<p> Ib Exam Biology II Terms</p><p>Topic 1: Statistical analysis 1.1.1 Error bars are a graphical representation of the variability of data 1.1.3 Standard deviation- used to summarize the spread of values around the mean, 68% fall within 1 std dev.</p><p>Topic 2: Cells 2.1.3 Unicellular organisms carry out all the functions of life: metabolism, response, homeostasis, growth, reproduction, nutrition 2.1.7 Multi-cellular organisms show emergent properties: the whole is greater than the sum of its parts 2.1.9 Stem cells retain the capacity to divide and have the ability to differentiate along different pathways 2.2.4 Prokaryotic cells divide by binary fission 2.5.2 Tumors (cancers) are the result of uncontrolled cell division and that these can occur in any organ or tissue 2.5.4 Interphase is an active period in the life of a cell when many metabolic reactions occur, including protein synthesis, DNA replication and an increase in the number of mitochondria and/or chloroplasts 2.5.6 Growth, embryonic development, tissue repair and asexual reproduction involve mitosis</p><p>Topic 3: The chemistry of life 3.1.1 The most frequently occurring chemical elements in living things are carbon, hydrogen, oxygen, and nitrogen. 3.1.2 A variety of other elements are needed by living organisms: sulfur, calcium, phosphorus, iron, and sodium 3.3.2 DNA Bases: Adenine, Guanine, Thymine, Cytosine 3.4.3 DNA replication is semi-conservative: 2 strands: one old, one new 3.6.1 Enzyme- Biological catalysts that enables reactions to occur at faster rates Active site- Site of the enzyme substrate molecule binds to 3.6.4 Denaturation- A structural change in a protein that results in the loss of its biological properties (by heat or pH) 3.7.1 Cell respiration- The controlled release of energy from organic compounds in cells to form ATP 3.7.2 In cell respiration glucose in the cytoplasm is broken down by glycolysis into pyruvate, with a small yield of ATP 3.8.1 Photosynthesis involves the conversion of light energy into chemical energy 3.8.2 Light from the Sun is composed of a range of wavelengths (colors) 3.8.3 Chlorophyll is the main photosynthetic pigment 3.8.5 Light energy is used to produce ATP, and to split water molecules (photolysis) to form oxygen and hydrogen 3.8.6 ATP and hydrogen (derived from the photolysis of water) are used to fix carbon dioxide to make organic molecules Ib Exam Biology II Terms Topic 4: Genetics 4.1.1 Eukaryote chromosomes are made of DNA and proteins</p><p>4.1.2 Gene- Heritable factor that controls a specific characteristic</p><p>Allele- One specific form of a gene, differing from other alleles by one or a few bases only and occupying the same gene locus as other alleles of the gene</p><p>Genome- The whole of he genetic information of an organism</p><p>4.1.3 Gene Mutation- When the sequence of base pairs for the production of amino acids is changed either by affecting one base pair or inserting or deleting a base pair form the gene</p><p>4.2.1 Meiosis is a reduction division of a diploid nucleus to form haploid nucleus</p><p>4.2.2 Homologous Chromosomes- Two chromosomes that carry the same genes but not always the same alleles</p><p>4.2.5 In karyotyping, chromosomes are arranged in pairs according to their size and structure</p><p>4.2.6 Karyotyping is performed using cells collected by chorionic villus sampling or amnicentesis, for pre- natal diagnosis of chromosome abnormalities</p><p>4.3.1 Genotype- Alleles of an organism</p><p>Phenotype- Characteristics of an organism</p><p>Dominant allele- An allele that has the same effect on the phenotype whether it is present in the homozygous or heterozygous state</p><p>Recessive allele- An allele that only has an effect on the phenotype when present in the homozygous state</p><p>Codominant alleles- Pairs of alleles that both affect the phenotype when present in a heterozygote</p><p>Locus- The particular position on homologous chromosomes of a gene</p><p>Homozygous- Having two identical alleles of a gene</p><p>Heterozygous- Having two different alleles of a gene</p><p>Carrier- An individual that has one copy of a recessive allele that causes a genetic disease in individuals hat are homozygous for this allele</p><p>Test cross- Testing a suspected heterozygote by crossing it with a known homozygous recessive</p><p>4.3.3 Some genes have more than two alleles (multiple alleles) Ib Exam Biology II Terms 4.3.6 Some genes are present on the X chromosome and absent from the shorter Y chromosome in humans</p><p>4.3.7 Sex linkage- Genes located on a sex chromosome, preferring one gender more than another</p><p>4.3.9 A human female can be homozygous or heterozygous with respect to sex-linked genes</p><p>4.4.2 In gel electrophoresis, fragments of DNA move in an electric field and are separated according to their size</p><p>4.4.3 Gel electrophoresis of DNA is used in DNA profiling</p><p>4.4.7 When genes are transferred between species, the amino acid sequence of polypeptides translated from them is unchanged because the genetic code is universal</p><p>4.4.12 Clone- A group of genetically identical organisms or a group of cells derived from a single parent cell</p><p>Topic 5: Ecology and Evolution 5.1.1 Species- Group of organisms that can interbreed and produce fertile offspring</p><p>Habitat- Environment in which a species normally lives or the location of a living organism</p><p>Population- Group of organisms of the same species who live in the same area at the same time</p><p>Community- Group of populations living and interacting with each other in an area</p><p>Ecosystem- A community and its abiotic factor</p><p>Ecology- Study of relationships between living organisms and between organisms and their environment</p><p>5.1.2 Autotroph- An organism that synthesizes its organic molecules from simple inorganic substances</p><p>Heterotroph- An organism that obtains organic molecules from other organisms</p><p>5.1.3 Consumers- An organism that ingests other organic matter that is living or recently killed</p><p>Detritivores- An organism that ingests non-living organic matter</p><p>Sapotrophs- An organism that live on or in non-living organic matter, secreting digestive enzymes into it and absorbing the products of digestion</p><p>5.1.5 Food Web- a community of organisms where there are several interrelated food chains</p><p>5.1.6 Trophic Level- The position or level of an organism during its energy seeking activities</p><p>5.1.9 Light is the initial energy source for almost all communities Ib Exam Biology II Terms 5.1.11 Energy transformations are never 100% efficient</p><p>5.1.14 Saprotrophic bacteria and fungi (decomposers) recycle nutrients</p><p>5.4.1 Evolution- The cumulative change in the heritable characteristics of a population</p><p>5.4.3 Populations tend to produce more offspring than the environment can support</p><p>5.4.5 The members of a species show variation</p><p>Topic 6: Human health and physiology 6.1.6 Absorption- Soluble products of digestion absorbed into blood circulation system</p><p>Assimilation- Products of digestion absorbed from blood to body cells and used and stored</p><p>6.2.2 Coronary arteries supply heart muscle with oxygen and nutrients</p><p>6.2.6 Blood is composed of plasma, erythrocytes, leucocytes (phagocytes & lymphocytes) and platelets</p><p>6.3.1 Pathogen- An organism or virus that causes a disease</p><p>6.3.5 Antigens- A molecule or particle recognized as foreign by the immune system that can trigger an immune response</p><p>Antibodies- Immunoglobulin, a globular protein that recognizes an antigen </p><p>6.4.1 Ventilation- System which includes a pumping mechanism that moves air into and out of the lungs efficiently, thereby maintaining the concentration gradient for diffusion</p><p>Gas exchange- The exchange of gases between an organism and its surroundings, including the uptake of oxygen and the release of carbon dioxide in animals and plants</p><p>Cell respiration- The controlled release of energy in the form of ATP from organic compounds in cells</p><p>6.5.1 The nervous system consists of the central nervous system (CNS) and peripheral nerves, and is composed of cells called neurons that can carry rapid electrical impulses</p><p>6.5.3 Nerve impulses are conducted from receptors to the CNS by sensory neurons, within the CNS by relay neurons, and from the CNS to effectors by motor neurons</p><p>6.5.4 Resting Potential- An electrical impulse across a cell membrane when not propagating an impulse</p><p>Action potential- The localized reversal and then restoration of electrical potential between the inside and outside of a neuron as the impulse passes through it</p><p>6.5.7 The endocrine system consists of glands that release hormones that are transported in the blood Ib Exam Biology II Terms 6.5.8 Homeostasis involves maintaining the internal environment between limits, including blood pH, carbon dioxide concentration, blood glucose concentration, body temperature, and water balance</p><p>6.5.12 Type I diabetes- There is an absolute deficiency of insulin, requires regular injections of insulin</p><p>Type II diabetes- more common, body’s cells become less sensitive to the insulin present due to excess insulin in the system </p><p>Option A: Human nutrition and health A.1.1 Nutrient- A chemical substance found in foods that is used in the human body</p><p>A.1.3 Non-essential amino acids can be synthesized in the body from other nutrients</p><p>A.1.8 Minerals- Are elements in ionic form</p><p>Vitamins- Organic compounds</p><p>Option D: Evolution D.1.3 Comets may have delivered organic compounds to Earth- Comets contain a variety of organic compounds. Heavy bombardment about 4,000 million years ago may have delivered both organic compounds and water to the early Earth</p><p>D.1.6 Living cells may have been preceded by protobionts, with an internal chemical environment different from their surroundings</p><p>D.2.1 Allele frequency- a measure of the relative frequency of an allele at a genetic place (locus) in a population</p><p>Gene pool- the complete set of unique alleles in a species or population</p><p>D.2.2 Evolution involves a change in allele frequency in a population’s gene pool over a number of generations</p><p>D.3.2 Half-life- the time required for something to fall to half its initial value</p><p>D.3.6 At various stages in hominid evolution, several species may have coexisted- H. neanderthalensis & H. Sapiens</p>