Biology Ecology Frameworks
Interactions within biological systems lead to complex properties.
All biological systems, from cells to ecosystems, are composed of parts that interact with each other. When this happens, the resulting interactions enable characteristics not found in the individual parts alone. In other words, "the whole is greater than the sum of its parts," a phenomenon sometimes referred to as "emergent properties." Interactions between populations within communities also lead to complex properties. As environmental conditions change in time and space, the structure of the community changes both physically and biologically, resulting in a mosaic in the landscape (variety or patterns ) in a community. Communities are comprised of different populations of organisms that interact with each other in either negative or positive ways (e.g., competition, parasitism and mutualism); community ecology seeks to understand the manner in which groupings of species are distributed in nature, and how they are influenced by their abiotic environment and species interactions. The physical structure of a community is affected by abiotic factors, such as the depth and flow of water in a stream, and also by the spatial distribution of organisms, such as in the canopy of trees. The mix of species in terms of both the number of individuals and the diversity of species defines the structure of the community. Mathematical or computer models can be used to illustrate and investigate interactions of populations within a community and the effects of environmental impacts on a community. Community change resulting from disturbances sometimes follows a pattern (e.g., succession following a wildfire), and in other cases is random and unpredictable (e.g., founder effect). At the ecosystem level, interactions among living organisms and with their environment result in the movement of matter and energy. Ecosystems include producers, consumers, decomposers and a pool of organic matter, plus the physiochemical environment that provides the living conditions for the biotic components. Matter, but not energy, can be recycled within an ecosystem via biogeochemical cycles. Energy flows through the system and can be converted from one type to another, e.g., energy available in sunlight is converted to chemical bond
Biological systems are affected by disruptions to their dynamic homeostasis.
Describe how disruptions to ecosystems impact the dynamic homeostasis or balance of the ecosystem. Be able to use models or data to quantitatively and qualitatively describe the effects of disruptions to dynamic homeostasis in biological systems. • Invasive and/or eruptive species • Human impact • Hurricanes, floods, earthquakes, volcanoes, fires • Water limitation • Salination
Transmission of information results in changes within and between biological systems.
Evolution operates on genetic information that is passed to subsequent generations. However, transmission of nonheritable information also determines critical roles that influence behavior within and between cells, organisms and populations. These responses are dependent upon or influenced by underlying genetic information, and decoding in many cases is complex and affected by external conditions. For example, biological rhythms, mating behaviors, flowering, animal communications and social structures are dependent on and elicited by external signals and may encompass a range of responses and behaviors. Organ systems have evolved that sense and process external information to facilitate and enhance survival, growth and reproduction in multicellular organisms. These include sensory systems that monitor and detect physical and chemical signals from the environment and other individuals in the population and that influence an animal's well- being. Populations of organisms exist in communities. Individual behavior influences population behavior, and both are the products of information recognition, processing and transmission. Communication among individuals within a population may increase the long-term success of the population. Cooperative behavior within a population provides benefits to the population and to the individuals within the population. Examples of benefits include protection from predators, acquisition of prey and resources, sexual reproduction, recognition of offspring and genetic relatedness, and transmission of learned responses.
All biological systems from cells and organisms to populations, communities and ecosystems are affected by complex biotic and abiotic interactions involving exchange of matter and free energy.
Explain how the following organism activities are affected by interactions with biotic and abiotic factors. [See also 4.A.6] • Symbiosis (mutualism, commensalism, parasitism) • Predator-prey relationships • Water and nutrient availability, temperature, salinity, pH 2. State how each of the following abiotic and biotic interactions affect the stability of populations, communities and ecosystems. [See also 4.A.5, 4.A.6] • Water and nutrient availability • Availability of nesting materials and sites • Food chains and food webs • Species diversity • Population density • Algal blooms
Growth, reproduction and maintenance of the organization of living systems require free energy and matter.
Living systems require energy to maintain order, grow and reproduce. In accordance with the laws of thermodynamics, to offset entropy, energy input must exceed energy lost from and used by an organism to maintain order. Organisms must exchange matter with the environment to grow, reproduce and maintain organization. Water and nutrients are essential for building new molecules. Carbon dioxide moves from the environment to photosynthetic organisms where it is metabolized and incorporated into carbohydrates, proteins, nucleic acids or lipids. Nitrogen is essential for building nucleic acids and proteins; phosphorus is incorporated into nucleic acids, phospholipids, ATP and ADP. In aerobic organisms, oxygen serves as an electron acceptor in energy transformations.
Biological systems utilize free energy and molecular building blocks to grow, to reproduce and to maintain dynamic homeostasis.
Living systems require free energy and matter to maintain order, grow and reproduce. Autotrophic cells capture free energy through photosynthesis and chemosynthesis. Cellular respiration and fermentation harvest free energy from sugars to produce free energy carriers, including ATP. Cells and organisms must exchange matter with the environment. For example, water and nutrients are used in the synthesis of new molecules; carbon moves from the environment to organisms where it is incorporated into carbohydrates, proteins, nucleic acids or fats; and oxygen is necessary for more efficient free energy use in cellular respiration.
Organisms must exchange matter with the environment to grow, reproduce and maintain organization.
Molecules and atoms from the environment are necessary to build new molecules. Demonstrate this by explaining how each of the following occurs. 1. Carbon moves from the environment to organisms where it is used to build carbohydrates, proteins, lipids, or nucleic acids. 2. Nitrogen moves from the environment to organisms where it is used in building proteins and nucleic acids. Phosphorus moves from the environment to organisms where it is used in nucleic acids and certain lipids.
Individuals can act on information and communicate it to others.
Organisms exchange information with each other in response to internal changes and external cues, which can change behavior. 1. Explain how organisms in each of the following exchange information with each other in response to internal changes and external cues, causing a behavior change. • Fight or flight • Predator warnings • Protection of young • Plant-plant interactions due to herbivory • Avoidance responses b. Communication occurs through various mechanisms. 1. Describe the various signal behaviors or cues in each of the following that produce changes in the behavior of other organisms and result in differential reproductive success. • Herbivory responses • Territorial marking in mammals • Coloration in flowers 2. Describe the various visual, audible tactile, electrical, and chemical signals used to indicate dominance, find food, establish territory and ensure reproductive success in each of the following. • Bee dances • Bird songs • Territorial markings • Pack behavior • Herd, flock and schooling behavior • Predator warning • Colony and swarming behavior in insects • Coloration c. Responses to information and communication of information are vital to natural selection and evolution in each of the following. [See also 1.A.2] 1. Explain how natural selection favors the following innate and learned behaviors that increase survival and reproductive fitness. • Parent-offspring interactions • Migration patterns • Courtship and mating behaviors • Foraging in bees and other animals • Avoidance behavior to electrical fences, poisons, traps 2. Explain how each of the following cooperative behaviors tend to increase the fitness of the individual and the survival of the population. • Pack behavior • Heard, flock and schooling • Predator-warning • Colony and swarming in insects
Organisms respond to changes in their external environments.
Organisms respond to changes in their environment through behavioral and physiological mechanisms. To foster student understanding of this concept, instructors can choose an illustrative example such as: • Photoperiodism and phototropism in plants • Hibernation and migration in animals • Taxis and kinesis in animals • Chemotaxis in bacteria, sexual reproduction in fungi • Nocturnal and diurnal activity: circadian rhythms • Shivering and sweating in humans
Organisms use feedback mechanisms to regulate growth and reproduction, and to maintain dynamic homeostasis.
Organisms respond to changes in their internal and external environments through behavioral and physiological mechanisms, such as photoperiodism in plants, hibernation and migration in animals, and shivering and sweating in humans
Many biological processes involved in growth, reproduction and dynamic homeostasis include temporal regulation and coordination.
Physiological events in organisms can involve interactions between environmental stimuli and internal molecular signals; phototropism and photoperiodism in plants and circadian rhythms and seasonal responses in animals are examples. Timing and coordination of behavior are also regulated by several means; individuals can act on information and communicate it to others, and responses to information are vital to natural selection. Examples include behaviors in animals triggered by environmental cues (hibernation, migration and estivation), courtship rituals and other visual displays, and photoperiodism in plants due to changes in critical night length.
Timing and coordination of behavior are regulated by various mechanisms and are important in natural selection.
Support the following claims using data or evidence that responses to information and communication of information affect natural selection. [See also 2.C.3] • Innate behaviors are behaviors that are inherited • Learning occurs through interactions with the environment and other organisms • Phototropism in plants responses to changes in light intensity results in differential growth, resulting in maximum exposure of leaves to sunlight. • In phototropism in plants, changes in the length of night regulate flowering and preparation for winter. c. Discuss the mechanisms by which each of the following are triggered by environmental cues and why they are important to reproduction, natural selection and survival. • Hibernation • Estivation • Migration • Courtship d. How do the following cooperative behaviors contribute to the survival of the populations? • Niche and resource partitioning • Mutualistic relationships (lichens, intestinal bacteria, mycorrhizae) • Animal borne pollination
Timing and coordination of physiological events are regulated by multiple mechanisms.
a. In plants, physiological events involve interactions between environmental stimuli and internal molecular signals. [See also 2.C.3] Evidence of student learning is a demonstrated understanding of each of the following: 1. Phototropism, or the response to the presence of light 2. Photoperiodism, or the response to change in length of the night, that results in flowering in long-day and short-day plants b. In animals, internal and external signals regulate a variety of physiological responses that synchronize with environmental cycles and cues. To foster student understanding of this concept, instructors can choose an illustrative example such as: • Circadian rhythms, or the physiological cycle of about 24 hours that is present in all eukaryotes and persists even in the absence of external cues • Diurnal/nocturnal and sleep/awake cycles • Jet lag in humans • Seasonal responses, such as hibernation, estivation and migration • Release and reaction to pheromones • Visual displays in the reproductive cycle c. In fungi, protists and bacteria, internal and external signals regulate a variety of physiological responses that synchronize with environmental cycles and cues Examples include • Fruiting body formation in fungi, slime molds and certain type of bacteria • Quorum sensing in bacteria 1. Justify each scientific claim below with evidence showing how timing and coordination of physiological events involve regulation. • Circadian rhythms • Diurnal/nocturnal and sleep/wake cycles • Jet lag in humans • Seasonal responses such as hibernation, estivation and migration • Release and reaction to pheromones • Visual displays in the reproductive cycle
