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LO 2.3 The student is able to predict how changes in free energy availability affect organisms, populations and ecosystems. SP 6.4 The student can make.

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Presentation on theme: "LO 2.3 The student is able to predict how changes in free energy availability affect organisms, populations and ecosystems. SP 6.4 The student can make."— Presentation transcript:

1 LO 2.3 The student is able to predict how changes in free energy availability affect organisms, populations and ecosystems. SP 6.4 The student can make claims and predictions about natural phenomena based on scientific theories and models. ● Explanation: Free energy can be captured many different ways depending on the organism. A photosynthetic organism gets free energy by using the sun. A chemosynthetic gets energy by small inorganic molecules in the environment. Heterotrophs obtain free energy by using other organisms carbon compounds. In eukaryotes cellular respiration captures free energy this includes the processes of : The Krebs Cycle, Glycolysis, and the electron transport chain. The ten percent rule is when the free energy moves through a food chain only 10 percent of the energy is actually passed to the next organism. Thus meaning the top of the food chain must be the smallest because there would not be enough energy to support the population if there were more predators then prey. Since free energy goes through multiple organisms a change at the bottom of the food chain would affect the rest of the populations and environment as well. Which of the following best explains why energy cannot cycle through an ecosystem? A.The law of conservation of energy B.The second law of thermodynamics C.The competitive exclusion principle D.The green world hypothesis E.The principle of bio magnification Learning Log/ FRQ-style Question: An energy pyramid for a marine ecosystem is shown to the right. Label each trophic level of the pyramid and provide an example of a marine organism found at each level of this pyramid. Explain why the energy available at the top layer of the pyramid is a small percentage of the energy present at the bottom of the pyramid.

2 LO 2.4: The student is able to use representations to pose scientific questions about what mechanisms and structural features allow organisms to capture, store and use free energy. SP: 1.4 The student can use representations and models to analyze situations or solve problems qualitatively and quantitatively. SP: 3.1 The student can pose scientific questions Explanation: In Autotrophs, free energy is captured from the physical sources in the environment. Autotrophic organisms that use photosynthesis capture the free energy present in sunlight, whereas heterotrophic organisms capture free energy present in carbon compounds produced by other organisms. In heterotrophs, storing and use of energy is much more complex because some heterotrophs may metabolize carbohydrates, lipids and proteins by hydrolysis as sources of free energy. In the absence of oxygen, fermentation produces organic molecules in heterotrophs. M.C. Question: An experiment to measure the rate of respiration in crickets and mice at 10°C and 25°C was performed using a respirometer, an apparatus that measures changes in gas volume. Respiration was measured in mL of O2 consumed per gram of organism over several five-minute trials, and the following data were obtained. Organism Temperature (°C) Average respiration (mL O2/g/min) Mouse Mouse Cricket Cricket According to the data, the mice at 10°C demonstrated greater oxygen consumption per gram of tissue than did the mice at 25°C. This is most likely explained by which of the following statements? (A) The mice at 10°C had a higher rate of ATP production than the mice at 25°C. (B) The mice at 10°C had a lower metabolic rate than the mice at 25°C. (C) The mice at 25°C weighed less than the mice at 10°C. (D) The mice at 25°C were more active than the mice at 10°C. FRQ-style Question: The metabolic rates of organisms determines how quickly energy is used up when at rest. Explain why some organisms must constantly consume food to maintain their metabolism and support themselves whereas some organisms can consume a large amount of food at one time and still maintain their metabolism over the course of weeks, such as in hibernation?

3 LO 2.5: The student is able to construct explanations of the mechanisms and structural features of cells that allow organisms to capture, store or use free energy. SP 6.2: The student can construct explanations of phenomena based on evidence produced through scientific practices. Explanation: In plants free energy is captured by chloroplasts with the use of chlorophyll. Chlorophyll absorbs the energy from the light by excited electrons which jump energy levels. The energy stored from this process is used to drive photosynthesis. A process in which water and carbon dioxide are manipulated to produce a sugar that is usable by the plant and oxygen, a bi- product, that is released from the plant. The glucose is then broken down through cellular respiration to produce ATP which the plant uses in various cell processes such as active transport. Active transport is used to pump particles from an area of low concentration to high concentration in order to maintain homeostasis. M.C. Question: If the rubisco coding sequence were to be altered in a plant what process would be inhibited? A.ATP production B.Phosphorylation C.Transcription D.Carbon Fixation Free Response: Describe the process in which plants use energy from the sun to produce complex molecules to be later used in respiration. In your response be sure to include at least 2 adaptations in which plants have evolved to handle photosynthetic problems due to harsh environments that some plants live in as well as an example for each.

4 LO 2.10: The student is able to use representations and models to pose scientific questions about the properties of cell membranes and selective permeability based on molecular structure. SP 1.4: The student can use representations and models to analyze situations or solve problems qualitatively and quantitatively Explanation: A cell’s membrane helps protect the cell from foreign invaders. The membrane of a cell is semi- permeable because of protein channels within the membrane and also because of the membrane’s phospholipid bilayer. The polar hydrophilic head of the phospholipid prevents nonpolar substances from entering the cell. The nonpolar tails on the inside of the lipid bilayer deter smaller substances from entering the cell at harmful rates. Proteins are also embedded into the cell’s membrane for a various amount of reasons. Some proteins are used for cell to cell recognition and others are used as channels to rid the cell of waste or take in nutrients. M.C Question: Which of the following is a typical component in the plasma membrane of a eukaryotic cell? A)DNA B)mRNA C)tRNA D)Cholesterol E)Actin Learning log/ Free Response question: Describe the structure of the cell membrane and how it plays a part in the body’s immune system response.

5 LO 2.11: The student is able to construct models that connect the movement of molecules across membranes with membrane structure and function. Explanation: A membrane is held together primarily by hydrophobic interactions, which are much weaker than covalent bonds. In this Fluid mosaic model, the membrane is a fluid stucture with a “mosaic” of various proteins embedded in or attached to a double layer (bilayer) of phospholipids. Proteins embedded in the membrane can enable the movement of molecules across the membrane in various ways. A)A protein could create a hydrophilic channel across the membrane so that a particular solute can pass. B) Other transport proteins shuttle a substance from one side to the other by changing shape. Some of these can hydrolyze ATP as an energy source to actively pump substances across the membrane. C) A Protein built into the membrane may be an enzyme with its active site exposed to the substances in the adjacent solution. Proteins like these are necessary for cellular function. For example, cells need water to function. However, the membrane is made from hydrophobic lipids and prevents water from entering. The proteins create a hydrophilic channel for water to cross so that the cell can obtain water. A lack of ATP would most directly impact the movement of_______. A)Water through a hydrophilic channel across the membrane. B)Hydrophobic molecules slowly diffusing across the lipid bilayer. C)Na+ through a sodium-potassium pump going against its concentration gradient. D)A solute moving diffusing passively through the membrane with the help of a transport protein. SP 1.1:The student can create representations and models of natural or man-made phenomena and systems in the domain. Suppose a paramecium cell was placed in a hypotonic solution. Describe the process by which water would pass through the hydrophobic plasma membrane. Also, hypothesize how the cell avoids being lysed in the hypotonic solution.

6 LO 2.14: The student is able to use representations and models to describe differences in prokaryotic and eukaryotic cells. SP 1.4: The student can use representations and models to analyze situations or solve problems qualitatively and quantitatively. Explanation: Eukaryotic cells have a true nucleus, bound by a double membrane. Prokaryotic cells have no nucleus. The purpose of the nucleus is to sequester the DNA-related functions of the big eukaryotic cell into a smaller chamber, for the purpose of increased efficiency. This function is unnecessary for the prokaryotic cell, because its much smaller size means that all materials within the cell are relatively close together. The cytoplasm of eukaryotic cells is filled with a large, complex collection of organelles, many of them enclosed in their own membranes; the prokaryotic cell contains no membrane-bound organelles which are independent of the plasma membrane. This is a very significant difference, and the source of the vast majority of the greater complexity of the eukaryotic cell. There is much more space within a eukaryotic cell than within a prokaryotic cell, and many of these structures, like the nucleus, increase the efficiency of functions by confining them within smaller spaces within the huge cell, or with communication and movement within the cell. M..C Question: Some prokaryotic cells receive an extra piece of DNA through a process called conjunction. The DNA is called? A) Granule B) Plasmid C) Nucleiod D) Transformation E) Nucleus Learning Log/FRQ- Style Question: Is there any real evidence that mitochondria and chloroplasts were individual cells? If so, what are some similarities they share?

7 LO 2.15 : The student can justify a claim made about the effect(s) on a biological system at the molecular, physiological or organismal level when given a scenario in which one or more components within a negative regulatory system is altered. SP 6.1: The student can justify claims with evidence. Explanation: A negative feedback loop is a homeostatic control system consisting of a receptor which detects the change, a control center which process the change, an effector which produces a response. In a negative feedback loop a change in a variable is detected causing the control system to counteract the response of the variable. An example of a negative feedback look is the regulation of blood glucose through insulin. The stimulus is the rising blood glucose levels which trigger the pancreas to release insulin. Insulin causes body cells to take up more glucose and causes the liver to take in more glucose to store it as glycogen thus lowering the blood glucose levels. The negative feedback loop caused the onset of a rising blood glucose level to be counteracted by insulin causing the reduction of blood glucose levels. When insulin is not produced properly or in little quantities the body is unable to counteract the rising blood glucose levels causing the levels to continue to rise leading to the diagnosis of diabetes mellitus. Diabetes mellitus is a deficiency of insulin or a decrease response in target cells resulting in high blood glucose. M.C. Question: A distinctive feature of the mechanism of action of insulin and glucagon is? A)The control of blood glucose levels through positive feedback loops. B)The antagonistic effects on blood glucose levels. C)The antagonistic effects on blood calcium levels D)Regulating blood glucose levels through their interactions with the nervous system and potassium. Learning log/FRQ style question: You are a doctor and a patient comes in with the symptoms of diabetes mellitus. You decide to run a glucose tolerance test and have the patient drink a glucose containing solution and then every hour for four hours you check their blood glucose levels. What you the results show if the patient did not have diabetes mellitus? Why? Describe using feedback loops and the relationship between feedback loops and blood glucose.

8 LO 2.16: The student is able to connect how organisms use negative feedback to maintain their internal environments. SP 7.1: The student can connect concepts in and across domain(s) to generalize or extrapolate in and/or across enduring understandings and/or big ideas. M.C. Question: The pancreas stabilizes blood glucose levels by releasing insulin and glucagon, depending on whether blood glucose levels are too high or too low. Which of the following demonstrates a correct example of negative feedback in relation to blood glucose regulation? A)Blood glucose levels rise and the pancreas releases glucagon in order to raise blood glucose levels further B)Blood glucose levels fall and the pancreas releases insulin to lower blood glucose levels further C)Blood glucose levels are homeostatic and the pancreas releases neither hormone D)Blood glucose levels fall and the pancreas releases glucagon in order to raise blood glucose levels E)None of these examples provide a correct example of negative feedback Learning Log/ FRQ-style Question: The human nervous system initiates a hormone pathway to regulate the metabolism. a) EXPLAIN this process and b) DESCRIBE how the process relates to negative feedback. Explanation : Maintenance of an organism’s internal environment is also referred to as homeostasis. Homeostasis incorporates negative feedback in order to function properly. In summary, negative feedback works by 1) detecting a change in a system, 2) producing a product in order to combat the change, and 3) stopping the creation of the product through feedback inhibition, a process where the product stops its own creation. Phosphofructokinase utilizes negative feedback during cellular respiration. Phosphofructokinase is activated by AMP, a substance the cell obtains from ADP. Phosphofructokinase helps glycolysis by synthesizing Fructose 1,6-biphosphate from Fructose-6-phosphate. Some of the Fructose-1, 6-biphosphate turns into ATP, while the rest of it turns into pyruvate. If too much ATP is created at this step of glycolysis, it will inhibit phosphofructokinase, thus slowing the production of Fructose-1,6-biphosphate, which will in turn slow ATP production. Phosphofructokinase is also inhibited by citrate, a product of the citric acid cycle. Citrate inhibits phosphofructokinase, which slows production of Fructose-1, 6-biphosphate, part of which is converted to pyruvate (a necessary ingredient for the citric acid cycle). Phosphofructokinase uses negative feedback not only to regulate glycolysis by limiting ATP production directly, but also by limiting the amount of pyruvate that can be synthesized for the citric acid cycle.

9 L.O. 2.17: The student is able to evaluate data that show the effect(s) of changes in concentrations of key molecules on negative feedback mechanisms. S.P. 5.3: The student can evaluate the evidence provided by data sets in relation to a particular scientific question. Explanation: Negative feedback loops are used in many systems in the body. Blood glucose level is one of these systems. If the blood glucose level rose continually, it would cause diabetes and damage the body. To prevent this, blood glucose levels get too high, the pancreas senses that and secretes insulin into the blood stream to lower blood glucose levels. When the blood glucose level gets too low, the pancreas secretes glucagon to raise blood glucose levels. M.C Question: Which of the following demonstrates a negative feedback loop? a)A baby suckling on a mother’s nipple increases the flow of milk. b)An enzyme substrate binding to that enzyme to inhibit the enzyme’s activity. c)An enzyme substrate binding to that enzyme to stimulate the enzyme’s activity. d)The pancreas releasing glucagon to lower the blood glucose level. FRQ/Learning Log Question: Describe 3 negative feedback loops the human body uses, how they are regulated, and what classifies them as negative feedback loops.

10 LO 2.18: The student can make predictions about how organisms use negative feedback mechanisms to maintain their internal environments. SP 6.4: The student can make claims and predictions about natural phenomena based on scientific theories and models. Explanation: Negative Feedback mechanisms within an organism maintain homeostasis by regulating processes found in the body. Operons consist of clusters of genes with related functions that bind to allosteric site of a repressor proteins to shut off transcription at the end of an anabolic pathway. Inducible operons are off but are stimulated when they bind to an inducer, regulatory protein, inactivating it and turning on transcription in catabolic pathways. Thermoregulation occurs in animals to keep the body in a tolerable room temperature; homeostasis. As body temperature rises and proteins denature, causing them to be ineffective, and membranes change, which influences functionality. Plants respond to the lack of water by closing stomata when photosynthesis can not occur to prevent the plant from losing water. M.C. Question: Which of the following is not an example of Negative Feedback? A)Secretion of sweat while playing soccer B)Secretion of insulin to lower blood sugar level C)Contraction during pregnancy D)Secretion of glucagon to increase blood sugar level Learning Log/FRQ-Style Question: Negative Feedback allows homeostasis to be maintained. Explain how the alteration of feedback mechanisms could effect the production of hormones and describe one process in which a negative consequence could affect the homeostasis of the internal environment.

11 LO 2.19: The student is able to make predictions about how positive feedback mechanism amplify activities and processes in organisms based on scientific theories and models. SP 6.4: The student can make claims and predictions about natural phenomena based on scientific theories and models. Explanation: We have learned that in a positive feedback loop a small change causes the organism to keep furthering that change, instead of trying to return to homeostasis as it does in negative feedback loops. Knowing this scientific theory, the student can make accurate predictions about what will happen if told that the onset of contractions in childbirth causes a positive feedback loop (the contractions will keep increasing in amplitude and frequency), or that blood clotting is a positive feedback loop (the initial blood platelets produced will make more and more blood platelets.) These natural phenomena are easy to predict knowing that positive feedback is involved. M.C. Question: Which of the following statements is an accurate prediction of how a positive feedback loop ends? A)It slows down after a while to the point where it is producing reactions at a rate where the body can counter them so the body reaches homeostasis. B) It keeps going because it is always getting triggered by outside stimuli. C) It will eventually reach a point where it produces a counter-signal or there is no more signal to send which suppress the loop. D) The loop abruptly ends after the set amount of reactions have occurred. E) Mr. Mercer sends the Amish to build a log cabin around it so the positive feedback loop can’t move anymore. FRQ-style Question: Name two advantages of positive feedback loops in mammals, and two disadvantages, relating the disadvantages to homeostasis.

12 LO 2.20: The student is able to justify that positive feedback mechanisms amplify responses in organisms. SP 6.1: The student can justify claims with evidence. Explanation: In positive feedback, a variable changes and causes mechanisms to amplify change. Unlike negative feedback, during which a variable causes a response to counteract the initial fluctuation, positive feedback intensifies the initial fluctuation. For example, when a mother is in labor, positive feedback occurs, allowing a baby to force its way headfirst through its mother’s uterus. The pressure of the baby’s head against certain receptors found near the opening of the uterus which stimulates the release of oxytocin causes contractions which then causes more pressure against the uterine opening (cervix) which in turn amplifies the contractions occurring which serves to add more pressure. This builds and builds until, finally, the baby pops out of its mother. Soon after birth, the contractions stop and the positive feedback loop is complete. M.C. Question: Which of the following statements regarding positive feedback is NOT true? A) Stimulation of the mammary gland causing lactation is an example of positive feedback. B) Most hormones are controlled by positive feedback mechanisms that include the pituitary gland. C) Oxytocin is a hormone secreted from the posterior pituitary gland. D) Positive feedback enhances responses to stimuli in an organism. Learning Log/FRQ-style Question: The hormone oxytocin is used to induce abortions. Define the type of feedback mechanism that is used in this process and explain in detail how this hormone would be used to induce abortions.

13 LO 2.21: The student is able to justify the selection of the kind of data needed to answer scientific questions about the relevant mechanism that organism use to respond to changes in their external environment. SP 4.1: The student can justify the selection of the kind of data needed to answer a particular scientific question. Explanation: In order to ensure it’s survival, an organism, or it’s body, will react in ways relevant to the situation or danger, that follows a change or changes in their environment. A common change in one’s external environment, is the change in temperature. Temperature, is a perfect example of a factor, as it diminishes an animal’s body, and affects the activity of enzymes. “Enzymes are biological catalysts or assistants. Enzymes consist of various types of proteins that work to drive the chemical reaction required for a specific action or nutrient. Enzymes can either launch a reaction or speed it up” ( These proteins have what are called optimal conditions, where internal temperature or pH is most suitable for its activity. If the temperature exceeds this limit, the weak bonds that hold the enzyme together, hydrogen bonds, for example, weaken or even break, and the structure is destroyed or denatured, causing the cell to require more energy in chemical processing, and other negative outcomes. In order to prevent this from occurring organism undergo thermoregulation, a mechanism of homeostasis. Homeostasis is defined in the dictionary, as “the tendency of a system, especially the physiological system of higher animals, to maintain internal stability, owing to the coordinated response of its parts to any situation or stimulus that would tend to disturb its normal condition or function.” This maintenance is different for different animals, especially between ectotherms and endotherms, or “cold-blooded' and “warm-blooded” organism. In humans, endothermic,where temperature is optimal between 35 and 40 degrees Celsius, and other animals alike, the stimulus, in this case, heat, causes thermosensitive neurons, to tell the hypothalamus, in the brain, to release a hormone that will cause a chain of events that will result in an action that will attempt to remedy the increase in temperature, and prevent internal temperature from exceeding optimal levels, sweating, for instance. Sweating, cools the body, by being released through glands throughout the body, and evaporating, exchanging heat between the body and environment, making the enzymes work more efficiently, thus the body. One may test aforementioned statement, by setting up a study, in which two people are examined, approximately the same size, one able to sweat normally, the other unable to do so because of some sort of hormonal deficiency, and gathering data, recording and comparing the temperature of the two over a span of time. Confirming whether or not, the thermoregulation effectively cooled the body of the person, thus making the body work more efficiently in more suitable conditions. M.C. Question: A male has a thyroxine deficiency. What would you expect the likely outcome directly resulting of his condition, and what his body would do in order to compensate for the issue, and maintain stability? A) A reduction of blood flow due to vasoconstriction; His body will attempt to increase blood flow, produced by an increase in his heart rate, to prevent heat loss. B) A behavioral change; he will envelope himself in insulating materials, as his body feels cold, and shakes to gain more heat. C) An increase in bodily isolation; to compensate, his body sweats more often to maintain core temperature, and to prevent it from increasing. D) An increased in blood flow, resulting from vasodilation; the body will increase intake or production of Calcium ions to force the body to constrict blood vessels, increasing internal heat. Learning Log/FRQ Style Question: Two organisms live in the same conditions, one is endothermic, a dog, while the other ectothermic, a lizard. The temperature of their environment increases, due to climate change. What you expect the animals to do in order to maintain optimal internal temperature? Will they undergo the same mechanisms and actions under homeostasis? Why? It is said that ectothermic animals save more energy in the attempt to regulate temperature. How is this statement true? Explain.

14 LO 2.22 The student is able to refine scientific models and questions about the effect of complex biotic and abiotic interactions on all biological systems, from cells and organisms to populations, communities and ecosystems. SP 1.3 The student can refine representations and models of natural or man-made phenomena and systems in the domain. SP 3.2 The student can refine scientific questions. Explanation Abiotic factors in an ecosystem are the non-living chemicals or physical components in the environment such as temperature, water, sunlight, wind, and rocks/soil. Temperature because if it is too hot proteins denature, too cold and cells may rupture. Water because global distribution reflects specie ability to save and obtain water. Sunlight due to the fact that it is an energy source used in all ecosystems. Wind amplifies the effects of environmental temperature and rocks/soil because the texture of the soil affect the plants which affects the animals that feed on them. Biotic factors are created by a living thing or any living component within an environment in which the action of the organism(s) affects the life of another, for example a predator (wolf) consuming its prey (deer). These factors directly effect the environment. MC Question Which hypothesis will test the effect of biotic factors on plant growth? A. If the soil is acidic, then plants will not grow well. B. If two kinds of corn seeds are planted, then one will grow better than the other. C. If an insect is placed on a plant, then it might eat the plant. D. If the plants are crowded, then they will not grow well. Learning Log/FRQ-Style Question Give examples of human actions that could expand a species’ distribution by changing its (a) biotic interactions and (b) abiotic factors.

15 LO 2.24: The student is able to analyze data to identify possible patterns and relationships between a biotic or abiotic factor and a biological system. SP 5.1: The student can perform data analysis and evaluation of evidence. Explanation: Various biotic and abiotic factors are able to interact with the environment and with each other. The abiotic factors of the environment include the nonliving components such as the light, temperature, water, and nutrients. They are also identified as being the chemical and physical features of the environment. The biotic factors include the living components of the environment such as the disease, competition, and other species that reside in a particular environment. If any of the abiotic or biotic factors of an environment are changed, it will affect the species that reside there. Combinations of these factors must be considered when explaining patterns of distributions in a biological system. M.C. Question : Which of the following are important abiotic factors that can affect the structure and organization of biological communities? A) nutrient availability, soil pH, light intensity B) precipitation, wind, temperature C) predation, competition, disease D) A and B only E) A, B, and C Learning Log/FRQ Question: Identify and discuss two abiotic factors and two biotic factors that could cause a specific variation of animal populations in a location.

16 Explanation: Homeostatic mechanisms are used by organisms to control internal balance. Examples of these include thermoregulation, gas exchange, digestive mechanisms and osmoregulation. Most organisms share many conserved features that are distributed among organisms today. These processes show each organism is linked together from common ancestry and are conserved through DNA and RNA as carriers. All present life has evolved from this common ancestor. Organisms have various mechanisms for thermoregulation. A divergence along the generations of the common ancestor due to natural selection and adaptation has led to various means of thermoregulation: Endotherms and Ectotherms. These classifications are not mutually exclusive as seen in some birds( which are endotherms) who warm themselves in the sun, but help classify those species that receive temperature regulation through the environment and those that control temperature internally in the countercurrent heat exchange. M.C. Question: The importance of endothermic regulation in mammals is critical to avoid which of the following? A)Increased vasodilation and heat loss through the skin. B)Enzymes that would denature and proteins would not be able to function C)Convection and heat loss with cooling of an organism D)Reduction in heat shock proteins Free Response Question: How do organisms obtain dynamic homeostasis through thermoregulation? Identify 2 specific adaptations that help regulate heat and why this is important to the organism. River otter (endotherm) Largemouth bass (ectotherm) Ambient (environmental) temperature (°C) Body temperature (°C) L.O The student can construct explanations based on scientific evidence that homeostatic mechanisms reflect continuity due to common ancestry and/or divergence due to adaptation in different environments. S.P. 6.2 The student can construct explanations of phenomena based on evidence produced through scientific practices.

17 LO 2.26 The student is able to analyze data to identify phylogenetic patterns or relationships, showing that homeostatic mechanisms reflect both continuity due to common ancestry and change due to evolution in different environments. SP 5.1 The student can analyze data to identify patterns or relationships. Explanation: Over time, organisms have evolved to adapt to their environments and respond to external stimuli. For example, these adaptations have allowed organisms to absorb essential nutrients from their environment and excrete wastes where necessary. At the same time, species that diverge from one another can retain homologous structures that may or may not still be functional, such as the presence similar bone structures in the limbs of humans, bats, and whales. One way of presenting this data in graphical form is a cladogram, where divergent paths can show adaptations and acquired traits. MC Question: In the diagram provided, which of the following conclusions can be made about these organisms? A)Lizards have evolved from birds B)Amphibians and anapsids are equally related to mammals A)Birds and mammals share no common ancestor B)Dinosaurs have the trait of laying amniote eggs C)Amphibians do not classify as “tetrapods” FRQ Question: In the cladogram, explain the relationship between amphibians and synapsid reptiles. What characteristics present on the diagram are shared between these two organisms? Also, suppose that a new fossil was discovered and classified to be a synapsid reptile. This fossil was shown to have wing bone structures, though they are structured very differently from the wings of a bird. These two organisms are the only ones present on the diagram that have wings. How could these structures be classified, and how is it possible that no other organism present has this structure?

18 LO 2.27: the student is able to connect differences in the environment with the evolution of homeostatic mechanisms. SP 7.1: The student can connect phenomena and models across spatial and temporal scales. Explanation: Maintaining homeostasis is important to survival of endothermic animals. The body works by the aid of alot of enzymes. If the internal temperature is higher or lower than the normal, this will effect the the enzymes and therefore stop from working. Homeostasis have to control the temperature of the body so that no enzyme is damaged. Negative feedback (the response is in the opposite direction of the stimulus) is the process by which homeostasis is performed. For example, A drop in core body temperature causes an increase in metabolic rate. The increase in body temperature inhibits the production of thyroid stimulating hormone. Multiple mechanisms regulate the timing and coordination of molecular, physiological and behavioral events that are necessary for an organism’s development and survival, especially the hypothalamus. Physiological responses to toxic substances, dehydration, disruptions to the ecosystem, and Immunological responses to pathogens, toxins and allergens can cause homeostasis to be interrupted. Mammals use specific immune and behavioral responses triggered by natural or artificial agents to restore homeostasis. In order to maintain body temperature, mammals have insulation (hair, fat), circulatory adaption, and evaporative cooling M.C. Question: Which of the following is an example of homeostasis? A) Ectotherms that maintain a constant internal body temperature. B) Endotherms that maintain a constant internal body temperature. C) Lying in the shade to keep cool. D) Producing large amounts of urea. Learning Log/ FRQ-style Question: In cool weather, jackrabbits sometimes flatten their ears against their body. What is an advantage and disadvantage of this behavioral response? List 3 other regulatory mechanisms that the jackrabbit could use to maintain homeostasis/ body temperature. Fig The thermostat function of the Hypothalamus in human thermoregulation

19 Explanation: Homeostasis is most generally defined as a state of balance or equilibrium in the body. It is maintained through internal regulation systems and a series of feedback controls. The purpose of homeostasis is to maintain a stable and constant condition within the body, such as nutritional balance through digestion or water content balance through urination and sweat. Dynamic homeostasis refers to the idea that while the body is in motion it maintains internal environments through biological processes despite the effects of environmental disruptions. Dynamic homeostasis can be observed qualitatively for example, thermoregulation in animals maintain an internal temperature within a tolerable range. An optimal range is the temperatures at which an organism is most effective. Thermoregulation helps keep the body temperature within that optimal range. A quantitative example would be water potential in plants. The water potential is a physical property predicting the direction in which water will flow, governed by solute concentration and applied pressure. Based on the quantitative data of the amount of solute concentration and the negativity that pulls the water up the plant. The dynamic homeostasis is what is trying to balance to solute concentration causing the movement. The balance of homeostasis is dynamic because although there are environmental and internal disruptions, dynamic homeostasis maintains a stable internal environment. MC Question: If a patient is diagnosed with renal failure, they are unable to clean the body of excess minerals, fluids, and wastes. What would be a result of this disruption. A. When the kidneys shut down, oxygen cannot be transported to the heart. B. Because the kidneys are unable to filter and maintain the balance of the fluids and minerals in the body, the body can no longer maintain the homeostatic levels in the body. C. The hormone receptors are signaling to the brain that the ph balance in the body is not at an equilibrium D. A positive feedback mechanism allows the fluid levels to be regulated. Learning Log/FRQ-style Question: Diabetes causes a disruption in the balance blood glucose levels, describe the factors that are being affected, explain why this is a problem in maintaining homeostasis and how it can be treated. LO 2.28: The student is able to use representations or models to analyze quantitatively and qualitatively the effects of disruptions to dynamic homeostasis in biological systems. SP 1.4 : The student can use representations and models to analyze situations or solve problems qualitatively and quantitatively.

20 L.O The student can create representations and models to describe immune responses S.P. 1.1-The student can create representations and models of natural or man- made phenomena and systems in the domain. When an invading antigen enters the body, a complex immunological response occurs, called active immunity (passive immunity is when antibodies are acquired from other sources such as the placenta, breast milk. Vaccinations are also an example of this). The antigen will first be engulfed by phagocytic white blood cells. MHC proteins are responsible for presenting pieces of the inside of the cell on the outer membrane for the rest of the body to “see”.The MHC of the white blood cell with the antigen grabs the antigen fragment and brings it to the outer membrane of the cell. T Cells (grow and mature in the thymus) recognize the antigen presenting cells and release a number of cytokine signals. Upon reception of these signals, thousands of clones of memory T cells are produced as well as thousands of cytotoxic T cells. The cytotoxic T cells roam the body in search of the APC’s. Once they find a target, the cytotoxic T cell binds to the APC and secretes perforin; the perforin then creates pores in the APC which eventually leads to lysis and death of the infected cell. Plasma and memory B cells ( grow and mature in bone marrow) are also alerted from the cytokines released by the helper T cell. B cells produce antibodies, or immunoglobulins, that defend against pathogens and toxins in the extracellular fluid. These antibodies bind to specific epitopes on the antigen and are able to neutralize, capture, precipitate or cause the cell experience apoptosis. Plasma B cells immediately produce immunoglobulins and have a rapid response to the antigen and a short term release to suppress the antigen. Memory B and T cells have long term immunity and are able to circulate throughout the body for a long period of time so the next time the same antigen is detected in the body, response time is very fast so a lot of antibodies are produced and the antigen is not able to take its toll on the body. A patient is admitted to a hospital with tumors rapidly metastasizing in his body almost as if the body could not control it. The patient became ill with the flu while at the hospital as well but managed to fight it off rather quickly. Why was his immune response effective for one and not the other? A) immunoglobulins are attacking the antibodies that target cancerous cells B) the MHC protein is not able to bind with the cancerous antigen fragment C) perforin secreted by the cytotoxic T cells does not effect the cancerous cells D) Both B and C

21 L.O Free Response An antigen is present in the body and antibodies are produced. Describe two ways antibodies assist in the destruction of APC’s. Also, why is the second exposure to an antigen less harmful than the initial exposure?

22 LO 2.30: The student can create representations or models to describe nonspecific immune defenses in plants and animals. SP 1.2: The students can describe representations and models of natural or man-made phenomena and systems in the domain. Explanation: Non-specific immune systems provide immediate defense against infection, and are found in all classes of plant and animal life. When a plant detects a part that is infected, it triggers rapid localized programmed cell death to stop the infection further. In plant infectious parts are generally degraded as they can readily generate those parts unlike vertebrates. Recent information suggest that, recognition of pathogen in plant is done by two type of protein i.e. transmembrane PRRs (pattern recognition proteins) and NB-LRR (nucleotide binding- leucine rich repeat). In animals, the outer layers of the skin are made up of cells which are closely packed and filled with a substance known as keratin. This keratin is tough and not able to be broken in to by bacteria or viruses very easily. Breaks in the skin allow pathogens to enter your body. Other mechanical barriers to infection include various membranes which cover the respiratory, digestive and urinary tracts. These mucosal membranes are structured to allow some things to pass, while blocking the bad organisms. For example, the lining of the respiratory tract contains many tiny cilia, which can be thought of a small hairs. These hairs wave around like small brushes, pushing particles and bacteria out of the lungs and respiratory system. Similarly, your digestive and urinary tracts produce various kinds of saliva, mucus and other secretions which aid in flushing out the invading particles. M.C. Question: Secretions from the skin and mucous membranes also contain antimicrobial proteins. One such protein is… A)Lysozyme-invade microorganisms B)Macrophages-engulf and then digest C)Lysozyme-enzyme that digest the cell walls of bacteria D)Lymphocytes-produces immune respondses Llog/FRQ Question: Histamine is a protein that the immune system uses to help protect the body’s cells against infection. The immune system is the body’s natural defense against illness and infection. If the immune system detects a harmful foreign object, such as bacteria or a virus, it will release histamine into nearby cells. The histamine causes small blood vessels to expand and the surrounding skin to swell. This is known as inflammation. What happens in a cellular level when inflammation happens and when would it be necessary to block the histamine protein?

23 LO 2.33: The student is able to justify scientific claims with scientific evidence to show that timing and coordination of several events are necessary for normal development in an organism and that these events are regulated by multiple mechanisms. SP 6.1: The student can justify claims with evidence. Explanation: Apoptosis, the process of programmed cell death, is necessary for normal development in an organism. The timing of apoptosis is vital within development because it allows for a hazardous cell within your body to eliminate itself. Apoptosis also helps the development of humans when they are still in the mother’s womb, for example, it allows for the full development of hands and feet of a human so they don’t remain webbed. The regulation of apoptosis comes from signaling between ligands and the cell itself. Due to the receptors of the cell specifically binding to a death ligand, the cell can actually start the apoptosis process. The signals must also cause the regulatory proteins to initiate the apoptosis pathway for apoptosis to actually occur. M.C. Question: If a researcher found a treatment to reduce the rate of apoptosis in human cells by blocking the death-ligand signaling, what body function would be least affected by this treatment? A)The removal of ineffective immune system cells B)The formation of body organs within the embryo C)The production of abnormal cells within the body D)The maintenance of the number of cells in adults Learning Log/FRQ-Style Question: Suppose the DNA within a cell in your body mutated and will eventually become cancerous. Describe the process in which your body will take in order to perform apoptosis on that specific cell.

24 L.O. 2.34: The student is able to describe the role of programmed cell death in development and differentiation, the reuse of molecules, and the maintenance of dynamic homeostasis. S.P. 7.1: The student can connect phenomena and models across spatial and temporal scales. Explanation: Programmed cell death, or apoptosis, is seen in embryo development with morphogenesis of fingers and toes. Apoptosis rids the body of webbing between fingers and toes to form elongated extremities. This is an evolutionary feat that shows connections to ancestors that may have used the webbing that is vestigial to us in this day in age. Apoptosis not only functions in the developmental system; it is also seen in the immune system when the body is searched for infected or harmful cells (like cancer cells) and then a killer-T cell releases perforin to make the cell undergo apoptosis and rid the body of the infection it carried. Dynamic homeostasis is achieved in our cells by way of the membrane structures and permeability. Transport proteins on the membrane (like aquaporins for water transport) function as channel proteins to allow only certain substances across the membrane, thus maintaining regulated homeostasis. Homeostasis will make the cell want to move in the way of the concentration gradient with passive transport, rather than to use energy for active transport like diffusion. The diffusion of solutes will achieve equilibrium. Multiple Choice Question: Which of the following statements concerning concentration gradient’s effect on membrane transport activity is false? A)Equilibrium is achieved by solute’s tendency to move from areas of high concentration to areas of low concentration. B)Membranes are universally impermeable. C)Transport proteins act as the beginning of signal transduction pathways. D)None of the above. Learning Log Question:. Explain the importance of apoptosis in the development of multicellular organisms. Provide an example in the human body.

25 L.O. 2.35: The student is able to design a plan for collecting data to support the scientific claim that the timing and coordination of physiological events involve regulation. S.P. 4.2: The student can design a plan for collecting data to answer a particular scientific question. Explanation: The timing and coordination of many physiological events across all species of organisms involve regulation. In plants, phototropism is an essential process that involves the differential regulation of cell growth within the stem of a plant responding to light, as the cells on the shaded side of the plant elongate more-so than the cells on the lighted side, which allows the plant stem to bend toward light. An experiment completed by Fritz Went supported the hypothesis that differential distribution of the plant hormone auxin is the driver of this physiological response. In animals, 24-hour circadian rhythms, hibernation, estivation, and migration are examples of regulated and specifically-timed physiological events. In bacteria, quorum sensing alters expression of genes when bacteria experience a high population density. As a bacterial population increases, a signaling molecule called an inducer is produced and received by adjacent bacterial cells, which in turn stimulates production of more inducer via positive feedback. After significant amounts of inducer are produced, transcription of certain genes is turned on, producing a response. An example of a response that is stimulated in this way includes bioluminescence of bacteria within certain species of deep-sea squid. M.C. Question: Quorum sensing would most likely occur when: A)A bacterium senses the production of cAMP B)Tobacco plants are exposed to sunlight C)Bacteria reach a certain critical concentration D)Predator insects eat herbivorous insects E)Insulin binds to target cells FRQ: Describe the difference between long-day and short-day plants. How can a long-day plant be induced to bloom in the middle of winter?

26 LO 2.38: The students is able to analyze data to support the claim that responses to information and communication affect natural selections. [See SP 5.1] SP 5.1: The student can analyze data to identify patterns or relationships. Explanation: In babies and their mothers, for instance, the mother gives breast milk to the toddler to increase the proper essentials such as protein and other nutrients to strengthen and motivate the baby. Without breast milk, the baby would not be able to function to the best of it’s ability when it s gradually ages to and through adultery. The chances for a spread of a gene in a gene pool are increased through reproduction of its own carrier as well as the support of reproduction of other individuals that are likely to share the same genes as ego. Hamilton’s rule states that altruistic behavior are favored by natural selection if the behaviors they lead to carry higher benefits then costs by genetic relatedness to the person the behavior is being directed to. Therefore the communication is not only important for a child, but the results show that it is more beneficial if the woman breastfeeding an infant is it’s biological mother, which helps instigate the babies behavior in a more positive way. M.C. Question: Which of the following statements is valid as to why the ground squirrel will sacrifice itself to help other squirrels? A) The ground squirrels biological behavior indicates it is trying to attract a female. B) Every group of ground squirrels assigns one squirrel to do so in order to save the young and others. C) The ground squirrel learned a certain behavior in where he would sacrifice himself in order to save his family. D) When a ground squirrel acquires the behavior to sacrifice itself to a predator, the predator typically backs off because of the brave behavior. Learning Log/FRG-style Question: Suppose you have a species where a baby can prosper when being exiled from their biological mother. How can the baby survive? Where will it get the necessities vital for survival?

27 LO 2.39-The student is able to justify scientific claims, using evidence, to describe how timing and coordination of behavioral events in organisms are regulated by several mechanisms. SP 6.1- The student can justify claims with evidence Explanation-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. M.C. Question- When horses hear an unusual noise, they turn their ears toward the sound. This is an example of A. a fixed-action pattern. B. habituation. C. associative learning. D. imprinting. E. kinesis. Free Response Question- Behavior of organisms are influenced by environmental factors. Pick two of the following factors and explain how the, environment affects the behavior and why the behavior increases the survivorship of the organism, for each the two factors. Taxis/Kinesis Migration Courtship The courtship ritual starts with the couple making bobbing motions with there neck, towards each other. They then light touch beaks.

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