The Common Ground Curriculum Science: Biology
CGC Science : Biology Defining Biology: Biology is the study of living things in their environment. This is not a static, snapshot of the living world but an understanding of the past, present and possible future of the biosphere where the major certainty is change. Since dynamic change is central to the modern study of biology we have identified two key questions for biologists: How do individual living things respond to changes in their environment? How do populations of living things change over time? Key Concepts: Organisms Biological Information Genetics Variation Populations Environment Connecting Concepts: Adaptation Energy Materials Structures Interdependence Survival Stresses Species Homeostasis Health Sustainability Processes Inheritance Systems Reactions Growth Change Evolution Reproduction
Conceptual standard 1: Biology of the individual Learners understand that organisms are adapted physically and biochemically to collect and manage energy and raw materials to grow and repair their internal structures. Living things collect energy from their environment and use it to drive key life processes. Green plants collect energy in the form of sunlight thorough photosynthesis and use this to manufacture organic material from carbon dioxide and water. Animals consume organic matter as a source of energy and raw materials for growth. The breakdown of organic material to produce energy occurs in both plants and animals and is called respiration. Living things take in raw materials and process these through a range of reactions collectively known as metabolism. Catabolic reactions breakdown complex organic matter into simpler substances which can be recombined into novel substances through a complex of anabolic reactions. The exact balance of these reactions depends on environmental (energy and material supply, environmental stresses) and internal factors (developmental stage and energy needs). Living things excrete waste products generated by these processes. The living machine Learners understand that living things have complex internal structures and systems that allow energy and materials to be processed efficiently. These internal systems show physical adaptations and change in response to external and internal factors affecting survival. Life processes Learners understand that life processes are common to all living things (movement, respiration, growth, sensitivity, reproduction, excretion, nutrition) and that living things possess physical and chemical adaptations, some of which are characteristic of the individual species, to perform these functions efficiently. Survival needs Learners understand that every living thing makes a range of demands on the environment for survival and some of these may be specific to a particular species or individual. Early childhood Caring for living things Learners understand that living things need a range of things from the environment to survive and grow including factors such as food, air, water and shelter. They will understand these most clearly in terms of food and water for familiar animals like pets.
Conceptual standard 2: Biological information systems Learners understand that organisms manage information flow internally and between themselves and their environment in order to manage the impact of the environment on them and their responses, both short and long-term, to it to ensure continued survival. Living organisms detect changes in their environment (stimuli) through a range of senses. This information can produce responses in terms of growth or development or, in the case of many animals, movement. Many animals have a complex nervous system for processing this information and producing a suitable, rapid response - which may be changed over time by learning. Plant responses tend to be developmental (e.g. flowering, leaf moult) or growth-related (hydrotropism, geotropism) but can be relatively fast (closure of stomata, opening and closing of flowers). Multicellular organisms also monitor their internal environment and produce responses to endogenous stimuli through hormones or direct nerve stimulation or inhibition of organs. Managing internal processes Learners understand that living things monitor their internal as well as their external environments and manage the processes that create and modify their internal environment to keep key factors within the narrow limits necessary for health. Making sense of the world Learners understand that senses provide animals within information that enables them to respond appropriately to ensure their continued survival and that the capabilities of these senses reflect their lifestyle and environmental niche. Responses to the environment Learners understand that living organisms respond to changes in their environment in terms of behaviour or physical development that increase their chances of survival. Early childhood Our five senses Learners understand that our senses tell us things about the world around us and allow us to make decisions that protect our health and well-being
Conceptual standard 3: Genetics and inheritance Learners understand that organisms have systems that transfer information from generation to generation. These mechanisms can result in changes in species that persist for generations. The genome is a store of information chemically coded in the nucleic acids DNA or RNA. This information directs the manufacture of enzymes and, consequently, other cell structures. Other factors (environmental and internal) can modify the expression of this information in real time. A limited number of factors can modify the coded information to introduce random mutations which may be expressed in the next generation. Asexual reproduction tends to conserve the gene assortment whereas sexual reproduction tends to reorganise the genes present in the next generation leading to greater variation. Genetic combinations Learners understand that certain factors are controlled by single genes which allows scientists to predict the proportion of offspring with these characteristics from knowledge of the genotype of the parents. They also understand that factors controlled by multiple genes working in combination cannot be predicted in the same way. The nature of genes Learners understand that genes contain information which allows a newlyfertilised egg to manufacture the body parts needed for an adult organism. They understand that some factors are predominantly controlled by these genes but that others may have a very limited genetic component and be heavily modified by the organism s environment. Parents and offspring Learners understand that both male and female partners contribute characteristics to the offspring but that the offspring is not a simple combination of the two parents. Early childhood Birth and development Learners understand that offspring are the same type of organism as the parents even if the juvenile form of the organism might look very different from the final adult form.
Conceptual standard 4: Variation in populations Learners understand that populations of organisms contain a range of variants and these typically show differential survival when faced with environmental stresses. Over time this can lead to changes in the types of organisms present in an environment and the evolution of novel species. Variation exists within a population of a species. This variation can be heritable or not heritable (produced by the environment and not affecting the germ cells). Heritable variation can be produced by mutation, resorting of genes during gamete production and sexual reproduction. Each variant will respond differently to environmental pressures producing differential survival and contribution to the next generation. This can produce changes in the population of organisms living in an area and in certain circumstances lead to production of a new species. Evolutionary changes Learners understand that environments change and that if populations living in these environments do not have sufficient inherent variation (augmented by random mutations) or the changes are very rapid the population will fail. Where change occurs rapidly enough a new species may develop which replaces the existing population. Natural selection Learners understand that the differences between individuals of a population of organisms of the same species living in an area will mean that some are better equipped to survive in the environment than others leading to an increasingly close match between the characteristics of the environment and the capabilities of the species present. Variation Learners understand that any population of a given species will have a variety of types but that these all belong to the same species and that each species has adaptations that help it to survive in its natural environment.