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1 2 Jack Bowers’ Chapter 2 Biology Notes Three parts of an atom: electrons, neutrons, and protons. Difference between ionic and covalent bonds: An ionic bond is formed by the attraction between ions (formed by the gain/loss of electrons,) while a covalent bond is formed by the sharing of electrons between atoms. Polar molecule: A molecule with both negatively and positively charged regions. A common example is water. Solute and Solvent: A solvent dissolves a solute and is found in the greater amount, and solutes dissolve in a solvent. Together, they make up a solution. Draw glucose: (C6/H12/O6) A monomer is a molecular subsection, and a polymer is a group of combined monomers. Lipid: Nonpolar molecules that include fats, oils, and cholesterol. High temperature and ‘Ph’ change the structure of enzymes. A catalyst is an enzyme in living things, and its functions are to reduce activation energy and increase chemical reaction duration. A protein is a polymer made up of amino acid monomers. Proteins differ in the order and number of amino acids they contain. Ions are molecules that have become charged, negatively or positively, because of the gain or loss of electrons. A hydrogen bond is an attraction between a hydrogen atom (+) and a negative atom. An acid is a compound t at releases a hydrogen ion (+) when dissolving in water, and increases the concentration of hydrogen ions (+) in a solution. On the other hand, bases are compounds that remove hydrogen ions (+) from a solution. A solution’s acidity is measured by Ph, or its hydrogen ion concentration. When a chemical reaction is sketched, reactants are placed on the left side, and the products are placed on the right side. An exothermic reaction releases more energy than it absorbs, and an endothermic reaction absorbs more energy than it releases. Monosaccharides are simple sugars, and polysaccharides are starches. An unsaturated fat is liquid at room temperature, while a saturated fat is a solid at room temperature. Phospholipid: Has fatty acid ‘tails’ and a polar ‘head’ that contains a phosphate group. 3 Jack Bowers 10.14/15.2008 Biology Chapter 3 Notes Organelles enable eukaryotic cells to carry out specialized functions. Animal cells are eukaryotic Prokaryotic cells do not have organelles Eukaryotic cells have organelles Phospholipids combine to create the double layer that is a cell membrane Ligands are also known as signal molecules The nucleus’ double membrane is known as the nuclear membrane The nucleolus produces RNA and ribosomes RNA is used to make proteins Vesicles are organelles that transport cell materials and are involved in endocytosis and exocytosis Endocytosis is the movement of materials, that are too large for diffusion, into a cell by use of vesicles Proteins and polysaccharides are brought into a cell by endocytosis Exocytosis is the movement of materials, such as waste and other things too large for diffusion, out of a cell by use of vesicles A cell that requires large amounts of energy likely has a large quantity of mitochondria Chloroplasts are organelles involved in the process of photosynthesis Only plants, bacteria, and algae have cell walls Bacteria are prokaryotic cells Passive transport is the movement of molecules across the cell membrane that does not require the use of cell energy Diffusion, a type of passive transport, is the movement of molecules across a cell membrane from higher to lower concentration regions (down the concentration gradient) Diffusion through ion channels is passive transport Facilitated diffusion, a type of diffusion, is diffusion made easier by the use of transport proteins Transport proteins are also known as channel proteins, protein channels, or carrier proteins Osmosis, a type of passive transport and diffusion, is the movement of water across a cell membrane Water does not need a protein channel to cross a cell membrane Active transport is the movement of molecules across a cell membrane, from low to high concentration regions, that requires energy from the cell (against concentration gradient) Most of a cell’s energy is produced by mitochondria Mitochondria and chloroplasts have DNA Plant cell analogy: Shoe Box o The cardboard box is like the cell wall o The plastic bag inside the cardboard box is like the cell membrane Marker proteins, made partially of carbohydrate chains, are located on the outside of the cell and serve as identification tags Receptor proteins are found in the membrane Receptors bind with ligands, also known as signal molecules, and change in shape There are two types of signal molecules: o Intracellular: Inside the cell o Membrane: In the membrane Chemical signals are transmitted across the cell membrane by signal molecules Receptor proteins bond to signal molecules (ligands) outside the cell 4 Chapter 5 Notes – Jack Bowers Mitosis: Process by which a cell divides its nucleus and contents o Body Cells (somatic) are produced o Starts with one cell, ends with two cells o Each cell has 46 chromosomes (23 pairs) o The 46 chromosomes come in pairs called homologous pairs o Each of the two resulting cells has forty-six chromosomes, just like the parent cell o Metaphase: The pair of sister chromatids stack o The sister chromatids split into chromatids in anaphase o Process of mitosis: IPMAT Interphase: Cell continues normal functions Prophase: Chromosomes form and become visible Metaphase: Chromosomes attach to spindle fibers and align along the middle of the cell Anaphase: Nucleus starts to be divided Telophase: The nucleus continues to divide, with a pinch between the two new nuclei becoming visible Cytokinesis: Stage at which two daughter cells are formed In asexual reproduction, Meiosis: Cell division involving gametes o Starts with one cell, and ends in four cells o Each resulting cell has the original 23 chromosome pairs o The sister chromatids stay connected at the centromere in anaphase o Goes through two divisions: one cell – two cells – four cells Anaphase: Third phase of mitosis in which chromatides separate and are pulled to opposite sides of the cell Apoptosis: Programmed cell death Asexual reproduction: Process by which offspring are produced from a single parent; does not involve the joining of gametes Benign: Having no dangerous effect on health, especially referring to abnormal growth of cells that are not cancerous Binary Fission: Asexual reproduction in which a cell divides into two equal parts Cancer: Common name for cell division characterized by uncontrolled cell division. Carcinogen: Substance that improves or promotes the development of cancer Cell cycle: Pattern of growth, DNA replication, and cell division that occurs in a eukaryotic cell Cell differentiation: Process by which unspecialized cells develop into their mature form and function Centromere: Region of condensed chromosomes that looks pinched; where spindle fibers attach during meiosis and mitosis Chromatid: One half of a duplicated chromosome Chromatin: Loose combination of DNA and proteins that is present during interphase Chromosome: Long, continuous strand of DNA that consists of numerous genes and regulatory information Cytokinesis: Process by which cell cytoplasm divides Growth Factor: Broad group of proteins that stimulate cell division Histone: Protein that organizes chromosomes and around which DNA wraps Malignant: Cancerous tumor in which cells break away and spread to other parts of the body; causing harm to the organism’s health Metaphase: Second phase of mitosis when spindle fibers align the chromosomes along the cell equator Metastasize: To spread by transferring a disease – causing agent from the site of disease to other parts of the body Organ: Group of different types of tissue that work together to perform a specific function or related functions Organ system: Two or more organs that work in a coordinated way to carry out similar functions Prophase: First phase of mitosis when chromatin condenses, the nuclear envelope breaks down, the nucleolus disappears, and the centrosomes and centrioles migrate to opposite sides of the cell Stem cell: Cell that can divide for long periods of time while remaining undifferentiated Telomere: Repeating nucleotide at the ends of DNA molecules that do not form genes and help prevent the loss of genes Telophase: Last phase of mitosis when a complete set of identical chromosomes is positioned at each pole of the cell, the nuclear membranes start to form, the chromosomes begin to uncoil, and the spindle fibers disassemble Tissue: Group of cells that work together to perform a similar function Section 5.1 Quiz: o DNA is copied during the Synthesis stage of the cell cycle 5 o ‘Gap 1’ is the longest stage in the cell cycle o Stomach lining cells divide at the highest rate o A cell’s ratio of surface area to volume limits its size o Neurons undergo mitosis least often Section 5.2 Quiz: o A ‘telomere’ is a structure that protects the ends of chromosomes o A chromatin is a loose organization of DNA and proteins o DNA is organized in a cell by wrapping it around histones (proteins) at regular intervals o Metaphase is the stage of mitosis in which spindle fibers attach to chromosomes (and align the chromosomes along the middle of the cell) o Daughter cells have the same number of chromosomes as the original cell Section 5.3 Quiz: o When an oncogene mutates, the cell cycle speeds up (eventually resulting in cancer) o Growth factors are proteins that stimulate cell division o Apoptosis is programmed cell death o Benign and malignant tumors are different in that benign tumors do not spread, while malignant tumors fragment and may spread to other parts of the body o Treatments for cancer include radiation therapy, surgery, and chemotherapy, but not ‘HeLa cells’ Section 5.4 Quiz: o Most prokaryotes reproduce through binary fission o Mitosis differs from binary fission in that mitosis is the division of a cell’s nucleus o Asexual reproduction may be an advantage to an organism that lives in a small, widely scattered population in that the organism would not have to spend time an energy to find a mate o Sexual reproduction involves gametes (sex cells) o Starfish fragments growing into whole new starfish is an example of the reproductive process of fragmentation Section 5.5 Quiz: o Bones, muscles, and kidneys form from the middle layer of a vertebrate embryo o The following are arranged from smallest to largest: cell – tissue – organ – organ system o A cell in an embryo will differentiate based on its location within the embryo o Totipotent stem cells can grow into any cell type in the body o Stem cells cannot turn into any cell type after becoming specialized 6 Jack Bowers 1.8.2009 Biology Chapter 6 Notes Vocabulary/Other Mitosis: Replication of somatic diploid cells. o Creates two diploid cells from one diploid cell. o Chromosomes stay in pairs. o Continues until death. Meiosis: Splitting of diploid cells to create gametes. o Produces four sperm in the male, and one egg in the female. o Chromosomes are split up among resulting gametes. Gametogenesis: Process by which gametes are produced through the combination of meiosis and other maturational changes Polar Body: Haploid cell produced during meiosis. Is in the female of many species; these cells have little more than DNA and eventually disintegrate. Body Cells: o Also known as somatic cells o Are diploid (have two copies of each chromosome,) and have a total of 46 chromosomes arranged in 23 pairs o Have 44 autosomes and 2 sex chromosomes Sex Cells: o Also known as gametes o Are haploid (have one copy of each chromosome,) have a total of 23 single chromosomes o Types: Sperm: Comes from male. Provides DNA for the offspring Egg: Comes from female. Provides DNA, organelles, molecular building blocks, and materials for the offspring Autosomes: Chromosomes that contain genes for characteristics not directly related to the sex of the organism Sex Chromosomes: Sex chromosomes (determine gender in animals: XY = Male, XX = Female) Sexual Reproduction: Process by which two gametes fuse and offspring that are a genetic mixture of both parents are produced Fertilization: Fusion of an egg and sperm cell Mendel: Scientist who studied pea plants and provided the basis of modern genetics Homologous chromosomes: Chromosomes that have the same length, appearance, and copies of genes, although the alleles may differ Crossing Over: Exchange of chromosome segments between homologous chromosomes during meiosis I. Cross: Mating of two organisms Monohybrid Cross: Cross, or mating, between organisms that involves only one pair of contrasting traits Dihybrid Cross: Cross, or mating, between organisms involving two pairs of contrasting traits. Test cross: Cross between an organism with an unknown genotype and an organism with a recessive phenotype Gene: Specific region of DNA that codes for a particular protein Genetics: Study of the heredity patterns and variation of organisms Genetic linkage: Tendency for genes located close together on the same chromosome to be inherited together Genome: All of an organism’s genetic material Genotype: Collection of all an organism’s genetic information that codes for traits Phenotype: Collection of all an organism’s physical characteristics Punnett Square: Model for predicting all possible genotypes resulting from a cross, or mating Heterozygous: Characteristic of having two different alleles that appear at the same locus of sister chromatids. Trait: Characteristic that is inherited Allele: Any of the alternative forms of a gene that occurs on a specific place on a chromosome Dominant Allele: Allele that is expressed when two different alleles are present in an organism’s genotype. Represented in a punnett square by a capital letter Recessive Allele: Allele that is not expressed unless two copies are present in an organism’s genotype. Represented in a punnett square by a lower-case letter Probability: Likelihood that a particular even will happen Purebred: Type of organism whose ancestors are genetically uniform 1. 2. 3. 4. 5. 1. 2. 3. 4. 5. 1. 2. 3. 4. 5. 1. 2. 3. 4. 5. 1. 2. 3. 4. 5. 1. 2. 3. 4. 5. 7 Homozygous: Characteristic of having two of the same alleles at the same locus of sister chromatids. Law of segregation: Mendel’s first law, stating that… o Organisms inherit two copies of genes, one from each parent o Organisms donate only one copy of each gene in their gametes because the genes separate during gamete formation Law of Independent Assortment: Mendel’s second law, stating that allele pairs separate from one another during gamete formation Quizzes: 6.1: Meiosis is the process that produces gametes In the human body, germ cells are found in the ovaries and testes The term ‘autosomes’ describes chromosomes that exist in cells as homologous pairs Gametes are haploid Meiosis results in haploid cells 6.2: Sister chromatids are separated during the ‘anaphase II’ phase of meiosis. Homologous chromosomes are separated during the ‘anaphase I’ phase of meiosis One egg cell forms from a female germ cell Gametogenesis is the production of eggs and sperm Polar bodies are the cells formed by meiosis, in females, that are broken down Section 6.3: When Mendel crossed a purple-flowered plant with a white-flowered plant, all of the offspring had purple flowers. Leaf structure did not play an important role in developing Mendel’s conclusions. The advantage of Mendel’s working with purebred plants was that any variations in offspring had to be caused by the experiment. When Mendel crossed two purple flowered plants from a F1 generation, both purple flowered and white flowered plants appeared in a 3:1 ratio. The fact that homologous chromosomes pair up and then separate during meiosis was not one of Mendel’s conclusions Section 6.4: The term homozygous describes a person who has two identical alleles at a specific locus. A gene and an allele are related in that an allele is an alternative form of a gene. The term ‘phenotype’ describes the physical traits of a person. If all of the offspring of a cross between a purebred tall plant and a purebred short plant, one can infer that the allele for tallness is dominant. The allele rr represents a homozygous recessive genotype Section 6.5: The grid boxes in a Punnett square represent the possible genotypes of offspring from two parents An example of a dihybrid cross is aabb x AaBb In a Bb x bb cross, the predicted offspring would be 50% Bb and 50% bb An example of a test cross is Ff x ff Mendel’s law of independent assortment is “Allele pairs separate independently during meiosis Section 6.6: The event of homologous chromosomes paring up randomly during meiosis I is a cause of genetic variation during Meiosis The number of possible chromosome combinations varies by species because different species have different numbers of chromosomes The term ‘crossing over’ describes the exchange of chromosome segments during prophase I Crossing over occurs in germ cells You can say that two genes that are linked are close together on a chromosome 8 Jack Bowers, Period 6 1.22.2009 Chapter 7 Classzone Notes o o o o Key Concepts: 7.1: In humans, females have the sex chromosomes XX, while males have the sex chromosomes XY. In a cross, males determine the offspring’s gender. Males have only one copy of each gene on the x chromosome, so all of those genes are expressed in their phenotype. Two alleles of autosomal genes interact to produce phenotype. 7.2: Phenotype is affected by many different factors. It is rarely the result of a simple dominant/recessive between two alleles of a gene. Often, there are more than two possible alleles of a gene. Incomplete dominance produces an intermediate phenotype (mix.) Codominance results in both alleles being fully and separately expressed. Many traits are polygenic (controlled by several genes.) Interactions between genes and the environment also affect phenotype. 7.3: Genes can be mapped to specific locations on chromosomes. Studies of wild type and mutant fruit flies led to a new understanding of genetics. Linked genes are often inherited together (genetic linkage.) During meiosis, linked genes can be separated from each other when parts of chromosomes are exchanged. By studying the frequency of crossing over between chromosomes, a linkage map that shows the approximate distance between genes on a chromosome can be made. 7.4: A combination of methods is used to study human genetics. Although most traits do not follow a simple and dominant recessive pattern, single- gene traits are important in the study of human genetics. Several genetic disorders are caused by a single gene with dominant and recessive alleles. Carriers are people who have an allele for a genetic disorder but do not the express the allele in their phenotype. The patterns of genetic inheritance can be studied in families by pedigree analysis. Karyotypes can show large changes in chromosomes. Vocabulary: Carrier: Organism whose genome contains a gene for a certain trait or disease that is not expressed in the organism’s phenotype Codominance: Heterozygous genotype that equally expresses the traits from both alleles Incomplete dominance: Heterozygous phenotype that is a blend of the two homozygous phenotypes Karyotype: Image of all the chromosomes in a cell Linkage map: Diagram that shows the relative locations of genes on a chromosome Pedigree: Chart of the phenotypes and genotypes in a family that is used to determine whether an individual is a carrier of a recessive allele Polygenic trait: Trait that is produced by two or more genes Sex-linked gene: Gene that is located on a sex chromosome (X/Y) X Chromosome Inactivation: Process that occurs in female mammals in which one of the X chromosomes is randomly turned off in each cell. Quizzes: 7.1: Sex linked genes are expressed differently in different cells of a female because one of the two x chromosomes is inactivated at random in each cell. The allele for Huntington’s disease is passed on in the population if fatal because people aren’t affected until after they have children. The probability of two cystic fibrosis carriers having a child with cystic fibrosis is 25%. The X and Y chromosomes are different in that the x chromosome has many genes that affect traits. Sex linked traits are more common in males. 7.2: The heterozygote in an incomplete dominance pattern of heredity can be recognized if the phenotype is somewhere between the phenotypes of the two homozygotes. Incomplete dominance and Codominance are similar in that neither allele is completely dominant or recessive. There is a large variation of phenotypes in polygenic inheritance because many genes interact for the same trait to produce a continuous range of phenotypes. Epistasis is the interference of gene expression by another gene. Identical twins can vary in appearance when they are born if the conditions within the uterus are different (such as location and amount of received nutrients,) affecting phenotype. 7.3: The most common phenotype in a species is wild type. Thomas Hunt Morgan reached the conclusion that chromosomes assort independently during meiosis. The distance between two genes is related to the frequency of crossing over in that the farther apart two genes are, the more likely they will be separated by crossing over. A linkage map shows the relative location of genes on a chromosome. 7.4: A karyotype is a chart showing all the chromosomes in a cell. A male cannot be a carrier for hemophilia because he has only one x chromosome. Hemophilia is a sex linked, genetic disorder. In a pedigree, an open square represents a male without the phenotype. A colorblind female must have the genotype XmXm. 9 Jack Bowers Biology, Pd. 6 (Doucette) Chapter 8 Classzone Notes Vocabulary: Anticodon: set of three nucleotides in a tRNA molecule that binds to a complementary mRNA codon during translation Bacteriophage: Virus that infects bacteria Base pairing rules: Rule that describes how nucleotides form bonds in DNA: adenine (A) – Thymine (T) and guanine (G) – Cytosine (C) Central Dogma: Theory that states that, in cells, information only flows from DNA to RNA to proteins. Codon: Sequence of three nucleotides that codes for one amino acid DNA polymerase: Enzyme that makes bonds between nucleotides, forming an identical strand of DNA during replication Double helix: Model that compares the structure of a DNA molecule, in which two strands wind around one another, to that of a twisted ladder. Exon: Sequence of DNA that codes for information for protein synthesis Frameshift mutation: mutation that involves the insertion or deletion of a nucleotide in the DNA sequence Intron: Segment of a gene that does not code for an amino acid. Messenger RNA (mRNA): Form of RNA that carries genetic information from the nucleus to the cytoplasm, where it serves as a template for protein synthesis Mutagen: Agent that can induce or increase the frequency of mutation in organisms Mutation: Change in the DNA sequence Nucleotide: Monomer that forms DNA and has a phosphate group, a sugar, and a nitrogen-containing base. Operon: Section of DNA that contains all of the code to begin transcription, regulate a transcription, and build a protein; includes a promoter, regulatory gene, and structural gene Point mutation: Mutation that involves a substitution of only one nucleotide Promoter: Section of DNA to which RNA polymerase binds, starting the transcription of mRNA Replication: Process by which DNA is copied Ribosomal RNA (rRNA): RNA that is in the ribosome and guides the translation of mRNA into a protein; also used as a molecular clock RNA: Nucleic acid molecule that allows for the transmission of genetic information and protein synthesis RNA Polymerase: Enzyme that catalyzes the synthesis of a complementary strand of RNA from a DNA template Start Codon: Codon that signals to ribosomes to begin translation; codes for the first amino acid in a protein. Stop Codon: Codon that signals to ribosomes to stop translation Transcription: Process of copying a nucleotide sequence of DNA to form a complementary strand of mRNA Transfer RNA (tRNA): Form of RNA that brings amino acids to ribosomes during protein synthesis Translation: Process by which mRNA is decoded and a protein is produced Key Concepts: 8.1: DNA was identified as genetic material through a series of experiments. Griffith discovered a “transforming principle” which Avery later identified as DNA. Hershey and Chase’s experiments with bacteriophages conclusively demonstrated that DNA is the genetic material. 8.2: DNA structure is the same in all organisms. DNA is a polymer made up of four types of nucleotides. Watson and Crick discovered that DNA consists of two strands of nucleotides bonded together into a double helix structure. Nucleotides always pair up the same way: C-G, A-t 8.3: DNA replication copies the genetic information of a cell. During replication, a DNA molecule separates into two strands. Each strand serves as a template for building a new complementary strand through a rapid, accurate process involving DNA polymerase and other enzymes. 8.4: Transcription converts a gene into a single-stranded RNA molecule. The transcription process is similar to DNA replication and makes three types of RNA. Messenger RNA is an intermediate molecule that carries DNA’s instructions to be translated. 8.5: Translation converts an mRNA message into a polypeptide, or protein. This process occurs on ribosomes, which are made of rRNA and proteins. Transfer RNA molecules bring amino acids to the growing protein by selectively pairing with mRNA codons. 8.6: Gene expression is carefully regulated in both prokaryotic and eukaryotic cells. In prokaryotes, transcription is the primary point of control. In eukaryotes, gene expression is controlled at many points, including RNA processing. 8.7: Mutations are changes in DNA that may or may not affect phenotype. Some affect a single gene, and others affect an entire chromosome. Mutations may occur naturally, or they may be caused by mutagens. A mutation that does not affect phenotype is called silent. Mutations in sperm or egg cells can be passed to offspring. Quizzes: Section 8.1: 1. Hershey and Chase found radioactivity inside the bacterial cells only when the phage DNA contained radioactive phosphorus. 2. Frederick Griffith observed in his experiments that live S bacteria killed mice. 10 3. Oswald Avery learned from his experiments that no bacterial transformation occurred when DNA was destroyed. 4. Avery concluded that DNA was the transforming principle 5. Most scientists in the early 1900s believed that protein carried the genetic material in cells. Section 8.2: 1. A nucleotide is a unit made of a sugar, a phosphate group, and a nitrogen-containing base. 2. The four bases of DNA are A, T, G, and C. (adenine, thymine, guanine, and cytosine) 3. Chargaff’s rules are A = T and C = G 4. Rosalind Franklins DNA x-ray suggested that DNA is a double stranded helix of constant width. 5. If one strand of DNA has the sequence ATTGAT, its complementary strand will be TAACTA Section 8.3: 1. Semi conservative replication means that each new double helix contains one original strand and one new strand. 2. The goal of DNA replication is to ensure that every cell has a complete set of identical DNA. 3. The function of DNA polymerase is to bond nucleotides together. 4. The feature of replication that ensures that DNA is copied quickly is that replication occurs in thousands of place at once. 5. A cell ensures that no errors are introduced during replication by using DNA polymerase to proofread and correct the new DNA. Section 8.4: 1. The molecule mRNA carries information from a gene to the ribosomes. 2. According to the central dogma, information flows from DNA to RNA to protein. 3. In eukaryotes, transcription occurs in the nucleus. 4. DNA is not made during transcription. 5. RNA is different from DNA in that RNA is single-stranded. Section 8.5: 1. The molecule tRNA carries the amino acid coded by mRNA to the ribosome. 2. Three bases code for a single amino acid. 3. The codon AUG would be paired with the anticodon UAC 4. If the mRNA reading frame is changed, the amino acid sequence of the resulting protein changes. 5. The ribosome forms the peptide bonds that link amino acids in a protein. 1. 2. 3. 4. 5. 1. 2. 3. 4. 5. Section 8.6: The lac operon switches off when a repressor protein binds to the operator. A promoter is a DNA sequence that allows a gene to be transcribed. An intron is not part of an operon. Transcription factors, in eukaryotic cells, help RNA polymerase know where a gene starts. Exons are not removed during mRNA processing. Section 8.7: A translocation is a chromosomal mutation. One base is affected in a point mutation. An example of a frameshift mutation is the changing of the sentence THE CAT ATE THE RAT to THE CAT ATA ETH ERA T. A mutation must occur in a germ cell if it is passed to offspring. A mutagen is an agent in the environment that can change DNA. 11 Jack Bowers, Pd. 6 2.27.2009 Chapter 9 Notes Chapter 9 Study Guide: 9.1 A restriction enzyme is an enzyme that can cut DNA sequences, acting as a pair of DNA scissors. Five ways in which scientists study and manipulate DNA: Using artificial nucleotide sequence genes Using artificial gene copies to study their expression Using chemical mutagens to change DNA sequences Using computers to analyze and organize data Using enzymes to cut and copy DNA o 9.2 PCR is an enzyme that copies DNA segments PCR is useful in that it produces copies of DNA at a much faster rate than normal DNA replication. o 9.3 DNA Fingerprinting: Representation of parts of an individual’s DNA. Shows a person’s identity at the molecular level Made by running DNA fragments through gel and analyzing the pattern of bands on the gel (gel electrophoresis) Based on the variation of DNA within people Identification through DNA fingerprinting depends on probability by showing how likely it is that there will be a DNA match. DNA fingerprinting is used for identification in legal cases and proving or disproving relationships. o 9.4 Clone: A genetically identical copy of a gene or organism In nature: Regeneration in organisms such as starfish Mammal Cloning: Artificial process of removing an egg’s nucleus and inserting the nucleus of the organism to be cloned. Potential benefit: Organ donations Concerns: Low success rate, takes numerous tries, clone might not be as healthy as original organism. Genetic Engineering is the changing of an organism’s DNA to give the organism new traits. Recombinant DNA is DNA that contains genes from more than one organism. o 9.5 Genomics is the study of genomes Compares DNA within species Helps researchers find disease causing genes and understand how medications work. Shows the interactions between genes. Begins with gene sequencing, which determines the nucleotide order in genes. Includes the Human Genome Project, which sequenced all the DNA base pairs. Scientists working on this project are still investigating the identification of genes. o 9.6 Genetic screening tests DNA to determine the risk of genetic disorders. Gene therapy replaces missing or defective genes. Two technical challenges in this process are Correct Genes must be added to correct genes. Gene expression must be regulated. One experimental method for the treatment of cancer is the stimulating of the immune system to fight cancer cells. Chapter 9 Notes o Restriction enzymes cut DNA at a specific nucleotide sequence called a restriction site. o Gel electrophoresis is used to separate DNA fragments by size Smaller fragments move faster and further than larger fragments. DNA shows as bands on gel. o PCR copies specific DNA segments. o DNA Fingerprint: The banding pattern that results from gel electrophoresis. Based on parts of an individual’s DNA that can be used for identification and the non-coding regions of DNA. The number of sequence repeats differs between people. Used for criminal cases and paternity tests. A type of restriction map. o Transgenic Organism: Organism that has one or more genes from another organism. o 12 Jack Bowers Biology Period 6 (Doucette) Classzone.com Biology Chapter 10 Notes A. B. 1. 2. 3. 4. 5. C. Vocabulary: Analogous structure: Body part that is similar in function as a body part of another organism but is structurally different. Artificial selection: Process by which humans modify a species by breeding it for certain traits. Biogeography: Study of the distribution of organisms around the world. Catastrophism: Theory that states that natural disasters such as floods and volcanic eruptions shaped Earth’s landforms and caused extinction of some. Evolution: Theory of change in species over time; process of biological change by which descendents come to differ from their ancestors. Fitness: Measure of an organism’s ability to survive and produce offspring relative to other members of a population. Fossil: Trace of an organism from the past. Gradualism: Principle that states that the changes in landforms result from slow changes over a long period of time. Homologous Structure: Body part that is similar in structure on different organisms but performs different functions. Natural selection: Mechanism by which individuals that have inherited beneficial adaptations produce more offspring on average than do other individuals. Paleontology: Study of fossils or extinct organisms. Population: All of the individuals of a species that live in the same area. Uniformitarianism: Theory that proposes that present geological processes are the key to the past. Variation: Differences in physical traits of an individual from the group to which it belongs. Vestigial structure: Remnants of an organ or structure that functioned in an earlier ancestor. Key Concepts: There were theories of biological and geologic change before Darwin. Early biologists suggested that different species might have shared ancestors, and geologists observed that new species appeared in the fossil record. Charles Lyell proposed the theory of uniformitarianism to explain how present observations explain past events. Darwin’s voyage provided insights into evolution. Darwin observed variation between island species on his voyage, such as with the Galos tortoises. He noticed that species have adaptations that allow them to better survive in their environments. He also observed fossil evidence of species changing over time. Darwin proposed natural selection as a mechanism for evolution. Natural selection is a mechanism by which individuals that have inherited beneficial adaptations produce more offspring on average than do other individuals. Natural selection is based on four principles: overproduction, variation, adaptation, and descent with modification. Evidence of common ancestry among species comes from many sources. Fossil evidence is a record of change in a species over time. The study of biogeography showed that species could adapt to different environments. Two species that exhibit similar traits during development likely have a common ancestor. Vestigial and homologous structures also point to a shared ancestry. New technology is furthering our understanding of evolution. Modern techniques, such as DNA sequence analysis and molecular fingerprinting, continue to provide new information about how evolution occurs. Evolution is a unifying theme of all the fields of biology today. Quizzes: 1. Catastrophism is the theory that natural disaster shaped Earth’s landforms and caused species to become extinct. Linnaeus is the scientists who developed a classification system based on similarities. Two individuals of the same species must be able to reproduce and have fertile offspring. The idea that fossils are traces of organisms that lived in the past was not commonly believed in the 1700s. Uniformitarianism is the theory of geologic change accepted by today’s scientists. 2. Darwin saw adaptations such as the length of the neck and legs in the tortoises of the Galapagos Islands. The variations in the Galapagos finches seemed well suited to the animals’ environment and diet. The variations in the Galapagos finches seemed well suited to their environment and diet. Darwin believed that the Earth was older than 6000 years as a result of finding fossils that were similar but not the same as living species. A long, pointed beak might be an adaptation for picking insects out of tree bark. 3. Sexual reproduction is not a main principle of the theory of natural selection. 13 Artificial and natural selection differ in that the environment, not humans, acts as the selecting agent in natural selection. A population is all of the individuals of a species that lives in an area. Fitness is a measure of the ability to survive and produce the most offspring in an organism. Natural selection cannot cause variations, because natural selection works only on existing variations. 4. Analogous structures are similar in structure but different in function. I would expect to find the most primitive fossils in a bottom rock layer. An adaptation is a not a source of evidence of evolution. The similar structures of fish gills and mammal ears in the embryonic stage indicate that fish and mammals had a distant common ancestor. Bird wings and insect wings are analogous structures. 5. A transitional fossil has characteristics of two groups of organisms. Through DNA sequencing, we can learn about evolution that the more similar the DNA sequences of two organisms are, the more closely related they are. Because most organisms don’t form fossils after they die, the fossil record is incomplete. If the fossil of a dinosaur that had feathers was found, it could be inferred that birds and reptiles had a common ancestor. The modern synthesis of evolutionary theory is the use of modern molecular genetics to study natural selection. 14 Jack Bowers Biology (Doucette) Pd. 6 Chapter 11 Classzone Notes Vocabulary: Allele frequency: Proportion of one allele, compared with all the alleles for that trait, in the gene pool. Behavioral isolation: Isolation between populations due to differences in courtship or mating behavior. Bottleneck effect: Genetic drift that results from an event that drastically reduces the size of a population. Coevolution: Process in which two ore more species evolve in response to changes in each other. Convergent evolution: Evolution toward similar characteristics in unrelated species, resulting from adaptations to similar environmental conditions. Directional selection: Pathway of natural selection in which one uncommon phenotype is selected over a more common phenotype. Disruptive selection: Pathway of natural selection in which two opposite, but equally uncommon, phenotypes are selected over the most common phenotype. Divergent evolution: Evolution of one ore more closely related species into different species; resulting from adaptations to different environmental conditions. Extinction: Elimination of a species from Earth. Founder effect: Genetic drift that occurs after a small number of individuals colonizes a new area. Gene Flow: Physical movement of alleles from one population to another. Gene pool: Collection of alleles found in all of the individuals of a population. Genetic drift: Change in allele frequencies due to chance alone, occurring most commonly in small populations. Geographic isolation: Isolation between populations due to physical barriers. Hardy-Weinberg equilibrium: Condition in which a population’s allele frequencies for a given trait do not change from generation to generation. Microevolution: Observable change in the allele frequencies of a population over a few generations. Normal distribution: Distribution in a population in which allele frequency is highest near the mean range value and decreases progressively toward each extreme end. Punctuated equilibrium: Theory that states that speciation occurs suddenly and rapidly followed by long periods of little evolutionary change. Reproductive isolation: Final stage in speciation, in which members of isolated population are either no longer able to mate or not longer able to produce viable offspring. Sexual selection: Selection in which certain traits enhance mating success; traits are, therefore, passed on to offspring. Speciation: Evolution of two or more species from one ancestral species. Stabilizing selection: Pathway of natural selection in which intermediate phenotypes are selected over phenotypes at both extremes. Temporal Isolation: Isolation between populations due to barriers related to time, such as differences in mating periods or differences in the time of day that individuals are most active. Key Concepts: A population shares a common gene pool. Genetic variation in a gene pool can be measured through allele frequencies. Genetic variation increases the chance that some members of a population will be able to adapt to their environment. Populations, not individuals, evolve. Natural selection acts on distributions of traits in a population. Directional selection occurs when one extreme phenotype is advantageous for survival. If intermediate phenotypes are advantageous, they become more common through stabilizing selection. In the process of disruptive selections, extreme, phenotypes are selected for. Natural selection is not the only mechanism through which populations evolve. Gene flow is the movement of alleles between populations. Changes in allele frequencies due to chance alone can occur through genetic drift. If certain traits increase mating success, those traits can become more common through sexual selection. Hardy-Weinberg equilibrium provides a framework for understanding how populations evolve. A population in HardyWeinberg equilibrium is not evolving. The conditions required for this equilibrium are rarely met in nature. However, HardyWeinberg equilibrium provides a framework for understanding the factors that can lead to evolution. New Species can arise when populations are isolated. Reproductive isolation occurs when members of two populations are no longer able to mate successfully. It is the final stage in speciation- the rise of two or more species from one existing species. Isolation can be due to behavioral, geographic, or temporal barriers. Evolution occurs in patterns. Evolution through natural selection can have direction, and its effects add up over many generations. The evolutionary paths of two ore more species can become connected through the process of Coevolution. Extinction and speciation events also appear in patterns in the fossil record. Quizzes: 11.1: Genetic variation comes from mutation and recombination. There are 200 alleles for connected earlobes in the gene pool of 100 people. The frequency of a recessive allele for red flower color in a population of 100 plants (20 plants are homozygous dominant, 60 are heterozygous, and 20 are homozygous recessive) is %50. A mutation in a body cell cannot change the variation in the gene pool, because the mutation cannot be passed on to offspring. Hybridization occurs in nature when individuals of different species cannot find mates of their own species. 11.2: Stabilizing selection increases the number of individuals with an intermediate phenotype. 15 The most common phenotype is found in the middle range in a normal distribution. Directional selection is the recent increase in antibiotic-resistant bacteria. Disruptive selection increases the numbers of individuals with extreme phenotypes. Microevolution does not occur in a single population. 11.3: A showy trait in males becomes established in a population because males with a showy trait will mate more often and be more likely to pass the allele for the trait to offspring. A squirrel building a new nest on another branch of the same tree as its old nest is not an example of gene flow. The bottleneck effect and founder effect are similar in that they both result in loss of certain alleles from their gene pools. Genetic drift is undesirable in a population because a population with little variation is less likely to survive if the environment changes. Gene flow might benefit a small population by increasing variation in the gene pool. 11.4: A stable gene pool does not lead to evolution. A population that is in Hardy-Weinberg equilibrium is not evolving. The condition of immigration occurring but not emigration will not keep a population in equilibrium. If the frequency of an r allele in a population is 0.4, the frequency of an R allele at the same loci will be 0.6. If a population is no longer in equilibrium, it will begin to evolve. 11.5: Speciation is the formation of two species from one existing species. An example of behavioral isolation is the changing of a firefly’s flash pattern due to a mutation. Chemical scents are called behavioral barriers because scents are signals that lead to mating behavior. An example of a behavioral barrier is an earthquake that divides a population of small mice. An example that does not display temporal isolation is the case of two populations of meadowlarks not mating because of not having the same songs. 11.6: Coevolution is the process in which two or more species evolve in response to each other. If all the grass dies and bare soil predominates in the future environment of a lizard population, the allele for brown skin color will gradually increase in frequency. Convergent and divergent evolution differ in that unrelated species evolve similar characteristics in convergent evolution. An example of coevolution is the shared effort of flowers and bees making structures that allow each other to easier pollinate/collect nectar. The pattern in the fossil record of rapid bursts of speciation followed by long periods of evolutionary stability describes punctuated equilibrium. Chapters 18 & 31 Notes (some information taken from classzone.com ‘flipcards’) Capsid: Protein shell that surrounds a virus Faculative Aerobe: Organism that can live with or without oxygen Obligate Aerobe: Prokaryote that cannot survive without the presence of oxygen. Prion: Infectious agent that consists of a protein fragment that can cause other proteins to fold incorrectly Vaccine: Substance that stimulates an immune response Bioremeditation: Process by which humans use living things to break down pollutants Epidemic: Rapid outbreak of disease that affects many people Lytic infection: Infectious pathway of a virus in which the host cell is destroyed Plasmid: Circular piece of genetic material found in bacteria that can replicate separately from the DNA of the main chromosomes Toxin: Poison released by an organism Antibiotic: Chemical that kills or slows the growth of bacteria Endospore: Prokaryotic cell with a thick protective wall surrounding its DNA Lysogenic Infection: Infectious pathway of a virus in which host cells are not immediately destroyed Pathogen: Agent that causes disease; different pathogens have different antigens; there are different types: Those that cause illness by destroying cells Those that release toxic chemicals (infecting cells) Virus: Infectious particle made of only a strand of DNA or RNA surrounded by a protein coat (capsid) Invade host to multiply Retrovirus: Virus that contains RNA and uses the enzyme reverse transcriptase to make a DNA copy. Fungi: Can be single or multi celled Takes nutrients from host cells Occurs in warm, damp places 16 Example: Athletes foot Protozoa: Single celled organisms Use host to complete life cycle Take host nutrients Example: Malaria Parasites: Multi-cellular organisms Example: Tapeworms Grow and feed on host Some have the potential to kill their host Pathogen contact: Direct example: Touching infected surfaces Indirect example: Inhaling infected air Conjugation: Process by which a prokaryote transfers part of its chromosome to another prokaryote Flagellum (plural: Flagella): Whiplike structure outside of a cell used for movement Obligate anaerobe: Prokaryote that cannot survive in the presence of oxygen Prophage: DNA of a bacteriophage inserted into a host cell’s DNA Viroid: Infectious particle made of single stranded RNA without a protein coat, that almost always uses plants as their host Bacteriophage: Virus that infects bacteria Allergy: Immune response that occurs when the body responds to a nondisease-causing antigen, such as pollen or dander Antibiotic Resistance: Process by which bacteria mutate so that they are no longer affected by an antibiotic Antigen: Protein marker that helps the immune system identify foreign particles B Cell: White blood cell that matures in the bone marrow and produces antibodies that fight off infection; also called a B-lymphocyte Germ Theory: Theory that states that diseases are caused by microscopic particles called pathogens Leukemia: Cancer of the bone marrow that weakens the immune system by preventing white blood cells from maturing Opportunistic infection: Infection cause by a pathogen that a healthy immune system would normally be able to fight off T Cell: White blood cell that matures in the thymus and destroys infected body cells by causing them to burst; also called a Tlymphocyte Acquired immune deficiency syndrome (AIDS): Condition characterized by several infections and very few T cells Comes after HIV Most commonly caused by infected medical needles Allergen: Antigen that does not cause disease but produces an immune response Anaphylaxis: Severe allergic reaction that causes airways to tighten and blood vessels to leak Antibody: Protein produced by B cells that helps to destroy pathogens Make pathogens ineffective by clumping them together for easier destruction Antiseptic: Chemical, such as soap or vinegar, that destroys pathogens outside of the body Human Immunodifiency virus (HIV): Virus that weakens the immune system by reproducing in and destroying T cells causes AIDS and/or pneumonia Immune system: Body system that fights off infections; uses the following… Skin: Physical barrier against infection (secretes sweat and oil to create a inhospitable environment for pathogens) Mucous membrane: Traps pathogens; commonly found where there is a permanent opening in the skin, such as the ears and nose Circulatory system: Transports cells to infections Interferon: Type of protein, produced by body cells, that prevents viruses from replicating in infected cells Memory Cell: Specialized white blood cells that contributes to acquired immunity by acting quickly to a foreign substance that infected the body previously Immunity: Active immunity: Immunity that occurs after the body responds to an antigen Passive immunity: Immunity that occurs without the body undergoing an immune response; source example: mother’s milk Phagocyte: Cell that destroys other cells by surrounding and engulfing them Tissue Rejection: Process by which a transplant recipient’s immune system makes antibodies against the protein markers on the donor’s tissue; can result in the destruction of the donor tissue Vector: Organism, such as a mosquito or tick, that transfers pathogens from one host to another Immune responses: Specific responses: Respond to different pathogens in different ways Start with detection of antigens 17 Examples: o Cellular Immunity: Uses T cells to destroy infected cells o Humoral Immunity: Uses B cells to produce antibodies Nonspecific reactions: Respond to different pathogens in the same way; Examples… Inflammation (swelling, heat increase, redness, itching, pain) Fever: Low fever helps white blood cells mature, while a high fever may cause seizures, brain damage, or death Jack Bowers Pd. 6 Biology (Doucette) Chapter 29 Notes Vocabulary: Action potential: Fast, moving change in electrical charge across a neuron’s membrane; also called an impulse. Addiction: Uncontrollable physical and mental need for something. Autonomic nervous system: Division of the peripheral nervous system that controls involuntary functions. Axon: Long extension of the neuron membrane that carries impulses from one neuron to another. Brain stem: Structure that connects the brain to the spinal cord and controls breathing and heartbeat. Central Nervous System (CNS): Part of the nervous system that interprets messages from other nerves in the body; includes the brain and spinal cord. Cerebellum: Part of the brain that coordinates and regulates all voluntary muscle movement and maintains posture and balance. Cerebral cortex: Layer of gray matter on the surface of the cerebrum that receives information and generates responses. Cerebrum: Largest part of the brain, coordinating movement, thought, reasoning, and memory; includes the cerebral cortex and the white matter beneath it. Cone cell: Sensory neuron in the eye that detects color. Dendrite: Branchlike extension of a neuron that receives impulses from neighboring neurons. Depressant: Drug that causes fewer signals to be transmitted between neurons. Desensitization: Process by which neurons in the brain break down neurotransmitter receptors in response to a larger amount of neurotransmitter in the synapse than usual. Endocrine system: Body system that controls growth, development, and responses to the environment by releasing chemical signals into the bloodstream. Gland: Organ that produces and releases chemicals that affect the activities of other tissues. Hair cell: Mechanoreceptor in the inner ear that detects sound waves when bent. Hormone: Chemical signal that is produced in one part of an organism and affects cell activity in another part. Hypothalamus: Small area of the midbrain that plays a role in the nervous and endocrine systems. Nervous system: Body system that controls sensation, interpretation, and response; includes the brain, spinal cord, and nerves. Neuron: Cell of the nervous system that transmits impulses between the body systems as well as interprets and stores some messages in the brain. Neurotransmitter: Chemical that transmits a nervous system’s signal across a synapse. Parasympathetic nervous system: Division of the peripheral nervous system that calms the body and helps the body to conserve energy Peripheral nervous system (PNS): Division of the nervous system that transmits impulses between the central nervous system and other organs in the body. . Pituitary gland: Area in the middle of the brain that makes and releases hormones that control cell growth and osmoregulation (water levels in the blood.) Key Concepts: 1) How organ systems communicate: The nervous system and endocrine system provide the means by which organ system communicate. The body’s nervous system and endocrine system generate, interpret, and deliver messages that help to maintain homeostasis. The two systems have different rates of communication because they send their signals by different methods. 2) Neurons. The nervous system is composed of highly specialized cells. Neurons are specialized cells of the nervous system that have long extension for transmitting signals over long distances. These cells produce, receive, and transmit impulses called action potentials. 3) The senses. The senses detect the internal and external environments. The senses use five types of receptors and many specialized cells (including rod, cone, and hair cells) that detect physical and chemical stimuli. 18 4) Central and Peripheral Nervous Systems. The central nervous system interprets information, and the peripheral nervous system gathers and transmits information. The CNS and PNS work together. In the CNS, the cerebrum controls conscious thought and interprets sensory signals from throughout the body. The PNS delivers messages from the body toward and away from the CNS. 5) Brain function and Chemistry. Scientists study the function and chemistry of the brain. Imaging techniques allow scientist s to look at the brain without having to have a patient undergo surgery. This technology can show chemical and physical changes in brains that have severe illnesses. Both prescription and illegal drugs alter brain chemistry and neuron structure. 6) Endocrine System and Hormones. The endocrine system produces hormones that affect growth, development, and homeostasis. The glands of the endocrine system produce chemical signals called hormones that act throughout the body. The hypothalamus is a gland that interacts with the nervous and endocrine systems. Hormone imbalances can cause severe illnesses, such as hypothyroidism, diabetes, and Addison’s disease. Quizzes: 1) Responding to pain is the most likely activity to be controlled by the nervous system. Because all parts of the nervous system are physically connected in a network, the nervous system is able to respond quickly to a stimulus. The bloodstream is necessary for the endocrine system to respond to stimuli. The endocrine system does not control immediate processes. The nerve network is part of the peripheral nervous system. 2) A neuron receives messages through its dendrites. Motor neurons pass messages to muscles. Resting potential is the difference in electrical charge across a neuron’s cell membrane. The rushing of sodium ions into the axon (making it positive) causes an action potential to travel down an axon. Neurotransmitters are found in the synapses. 3) Mechanoreceptors are the type of sensory receptor that would detect a fly landing on your arm. Cornea, pupil, lens, retina;, is the correct path of light through the eye. Taste buds are chemoreceptors. 4) The occipital lobe is the part of the cerebral cortex that processes visual information. The CNS is the part of the nervous system that is composed of interneurons that interact with other nerves in the body. A person’s cerebellum has likely been damaged if a person has trouble maintaining posture and balance after an accident. A reflex arc is such a rapid response to a stimulus because the signal doesn’t have to go first to the brain before muscles respond. The somatic nervous system is the branch that controls your kicking a soccer ball. 5) MRI scan technology does not utilize x-rays. Only part of the brain is affected by too much or too little neurotransmitter because each neurotransmitter targets only a specific part of the brain. Sensitization and desensitization are similar in that they cause neurons to change the number of receptors on their cell membranes. A stimulant causes a behavior change by increasing the number of action potentials generated by increasing the amount of neurotransmitter in the synapse. When a person develops a tolerance to a drug, it takes larger doses of the drug to produce the same effect. 6) The hypothalamus and pituitary glands work together in that the hypothalamus produces GHRH, which causes the pituitary to produce GH. A cell must have the appropriate hormone receptor in order to be a target cell for a hormone. The idea that steroid hormones bind to receptors on their target cells’ membranes is incorrect. The ovary gland does not produce glucagon. A hormone imbalance can cause a large variety of symptoms because a hormone may have many target cells in different parts of the body. 19 Jack Bowers Pd. 6 Biology (Doucette) 5.5.2009 Chapter 30 Notes Vocabulary: Alveolus: Tiny, thin-walled structure across which oxygen gas is absorbed and carbon dioxide is released in the lungs. Artery: Large blood vessel that carries blood away from the heart. Asthma: Condition in which air pathways in the lung constrict, making breathing difficult. Atrium: Small chamber in the human heart that receives blood from the veins. Blood pressure: Force with which blood pushes against the wall of an artery. Capillary: Tiny blood vessel that transports blood between larger blood vessels and other tissues in the body. Circulatory system: Body system that transports nutrients and wastes between various body tissues; includes heart, blood, and blood vessels. Diaphragm: Thin muscle below the rib cage that controls the flow of air into and out of the lungs. Diastolic pressure: Pressure in an artery when the left ventricle relaxes. Emphysema: Condition of the lungs in which the surface area of alveoli decreases, making breathing difficult. Heart: Muscles in the chest that moves blood throughout the body. Hemoglobin: Iron-rich protein in red blood cells that allows the cell to absorb oxygen gas. Lung: Organ that absorbs oxygen gas from air that an organism inhales. Lymph: Collection of interstitial fluid and white blood cells that flows through the lymphatic system. Lymphatic system: Body system that consists of organs, vessels, and nodes through which lymph circulates. Lymphocyte: White blood cell that plays a role in an immune response; see B cell and T cell. Node: Organ located along the lymphatic vessels that filters bacteria and foreign particles from lymph. Pacemaker: Collection of cells that stimulates the pumping action of the heart. Plasma: Clear yellowish fluid (about 90% water) that suspends cells in the blood. Platelet: Cell fragment that is produced in the bone marrow and is important for blood clotting. Pulmonary circulation: See pulmonary circuit Red blood cell: Cell that carries oxygen gas from the lungs to the rest of the body. Respiratory system: Body system that brings oxygen into the body and removes carbon dioxide; includes the nose, trachea, and lungs. Rh factor: Surface protein on red blood cells in the ABO blood group. Systemic circulation: See systemic circuit. Systolic pressure: Measure of pressure on the wall of an artery when the left ventricle contracts to pump blood through the body. Trachea: Long structure made of soft tissue that connects the mouth and nose to the lung in humans; a system of thin branching tubes in the bodies of insects that allow for breathing. Valve: Flap of tissue that prevents blood from flowing backward into a blood vessel or heart chamber. Vein: Large blood vessel that carries blood from the rest of the body to the heart. Ventricle: Large chamber in the heart that receives blood from an atrium and pumps blood to the rest of the body. White blood cell: Cell that attacks pathogens. Quizzes: 1. The correct path of blood as it leaves from and returns to the heart is arteries to capillaries to veins. The respiratory and circulatory systems work together in that the circulatory system transports the oxygen and carbon dioxide that are exchanged in the respiratory system. Air passes from the nose, to trachea, to lungs, and finally to alveoli in its path through the respiratory system. The epiglottis prevents food from entering air passages to the lungs. When you inhale, the diaphragm flattens and moves downward. 2. The large surface area of the alveoli is needed for sufficient gas exchange. Gas exchange takes place between the capillaries and alveoli. Oxygen is transported in the blood by being bound to hemoglobin in red blood cells. Carbon dioxide moves out of the blood in the lungs because carbon dioxide concentrations are higher in the blood than in the alveoli, so it diffuses out. The destruction of the alveoli (surface area used for gas exchange) causes the lungs to fail in emphysema. 3. The heart valves prevent blood from flowing backward. The contraction of the atria causes the first “lub” sound of the heart beat. An electrical signal from the left ventricle starts the first contraction of the heart. When blood leaves the left ventricle, it goes to the rest of the body. The correct pathway for pulmonary circulation is right ventricle, to lungs, to left atrium. 4. 20 Artery walls must be thicker than vein walls because blood is under greater pressure in arteries than in veins. Veins keep blood moving by using skeletal muscles to push against the veins, causing the valves to open. An advantage of having thin capillary walls is that materials can easily diffuse in and out of the capillaries. Systolic pressure is the pressure on an artery wall when the left ventricle contracts. An obstruction in the artery is bypassed in bypass surgery. Thrombin is not a component of blood clots. Platelets in blood aid in clotting. The fact that red blood cells have no organelles is not correct. A person with type O blood can donate to anyone because type O blood has no protein markers. Therefore, a recipient will not attack it. White blood cells are part of both the circulatory and immune systems. 5. 6. Red blood cells are not a part of the lymphatic system. Interstitial fluid is the fluid that leaks out of blood vessels into spaces between cells. The function of a lymph node is to filter bacteria, viruses, fungi, and cell fragments out of the lymph. The thymus is a structure that develops lymphocytes. Lymph vessels are similar to veins in that both have valves to prevent fluid from flowing backward. Key Concepts: 1. The respiratory and circulatory systems bring oxygen and nutrients to the cells. These two systems work together to maintain homeostasis. The respiratory system moves gases into and out of the blood. The circulatory system transports blood to all parts of the body. 2. The respiratory system exchanges oxygen and carbon dioxide. Gas exchange occurs in the alveoli of the lungs, where oxygen and carbon dioxide diffuse into and out of the blood. Respiratory diseases such as emphysema and asthma interfere with gas exchange. 3. The heart is a muscular group that moves the blood through two pathways. The tissues and structures of the heart make it an efficient pump and allow it to work continuously. The heartbeat consists of two contractions that move blood from the atria to the ventricles. Blood circulates through the pulmonary and systemic pathways. 4. The circulatory system transports materials throughout the body. Arteries, veins, and capillaries transport blood to all the cells. The force with which blood pushes against the wall of an artery is known as blood pressure. The health of the circulatory system can be supported or harmed by lifestyle choices. 5. Blood is a complex tissue that transports materials. Blood is composed mainly of cells, platelets, and plasma. Red blood cells transport gases, white blood cells help fight diseases, and platelets help seal wounds. Proteins in blood determine blood type and RH+ and RH- factors. The ABO group is the most commonly used of all the blood grouping systems. 6. The lymphatic system provides another type of circulation in the body. The lymphatic system collects excess fluid between the cells, filters it, and returns it to the circulatory system. The lymphatic system is also an important part of the immune system. 21 Jack Bowers Pd. 6 Biology (Doucette) 5.8.2009 Chapter 32 Notes Vocabulary: Bile: Fluid released by the liver and gallbladder into the small intestine that aids in the digestion and absorption of fats. Calorie: Measure of energy released from digesting food; one Calorie equals one kilocalorie of heat. Chyme: Partially digested, semi-liquid mixture that passes from the stomach to the small intestine. Dialysis: Treatment in which a patient’s blood is filtered through a machine, the waste is removed, and the cleaned blood is returned to the patient’s body. Digestion: Process by which large, complex molecules are broken down into smaller molecules that can be used by cells. Digestive system: Body system that digests food; includes mouth, esophagus, stomach, pancreas, intestines, liver, gallbladder, rectum, and anus. Esophagus: Tube-shaped tissue of the digestive system that connects the mouth to the stomach. Excretory system: Body system that collects and eliminates wastes from the body; includes the kidneys and bladder. Glomerulus: Tangled ball of capillaries that circulates blood in the kidneys. Kidney: Organ of the excretory system that removes waste from the blood and helps to maintain stable water levels in the body. Microvillus: Small hair-like projection on the surface of a villus in the small intestine. Mineral: Inorganic material, such as calcium, iron, potassium, sodium, or zinc, that is essential to the nutrition of an organism. Nephron: Individual filtering unit of the kidney that removes waste from the blood. Peristalsis: Wavelike involuntary muscle contractions that push food through the organs of the digestive system. Small intestine: Organ of the digestive system that connects the stomach to the large intestine and in which chemical digestion takes place. Sphincter: ring of muscle separates the different organs of the digestive system. Stomach: Muscular sac in the digestive system that breaks down food into a liquid-like mixture. Ureter: Tube of connective tissue that carries urine from each of the kidneys to the bladder. Urinary bladder: Saclike organ that collects and stores urine before it is excreted from the body. Villus: Small finger-like projection in the small intestine that absorbs nutrients. Key Concepts: 1. Cells require many different nutrients. Six types of nutrients are important to maintain homeostasis in the body: water, carbohydrates, proteins, fats, minerals, and vitamins. These nutrients help to maintain fluid balance, cell processes, functions such as digestion and elimination, and tissue building and repair. A balanced diet and adequate Calories are especially important during puberty, a time of rapid growth and development. 2. The digestive system breaks down food into simpler molecules. The digestive system includes the mouth, esophagus, stomach, pancreas, liver, gallbladder, large and small intestines, rectum, and anus. Sphincters and the action of peristalsis keep food moving in one direction through the digestive system. Mechanical and chemical digestion help to break down food into simpler molecules. The process of digestion begins in the mouth and is completed in the duodenum of the small intestine. 3. Nutrients are absorbed and solid wastes eliminated after digestion. Most absorption of nutrients occurs in the small intestine. The small intestine has specialized structures (folds, villi and microvilli) that increase the surface area so that more nutrients can be absorbed. Nutrients diffuse into the circulatory and lymphatic systems and are carried to all the cells. The large intestine absorbs water and eliminates the solid wastes that are byproducts of digestion. 4. The excretory system removes wastes and helps maintain homeostasis. The excretory system includes the skin, lungs, kidneys, ureter, bladder, and urethra. The nephrons in the kidneys filter the blood, reabsorb needed materials, and excrete waste materials in the urine. A person whose kidneys stop functioning must have a kidney transplant or dialysis treatment to maintain the body’s homeostasis.