Unit 4: Energy, Environment, Microbiology and Immunity
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Topic 5 - Energy Flow, Ecosystems and the Environment
5.1Overall reaction of photosynthesis
Understand the overall reaction of photosynthesis as requiring energy from light to split apart the strong bonds in water molecules, storing the hydrogen in a fuel (glucose) by combining it with carbon dioxide and releasing oxygen into the atmosphere
5.2Photophosphorylation, ATP and energy supply
Understand how photophosphorylation of ADP requires energy and that hydrolysis of ATP provides an immediate supply of energy for biological processes
5.3Light-dependent reactions
Understand the light-dependent reactions of photosynthesis, including how light energy is trapped by exciting electrons in chlorophyll and the role of these electrons in generating ATP, reducing NADP in cyclic and non-cyclic photophosphorylation and producing oxygen through photolysis of water
5.4Light-independent reactions and Calvin cycle products
(i) understand the light-independent reactions as reduction of carbon dioxide using the products of the light-dependent reactions (carbon fixation in the Calvin cycle, the role of GP, GALP, RuBP and RUBISCO) (ii) know that the products are simple sugars that are used by plants, animals and other organisms in respiration and the synthesis of new biological molecules (polysaccharides, amino acids, proteins, lipids and nucleic acids)
5.5Chloroplast structure and photosynthesis
Understand the structure of chloroplasts in relation to their role in photosynthesis
5.6Absorption and action spectra
Understand what is meant by the terms absorption spectrum and action spectrum
5.7Chloroplast pigment chromatography
Understand that chloroplast pigments can be separated using chromatography and the pigments identified using Rf values
5.8Core Practical 10 - factors affecting photosynthesis rate
CORE PRACTICAL 10 Investigate the effects of light intensity, light wavelength, temperature and availability of carbon dioxide on the rate of photosynthesis using a suitable aquatic plant.
5.9GPP, NPP and plant respiration
(i) understand the relationship between gross primary productivity (GPP), net primary productivity (NPP) and plant respiration (R) (ii) be able to calculate net primary productivity
5.10Biomass and energy transfer efficiency
Know how to calculate the efficiency of biomass and energy transfers between trophic levels
5.11Population, community, habitat and ecosystem
Understand what is meant by the terms population, community, habitat and ecosystem
5.12Biotic and abiotic factors
Understand that the numbers and distribution of organisms in a habitat are controlled by biotic and abiotic factors
5.13Niche, distribution and abundance
Understand how the concept of niche accounts for the distribution and abundance of organisms in a habitat
5.14Core Practical 11 - habitat ecology study
CORE PRACTICAL 11 Carry out a study of the ecology of a habitat, such as using quadrats and transects to determine the distribution and abundance of organisms, and measuring abiotic factors appropriate to the habitat.
5.15Succession and climax community
Understand the stages of succession from colonisation to the formation of a climax community
5.16Evidence for climate change
Understand the different types of evidence for climate change and its causes, including records of carbon dioxide levels, temperature records, pollen in peat bogs and dendrochronology, recognising correlations and causal relationships
5.17Anthropogenic climate change and greenhouse gases
Understand the causes of anthropogenic climate change, including the role of greenhouse gases in the greenhouse effect
5.18Carbon cycle applications
Understand how knowledge of the carbon cycle can be applied to methods to reduce atmospheric levels of carbon dioxide
5.19Climate models and extrapolation
(i) understand that data can be extrapolated to make predictions and that these are used in models of future climate change (ii) understand that models for climate change have limitations
5.20Climate change effects on plants and animals
Understand the effects of climate change (changing rainfall patterns and changes in seasonal cycles) on plants and animals (distribution of species, development and lifecycles)
5.21Temperature, enzyme activity and Q10
Understand the effect of temperature on the rate of enzyme activity and its impact on plants, animals and microorganisms, to include Q10
5.22Core Practical 12 - temperature and organism development
CORE PRACTICAL 12 Investigate the effects of temperature on the development of organisms (such as seedling growth rate or brine shrimp hatch rates), taking into account the ethical use of organisms.
5.23Evolution by mutation and natural selection
Understand how evolution (a change in allele frequency) can come about through gene mutation and natural selection
5.24Isolation, gene flow and speciation
Understand how isolation reduces gene flow between populations, leading to allopatric or sympatric speciation
5.25Scientific conclusions in controversial issues
Understand the way in which scientific conclusions about controversial issues, such as what actions should be taken to reduce climate change, or the degree to which humans are affecting climate change, can sometimes depend on who is reaching the conclusions
5.26Conservation management and human needs
Understand how reforestation and the use of sustainable resources, including biofuels, are examples of the effective management of the conflict between human needs and conservation
Topic 6 - Microbiology, Immunity and Forensics
6.1Culturing microorganisms and aseptic technique
Understand the principles and techniques involved in culturing microorganisms, using aseptic technique
6.2Measuring microorganism growth
Understand the different methods of measuring the growth of microorganisms, as illustrated by cell counts, dilution plating, mass and optical methods (turbidity)
6.3Bacterial growth curves and growth rate constants
Understand the different phases of a bacterial growth curve (lag phase, exponential phase, stationary phase and death phase) and be able to calculate exponential growth rate constants
6.4Core Practical 13 - microorganism growth rate
CORE PRACTIAL 13 Investigate the rate of growth of microorganisms in a liquid culture, taking into account the safe and ethical use of organisms.
6.5Bacteria, viruses, lytic cycle and latency
(i) be able to compare the structure of bacteria and viruses (nucleic acid, capsid structure and envelope) with reference to Ebola virus, tobacco mosaic virus (TMV), human immunodeficiency virus (HIV) and lambda phage (λ phage) (ii) understand what is meant by the terms lytic and latency
6.6Mycobacterium tuberculosis and HIV infection
Understand how Mycobacterium tuberculosis and human immunodeficiency virus (HIV) infect human cells, causing symptoms that may result in death
6.7Pathogen entry routes and barriers
(i) know the major routes pathogens may take when entering the body (ii) understand the role of barriers in protecting the body from infection, including skin, stomach acid, and gut and skin flora
6.8Non-specific responses to infection
Understand the non-specific responses of the body to infection, including inflammation, lysozyme action, interferon and phagocytosis
6.9Antigens, antibodies and immune response
Understand the roles of antigens and antibodies in the body’s immune response including the involvement of plasma cells, macrophages and antigen-presenting cells
6.10B cells and T cells
Understand the differences between the roles of B cells (B memory and B effector cells), and T cells (T helper, T killer and T memory cells) in the host’s immune response
6.11Natural, artificial, active and passive immunity
Understand how individuals may develop immunity (natural, artificial, active and passive)
6.12Evolutionary race between pathogens and hosts
Understand how the theory of an ‘evolutionary race’ between pathogens and their hosts is supported by evasion mechanisms shown by pathogens
6.13Bacteriostatic and bactericidal antibiotics
Understand the difference between bacteriostatic and bactericidal antibiotics
6.14Core Practical 14 - antibiotics and bacteria
CORE PRACTICAL 14 Investigate the effect of different antibiotics on bacteria.
6.15Hospital-acquired infections and practice codes
Know how an understanding of the contributory causes of hospital-acquired infections has led to codes of practice regarding antibiotic prescription and hospital practice that relate to infection prevention and control
6.16Microorganisms in decomposition and carbon recycling
Know the role of microorganisms in the decomposition of organic matter and the recycling of carbon
6.17PCR amplification of DNA
Know how DNA can be amplified using the polymerase chain reaction (PCR)
6.18Gel electrophoresis of DNA fragments
Know how gel electrophoresis can be used to separate DNA fragments of different length
6.19DNA profiling
Understand how DNA profiling is used for identification and determining genetic relationships between organisms (plants and animals)
6.20Determining time of death
Understand how to determine the time of death of a mammal by examining the extent of decomposition, stage of succession, forensic entomology, body temperature and degree of muscle contraction