecological-Pyramids Stahl EOC Review 16 Part 2 Website unknown for the cycles. CYCLES: (Matter cannot be created nor destroyed, but can be converted/recycled to other forms) Water Cycle – water is recycled through evaporation, condensation, precipitation, runoff, groundwater, aquifers, respiration, transpiration, excretion, decomposition Nitrogen Cycle – producers take in nitrogen compounds in soil and pass to consumers that consume the producers; decomposers (bacteria) break down nitrogen compounds and release nitrogen gas to air or usable nitrogen so the soil. Carbon Cycle – carbon is recycled through respiration, photosynthesis, fuel combustion, decomposition; carbon can be atmospheric or dissolved, or can be found in organic compounds within the body. Stahl EOC Review 17 Part 2 Reproduction= Fertilization- joining of a sperm and egg cell. Testes – makes and stores sperm via meiosis. The testes are also responsible for produces testosterone, the male hormone. Sperm-male sex cells. Scrotum- Pouch that encloses the testes. Penis- organ where sperm leaves the body. Urethra- where urine leaves. Seminal Vesicle and Prostate Gland- release liquids into the vas deferens when sperm is moving through it. Testosterone is responsible for many of the "male" characteristics. http://www.nationwidechildrens.org/body-system-reproductive-male Epididymis – Where the sperm matures until it’s expelled or reabsorbed. Vas deferens - tube where sperm travels to the outside of the body. Bulbourethral gland / Cowper’s gland- adds fluid to the semen during ejaculation. Semen- a mixture of fluids that looks milky white. * 2 important functions- nourishes, produces, and protects the egg cells. Vagina-birth canal, tube that leads from an opening outside the body. Uterus- strong, thick, muscular walls that holds and nourishes the growing embryo. Cervix- opening of the uterus at the top of the vagina, stretches during birth. http://biologyataglance.wikispaces.com/Cells+and+life+processes Fallopian Tubes- connects the ovary to the uterus. The tubes where the eggs travel down. Ovaries- produce, store, and releases eggs. Eggs-female reproductive cells. Ovum- egg cell. Stahl EOC Review 18 Part 2 http://www.healthac.org/female.html * Estrogen is the hormone responsible for secondary sex characteristics. * Progesterone is the hormone responsible for initiating menstruation. * Testosterone is the hormone that initiates sperm production and male secondary sex characteristics. * Fertilization produces a new cell= zygote. 23 chromosomes from mom and 23 from dad= complete set! * An egg is usually a few days old before it implants in the uterus. At this point, it has already divided several times and is called a blastula. Stahl EOC Review 19 Part 2 * The period from fertilization to birth = gestation. If the zygote has the incorrect number of chromosomes, it may never start growing. An extra chromosome #21 will result in the baby having Down syndrome. First Trimester Second Trimester Up to 3 months Zygote divides several times to form a hollow ball called a blastocyst. Embryo is implanted into the uterine wall – takes about 8-9 days. Nourishment begins. Gastrula forms-> make up the germ layers-> which develop into different structures. Month 3 to 6 Fetus starts to move. By the end it has fully developed eyes. Lungs are starting to develop. Third Trimester 6 months- end Brain develops rapidly. Regular breathing Lungs aren’t fully developed until the 36th week. Stahl EOC Review 20 Part 2 Ectoderm-= outer layer-> forms skin, nerves, and sense organs. Mesoderm=middle layer-> forms bones, muscles, and tissues. Endoderm= inner layer-> digestive system and lungs. All three layers developing in different ways is called differentiation. After 8 weeks the major organs have begun to develop and then it is called a fetus The Brain http://www.snider.fwcs.k12.in.us/apbiology/homework/Unit%2015/chapter_48. htm Stahl EOC Review 21 Part 2 http://www.stroke-survivors.co.uk/About http://www.cea1.com/anatomy-sistems/inner-brain-diagram/ Stahl EOC Review 22 Part 2 Cerebellum- 2nd largest part of the brain. Controls basic movement, balance, and posture. 3 Major Parts of the Brain Brain Stem- smallest part of the brain. Connects the cerebrum to the cerebellum and the spinal cord. Crucial because it control involuntary responses- things that happen automatically like breathing. Cerebrum- the largest part of the brain. Corpus Callosum- large bundle of nerve fibers that connect the left and right cerebral hemispheres. Looks like a “C” on its side. Medulla Oblongata- lowest section of the brainstem. Controls automatic functions including heartbeat, breathing, etc. Pituitary Gland- gland attached to the base of the brain (between the pons and the corpus callosum) that secretes hormones. Pons- connects the hemispheres of the cerebellum and connects the cerebrum with the cerebellum. Thalamus-regulator of sensory information and motor information. Also controls sleep and awake states of consciousness. Hypothalamus-produces hormones that control: body temperature, hunger, moods, release of hormones from many glands, especially the pituitary gland, sex drive, sleep, and thirst. Cerebral cortex- outer layer of the cerebrum. Interprets information from your sensory organs and generates a response. Frontal Lobe- personality, reasoning, and judgment. Voluntary movement and speech. Parietal Lobe- Sensory cortex that interprets and coordinates information regarding the sense of touch. Occipital- Visual information is processed. Temporal- Speech interpretation and hearing. Memory as well. Stahl EOC Review 23 Part 2 https://www.nwpublichealth.org/archives/s2007/adolescent-brain MAJOR SYSTEMS AND ORGANS SYSTEM FUNCTION BASIC ORGANS, AND STRUCTURAL PARTS Circulatory Transports nutrients, fluids, gases Heart, veins, arteries Digestive Breaks down food into essential nutrients Mouth, esophagus, stomach, intestines Endocrine Controls body functions through hormones Glands which secrete hormones Excretory Removes cellular wastes from the blood Bladder, kidneys, urethra Immune Protects the body against invading organisms White blood cells Integumentary Protects the body by forming the body’s outer layer Skin, hair, nails Muscular Moves the body with the help of the skeletal system Muscles Skeletal Supports the body internally Bones, cartilage, ligaments, tendons Nervous Coordinates sensory input with motor output Brain, spinal cord, sense organs Reproductive Provides a means of producing offspring Testes (male), ovaries and uterus (female) Respiratory Controls the exchange of gases Nose, pharynx, larynx, trachea, bronchi, lungs Stahl EOC Review 24 Part 2 DISEASE CAUSING MICROORGANISMS: - Microorganisms are living organisms, usually unicellular bacteria, than can only be seen with a microscope. - Benefits of microorganisms: help us to digest food, encourage normal development of the immune system, fight off bad organisms - Microbes (or pathogens) include viruses, bacteria, fungi, and parasites, which cause disease when our immune system can’t fight them - Microorganisms can be identified based on their size, shape, color, ability to form colonies, etc. - Process of growing the organism is called a culture, and can be used to test sensitivity of organisms to various antibiotics which will help a doctor determine which drug to use in treating an infection. - An infectious disease in humans occurs when balance is disturbed by: exposure to an organism, normal microorganisms in the body become pathogenic, or the human immune system does not act fast enough or strong enough. - Most common areas on the body for microorganisms: skin, mouth, upper airway, intestine, genitals EXAMPLES OF INFECTIOUS ORGANISMS: - Bacteria – microscopic, single celled Streptococcus pyogenes (strep throat) Escherichia coli (urinary tract or intestinal infection) - Viruses – cannot reproduce on its own (invades a host cell) Varicella zoster (chicken pox) Rhinovirus (common cold) - Fungi – yeasts, molds, mushrooms Candida albicans (yeast infection) Tinea pedis (athlete’s foot) - Parasites – organism such as a worm or single celled animal (protozoan) that survive by living inside another organism (host) Stahl EOC Review 25 Part 2 Enterobius vermicularis (pinworm) Plasmodium falciparum (malaria) DEFENSES AGAINST INFECTION: First Line of Immune Defense: - Physical Barriers - skin, mucous membranes (linings of the mouth, nose, eyelids), airways, stomach acid, pancreatic enzymes, bile, intestinal secretions, urinary secretions Second Line of Immune Defense: - Blood – increasing the number of certain types of white blood cells that engulf and destroy invading microorganisms - Inflammation – release or substances from damaged tissue isolates area to attack and kill invaders and dispose of dead and damaged tissue, and to begin repair; blood supply increases which brings more white blood cells to swollen area - Fever – body temperature increases to enhance defense ability (controlled by hypothalamus in brain); causes shivers, chills, body aches; normal body temperature is 98.6ºF, a fever is considered higher then 100ºF. Third Line of Immune Defense: - Immune Response – immune system responds by producing substances that attack invaders (ex: killer T cells, phagocytes) and the immune system produces antibodies that attach to and immobilize the invader to kill it; antibodies will “remember” the infectious organism so it will kill it upon next exposure; immune system is present all over the body and tightly bound to blood and lymph systems; tissues and cells that provide antibodies include red bone marrow, thymus, spleen, circulating lymphatic system, and white blood cells. - There are two types of immunity: - Natural Immunity – created by body’s natural physical barriers or in the form of antibodies passed from mother to child - Acquired Immunity – created by exposure to a specific microorganism, which is “remembered” by the body’s immune system - Immunization – body’s ability to fight off certain organisms is stimulated or enhanced 1. Active Immunization – contain either noninfectious fragments or whole pieces of bacteria or viruses that have been weakened so they will not cause infection but will instead cause the production of antibodies (vaccination) 2. Passive Immunization – antibodies against a specific infectious organism are given directly to the person (vaccine may not be available) External Defenses: - Antibiotics – organic substances synthesized by microorganisms or at a lab used to treat infectious diseases or to prevent them; each antibiotic is specific to a certain bacteria; can be administered by mouth, vein, or muscle - Hygiene – keeping a clean environment that limits exposure to infected bodily fluids, decomposing material, or infected people will prevent the spread of infection Stahl EOC Review 26 Part 2 The Heart- information taken from Holt McDougal text and PowerPoint’s. 30.3 The Heart and Circulation • The heart has four chambers: two atria, two ventricles. • Valves in each chamber prevent backflow of blood. pulmonary valve aortic valve left atrium right atrium mitral valve left ventricle tricuspid right ventricle septum • Muscles squeeze the chambers in a powerful pumping action. 30.3 The Heart and Circulation • Blood flows through the heart in a specific pathway. 1 3 2 4 1. The right atrium receives oxygen-poor blood from the body and pumps it to the right ventricle. 2. The right ventricle pumps blood to the pulmonary artery. This artery, which goes to the lungs, is the only artery in the body that carries oxygen –poor blood. The blood enters the lungs, where carbon dioxide and water vapor diffuse into the alveoli and oxygen diffuses into the blood. 3. Oxygen rich blood returns to the heart through the pulmonary vein and enters the left atrium. This is the only vein in the body that carries oxygen-rich blood. As the atria contract, blood is pumped into the left ventricle, the largest chamber of the heart. 4. When the ventricles contract, blood is pumped from the left ventricle into a large artery, the aorta, and is circulated to the rest of the body. Stahl EOC Review 27 Part 2 30.3 The Heart and Circulation The heart pumps blood through two main pathways. • Pulmonary circulation occurs between the heart and the lungs. – oxygen-poor blood enters lungs – excess carbon dioxide and water expelled – blood picks up oxygen – oxygen-rich blood returns to heart 30.3 The Heart and Circulation • Systemic circulation occurs between the heart and the rest of the body. – oxygen-rich blood goes to organs, extremities – oxygen-poor blood returns to heart • The two pathways help maintain a stable body temperature. Stahl EOC Review 28 Part 2 Immune System- fights infection and pathogens Skin= 1st line of defense, however you have holes where things can enter-> eyes, ears, nose, mouth, and excretory organs-> therefore it needs EXTRA protection! Mucous membranes= hair like cilia that are covered with sticky liquid to trap pathogens. Once a pathogen gets in, the immune system relies on the circulatory system to send chemical signals to coordinate an attack to send specialized cells to the infection site. White Blood Cells * Some material is from PowerPoint presentations taken from Holt McDougal resources. Stahl EOC Review 29 Part 2 Three types of proteins fight off invading pathogens: 1. Complement proteins weaken pathogen membranes. 2. Antibodies make pathogens ineffective. 3. Interferons prevent viruses from infecting healthy cells. Pathogens enter the body-> Basophils (in the blood stream) or Mast cells (in the tissues) release chemical signals-> The signals attract other WBC’s to the infection site-> if the pathogen is a parasite the eosinophils come and spray the parasite with poison-> If the pathogen is a virus, bacteria, or fungus the neutrophils and macrophages (phagocytes) go to work and destroy the pathogens by destroying them-> after phagocytosis the lymphocytes come in and finish the job. Lymphocytes: 1. T-cells= destroy infected body cells. 2. B-cells= produce proteins that inactivate pathogens that have not yet infected a body cell. Proteins: fight off invading pathogens 1. Complement proteinsa. Weaken the cell membrane of pathogens causing water to enter and then it blows up! b. Attract phagocytes to infected area. c. Cause microbes to stick to blood vessel walls where they are easily found and destroyed. 2. Antibodiesa. Proteins made by B-cells b. Bind to pathogens membrane-> inactive c. Make them clump together-> easier to destroy d. Activate complement proteins that weaken pathogen cell membrane. 3. Interferonsa. Produced by body cells that are infected by a virus b. Release enzymes that prevent viruses from entering and infecting c. Inflammation response (nonspecific). Ex- scrape your arm-> it swells up because that is your bodies way of keeping pathogens out. Specific- occurs on the cellular level and is different for each pathogen Antigens Nonspecific- Happens the same way to each pathogen Inflammation Fever Stahl EOC Review 30 Part 2 Inflammation- mast cells or basophils release histamines (chemicals) which cause blood vessel walls to spread out-> fluids move out of the blood vessel into the tissues-> WBC’s squeeze out of the capillary (tiny blood vessels between the larger ones) and move to the area of infection. Once the WBC’s are out of the circulatory system the WBC’s go to work. When pathogens lose the swelling goes down and tissue repair begins. Fever- Mast cells and macrophages release chemicals that cause the hypothalamus to increase body temperature. When your temperature is 103 the hypothalamus cannot regulate the temperature and your enzymes stop working-> leads to seizures, brain damage, and death. Antigens- proteins markers on the surface of cells and viruses that help the immune system identify a foreign cell or virus. Memory cells- specialized B and T cells that remember (immunity) an antigen that invaded your body before-> destroyed but it makes you sick.
