cells divide by binary fission. 2.3 Eukaryotic cells. Read pp._____________, EBQ #__________, HW due dates__________________, Quiz date_______ Assessment statement Obj Clarifying notes 2.3.1 Draw and label a diagram of the ultrastructure of a liver cell as an example of an animal cell. 1 The diagram should show free ribosomes, rough endoplasmic reticulum (rER), lysosome, Golgi apparatus, mitochondrion and nucleus. The term Golgi apparatus will be used in place of Golgi body, Golgi complex or dictyosome. 2.3.2 Annotate the diagram from 2.3.1 with the functions of each structure. 2 2.3.3 Identify structures from 2.3.1 in electron micrographs of cells. 2 2.3.4 Compare prokaryotic and eukaryotic cells. 3 Differences should include: DNA versus DNA associated with proteins DNA in cytoplasm versus DNA enclosed in a nuclear envelope no mitochondria versus mitochondria 70S versus 80S ribosomes
alleles, to balance the twin risks of anemia and malaria. 4.2 Introduction to Meiosis. Read pp.____________, EBQ #__________, HW due dates_____________, Quiz date_______ Assessment statement Obj Clarifying 4.2.1 State that meiosis is a reduction division of a diploid nucleus to form haploid nuclei. 1 4.2.2 Define homologous chromosomes. 1 4.2.3 Outline the process of meiosis, including pairing of homologous chromosomes and crossing over, followed by two divisions, which results in four haploid cells. 2 Limit crossing over to the exchange of genetic material between chromatids during prophase I. Names of the stages are required. 4.2.4 Explain that can lead to changes in chromosome number, illustrated by reference to Down syndrome (trisomy 21). 3 The characteristics of Down syndrome are not required. 4.2.5 State that, in karyotyping, chromosomes are arranged in pairs according to 1
and allow a subsequent or health-care professionals or both groups? There are also Essential Biologys about whether or not national governments should interfere with personal freedoms, and whether or not they should be able to ban procedures within the country and possibly also ban citizens travelling to foreign countries where the procedures are permitted. 4.2.7 Analyse a human karyotype to determine gender and whether has occurred. 3 Karyotyping can be done by using enlarged photographs of chromosomes. Aim 7: Online simulations of karyotyping activities are available. 4.3 Theoretical genetics. Read pp.____________, EBQ #__________, HW due dates_______________, Quiz date_______ Assessment statement Obj Clarifying notes 4.3.1 Define genotype, phenotype, dominant allele, recessive allele, codominant 1 Genotype: the alleles of an organism.
breeding of animals, and whether this is distinctively different and always acceptable. The possibility of animals suffering as a result of genetic modification could be considered. 4.4.8 Outline a basic technique used for gene transfer involving plasmids, a host cell (bacterium, yeast or other cell), restriction enzymes (endonucleases) and DNA ligase. 2 The use of E. coli in gene technology is well documented. Most of its DNA is in one circular chromosome, but it also has plasmids (smaller circles of DNA). These plasmids can be removed and cleaved by restriction enzymes at target sequences. DNA fragments from another organism can also be cleaved by the same restriction enzyme, and these pieces can be added to the open plasmid and spliced together by ligase. The recombinant plasmids
instead of binomial names. General names such as “tree” or “fish” should not be used. 5.1.5 Describe what is meant by a food web. 2 5.1.6 Define trophic level. 1 5.1.7 Deduce the trophic level of organisms in a food chain and a food web. 3 Students should be able to place an organism at the level of producer, primary consumer, secondary consumer, and so on, as the terms herbivore and carnivore are not always applicable. 5.1.8 Construct a food web containing up to 10 organisms, appropriate information. 3 5.1.9 State that light is the initial energy source for almost all communities. 1 No reference to communities where food chains start with chemical energy is required. 5.1.10 Explain the energy flow in a food chain. 3 Energy losses between trophic levels include material not consumed or material not assimilated, and heat loss through cell respiration. 5.1.11 State that energy transformations are never 100% efficient. 1 Reference to the second law of thermodynamics is not expected. 5.1.12 Explain reasons for the 3 A pyramid of energy shows
TOK: What difference might it make to scientific work if nature were to be regarded as a machine, for example, as a clockwork mechanism, or as an organism, that is, the Gaia hypothesis? How useful are these metaphors? 5.2.2 Analyse the changes in concentration of atmospheric carbon dioxide using historical records. 3 Data from the Mauna Loa, Hawaii, or Cape Grim, Tasmania, monitoring stations may be used. 5.2.3 Explain the relationship between in concentrations of atmospheric carbon dioxide, methane and oxides of nitrogen and the enhanced greenhouse effect. 3 Students should be aware that the greenhouse effect is a natural phenomenon. Reference should be made to transmission of incoming shorter-wave radiation and re-radiated longer-wave radiation. Knowledge that other gases, including methane and oxides of nitrogen, are greenhouse gases is expected.
5.2.4 Outline the precautionary principle. 2 The precautionary principle holds that, if the effects of a change would be very large, perhaps catastrophic, those responsible for the change must prove that it will not do harm before proceeding. This is the reverse of the normal situation, where those who are concerned about the change would have to prove that it will do harm in order to prevent such changes going ahead. TOK: Parallels could be drawn here between success in deterring crime by increasing the severity of the punishment or by increasing the chance of detection. If the possible consequences of rapid global warming are devastating enough, preventive measures are justified even if it is far from
certain that rapid global warming will result from current human activities. 5.2.5 Evaluate the precautionary principle as a justification for strong action in response to the threats posed by the enhanced greenhouse effect. 3 Aim 8: Consider whether the economic harm of measures taken now to limit global warming could be balanced against the potentially much greater harm for future generations of taking no action now. There are also ethical Essential Biologys about whether the health and wealth of future human generations should be jeopardized, and whether it is right to knowingly damage the habitat of, and possibly drive to extinction, species other than humans. The environmental angle here is that the issue of global warming is, by definition, a genuinely global one in terms of causes, consequences and remedies.
Only through international cooperation will a solution be found. There is an inequality between those in the world who are contributing most to the problem and those who will be most harmed. 5.2.6 Outline the consequences of a global temperature rise on arctic ecosystems. 2 Effects include increased rates of decomposition of detritus previously trapped in permafrost, expansion of the range of habitats available to temperate species, loss of ice habitat, changes in distribution of prey species affecting higher trophic levels, and increased success of pest species, including pathogens. 5.3 Populations. Read pp.________________, EBQ #__________, HW due dates__________________, Quiz date_______ Assessment statement Obj Clarifying notes 5.3.1 Outline how population size is affected by natality, 2 Aim 7: Simulation exercises can be performed.
6.5.2 Draw and label a diagram of the structure of a motor neuron. 1 Include dendrites, cell body with nucleus, axon, myelin sheath, nodes of Ranvier and motor end plates. 6.5.3 State that 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. 1 6.5.4 Define resting potential and action potential (depolarization and repolarization). 1 6.5.5 Explain how a nerve impulse passes along a neuron. 3 Include the movement of Na+ and K+ ions to create a resting potential and an action potential. 6.5.6 Explain the principles of synaptic transmission. 3 Include the release, diffusion and binding of the neurotransmitter, initiation of an action potential in the membrane, and subsequent removal of the neurotransmitter. Aim 7: Data logging can be used to measure changes in conductivity in distilled as
Na+ and K+ diffuse out of salt–agar cubes or dialysing tubing. 6.5.7 State that the endocrine system consists of glands that release hormones that are transported in the blood. 1 The nature and action of hormones or direct comparisons between nerve and endocrine systems are not required. 6.5.8 State that homeostasis involves maintaining the internal environment between limits, including blood pH, carbon dioxide concentration, blood glucose concentration, body temperature and water balance. 1 The internal environment consists of and tissue fluid. 6.5.9 Explain that homeostasis involves monitoring levels of variables and correcting changes in levels by negative feedback mechanisms. 3 6.5.10 Explain the control of body temperature, including the transfer of heat in blood, and the roles of the hypothalamus, sweat glands, skin arterioles and shivering. 3 Aim 7: Data logging using a surface temperature sensor to investigate the warming by nasal passages could be carried out here.
6.5.11 Explain the control of glucose concentration, including the roles of glucagon, insulin and α and β cells in the pancreatic islets. 3 The effects of adrenaline are not required here. 6.1 Digestion. Read pp.______________________, EBQ #________, HW due dates_______________, Quiz date_______ Assessment statement Obj Clarifying notes 6.1.1 Explain why digestion of large food molecules is essential. 3 6.1.2 Explain the need for enzymes in digestion. 3 The need for increasing the rate of digestion at body temperature should be emphasized. 6.1.3 State the source, substrate, products and optimum pH conditions for one amylase, one protease and one lipase. 1 Any human enzymes can be selected. Details of structure or mechanisms of action are not required. Aim 7: Data logging with pH sensors and lipase, and data logging with colorimeters and amylase can be used. 6.1.4 Draw and label a diagram of the digestive system. 1 The diagram should show the mouth, esophagus, stomach, small intestine, large intestine, anus, liver, pancreas
and gall bladder. The diagram should clearly show the interconnections between these structures. 6.1.5 Outline the function of the stomach, small intestine and large intestine. 2 6.1.6 Distinguish between absorption and assimilation. 2 6.1.7 Explain how the structure of the villus is related to its role in absorption and transport of the products of digestion. 3 6.2 The transport system. Read pp._____________, EBQ #________, HW due dates_______________, Quiz date_______ Assessment statement Obj Clarifying 6.2.1 Draw and label a diagram of the heart showing the four chambers, associated blood vessels, valves and the route of blood through the heart. 1 Care should be taken to show the relative wall thickness of the four chambers. Neither the coronary vessels nor the conductive system are required. 6.2.2 State that the coronary arteries supply heart muscle with 1
oxygen and nutrients. 6.2.3 Explain the action of the in terms of collecting blood, pumping blood, and opening and closing of valves. 3 A basic understanding is required, limited to the collection of blood by the atria, which is then pumped out by the ventricles into the arteries. The direction of flow is controlled by and semilunar valves. 6.2.4 Outline the control of the heartbeat in terms of myogenic muscle contraction, the role of the pacemaker, nerves, the medulla of the brain and epinephrine (adrenaline). 2 Histology of the muscle, names of nerves or transmitter substances are not required. Aim 7: Simulation and data logging involving heart rate monitors, or data logging involving an EKG sensor to measure electrical signals produced during muscle contractions, can be used. 6.2.5 Explain the relationship between the structure and function of arteries, 3
a dense network of capillaries. 6.4.4 Draw and a diagram of the ventilation system, including trachea, lungs, bronchi, bronchioles and alveoli. 1 Students should draw the alveoli in an inset diagram at a higher magnification. 6.4.5 Explain the mechanism of ventilation of the lungs in terms of volume and pressure changes caused by the internal and external intercostal muscles, the diaphragm and abdominal muscles. 3 Aim 7: Data logging involving spirometers or ventilation rate monitors is possible here. 6.3 Defense against infectious disease. Read pp._________, EBQ #________, HW due dates_________, Quiz date______ Assessment statement Obj Clarifying notes 6.3.1 Define pathogen. 1 Pathogen: an organism or virus that causes a disease. 6.3.2 Explain why antibiotics are effective against bacteria but not against viruses. 3 Antibiotics specific metabolic pathways found in bacteria. Viruses reproduce
using the host cell’s metabolic pathways, which are not affected by antibiotics. Aim 8: The great benefits to people throughout the world in the control of bacterial diseases using antibiotics should be stressed. Examples of diseases that often proved fatal before the advent of antibiotics could be named. 6.3.3 Outline the role of skin and mucous membranes in defense against pathogens. 2 A diagram of the skin is not required. 6.3.4 Outline how phagocytic leucocytes ingest pathogens in the and in body tissues. 2 Details of the subdivisions and classifications of phagocytes are not required. 6.3.5 Distinguish between antigens and antibodies. 2 6.3.6 Explain antibody production. 3 Many different types of lymphocyte exist. Each type recognizes one specific