7th Grade S2 Reg.Adv S2 Content Review Guide_Student Answer Key PDF

Hillsborough County Public Schools-Answer Key Middle School Science Grade 7 NOS in Life Science M/J Comp Sci 2 Adv & Reg Semester 2 Content Review Nature of Science Standards SC.8.N.1.1 Define a problem from the eighth grade curriculum: use appropriate reference materials to support scientific under...

Hillsborough County Public Schools-Answer Key Middle School Science Grade 7 NOS in Life Science M/J Comp Sci 2 Adv & Reg Semester 2 Content Review Nature of Science Standards SC.8.N.1.1 Define a problem from the eighth grade curriculum: use appropriate reference materials to support scientific understanding; plan and carry out scientific investigations of various types, such as systematic observations or experiments; identify variables; collect and organize data; interpret data in charts, tables, and graphics; analyze information; make predictions; and defend conclusions. SC.7.N.1.2 Differentiate replication (by others) from repetition (multiple trials). SC.7.N.1.3 Distinguish between an experiment (which must involve the identification and control of variables) and other forms of scientific investigation and explain that not all scientific knowledge is derived from experimentation. SC.8.N.1.3 Use phrases such as results support or fail to support in science, understanding that science does not offer conclusive “proof” of a knowledge claim. SC.7.N.1.4 Identify test variables (independent variables) and outcome variables (dependent variables) in an experiment. SC.7.N.1.5 Describe the methods used in the pursuit of a scientific explanation as seen in different fields of science such as biology, geology, and physics. SC.8.N.1.5 Analyze the methods used to develop a scientific explanation as seen in different fields of science. SC.8.N.1.6 Understand that scientific investigations involve the collection of relevant empirical evidence; the use of logical reasoning; and the application of imagination in devising hypotheses, predictions, explanations, and models to make sense of the collected evidence. SC.7.N.1.7 Explain that scientific knowledge is the result of a great deal of debate and confirmation within the science community. SC.7.N.2.1 Identify an instance from the history of science in which scientific knowledge has changed when new evidence or new interpretations are encountered. SC.6.N.3.1 Recognize and explain that a scientific theory is a well-supported and widely accepted explanation of nature and is not simply a claim posed by an individual. Thus, the use of the term theory in science is very different than how it is used in everyday life. SC.7.N.3.1 Recognize and explain the difference between theories and laws and give several examples of scientific theories and the evidence that supports them. SC.6.N.3.2 Recognize and explain that a scientific law is a description of a specific relationship under given conditions in the natural world. Thus, scientific laws are different from societal laws. SC.7.N.3.2 Identify the benefits and limitations of the use of scientific models. 1. Pet stores sell meal worms as food so it is important that they are fed well so the supply does not dwindle. If a pet store wanted to identify the preferred type of food for mealworms what might their investigation look like? 1. They would need to formulate a hypothesis for a type of food they think is preferred. 2. They would need to identify the variables (Independent: Types of food, Dependent: how much food is eaten/preferred) 3. Collect the data in a controlled environment 4. Communicate the results and revise the hypothesis if needed. 2. Based on the data in the diagram below, what would an appropriate conclusion be? The rabbit and wolf populations are inversely related. As the rabbit population decreases the wolf population increases. This may also indicate that the rabbits are a food source for the wolves. 3. Differentiate between replication and repetition. (Pearson page 340) Replication is when another scientist repeats the same experiment that another first did. Repeition is when there are multiple trials of the same experiment done by the same scientist. 4. Gregor thinks that anthills are wider when the ground is muddy. He created the table below. Is his investigation a scientific experiment? (Pearson page 341-342) His investigation is not a scientific experiment because he does not test and control variables. 5. Students hypothesize that temperature is a limiting factor for the germination of seeds. They carry out an experiment to test their hypothesis. They label two plastic bags A and B and place a damp paper towel and one bean seed in each bag. They place one bag in a lighted refrigerator and the other bag on the windowsill. Whenever the paper towels look dry, they add more water. Each day they check to see if the seeds have germinated and record their observations in a data table. Which of the following is the dependent variable in this experiment? Length 6. A biologist studies living or once-living organisms. When a biologist thinks he has discovered a new plant, he classifies it. What method is he most likely to use to in his pursuit of scientific explanation? He compares traits to other plants he knows. 7. How is scientific knowledge gained and accepted by the scientific community? (Pearson page 343) Scientists contribute to scientific knowledge by conducting investigations and drawing conclusions. They also do this by questioning and confirming each other’s work. Any conclusion or scientific explanation, even one drawn from empirical evidence, is likely to be questioned or challenged. When scientists debate, they discuss ideas with the goal of advancing scientific knowledge. A great deal of debate occurs among scientists, not to bring about conflict, but to make sure all scientific explanations are based on solid evidence. Confirmation involves proving results are true through replication. Even a conclusion based on a simple controlled experiment might be challenged if other scientists replicate the study and obtain different results or identify a flaw in the original experiment. 8. Identify the benefits and limitations of the food web model below: (Pearson page 262, 345). Benefits: Shows the energy transfer between organisms, shows relationships in a large ecosystem Limitations: Does not account for outsie factors, not to scale (Size and quantity of consumption) 9. Why is the evolution a theory and not a law? It provides an evidence-based explanation for why and how evolution takes place. Life Science Standards SC.7.L.15.1 Recognize that fossil evidence is consistent with the scientific theory of evolution that living things evolved from earlier species. SC.7.L.15.2 Explore the scientific theory of evolution by recognizing and explaining ways in which genetic variation and environmental factors contribute to evolution by natural selection and diversity of organisms. SC.7.L.15.3 Explore the scientific theory of evolution by relating how the inability of a species to adapt within a changing environment may contribute to the extinction of that species. SC.7.L.16.1 Understand and explain that every organism requires a set of instructions that specifies its traits, that this hereditary information (DNA) contains genes located in the chromosomes of each cell, and that heredity is the passage of these instructions from one generation to another. SC.7.L.16.2 Determine the probabilities for genotype and phenotype combinations using Punnett Squares and pedigrees SC.7.L.16.3 Compare and contrast the general processes of sexual reproduction requiring meiosis and asexual reproduction requiring mitosis SC.7.L.16.4 Recognize and explore the impact of biotechnology (cloning, genetic engineering, artificial selection) on the individual, society and the environment SC.7.L.17.1 Explain and illustrate the roles of and relationships among producers, consumers, and decomposers in the process of energy transfer in a food web. SC.7.L.17.2 Compare and contrast the relationships among organisms such as mutualism, predation, parasitism, competition, and commensalism. SC.7.L.17.3 Describe and investigate various limiting factors in the local ecosystem and their impact on native populations, including food, shelter, water, space, disease, parasitism, predation, and nesting sites. SC.8.L.18.3 Construct a scientific model of the carbon cycle to show how matter and energy are continuously transferred within and between organisms and their physical environment. SC.8.L.18.4 Cite evidence that living systems follow the Laws of Conservation of Mass and Energy. 10. How does the fossil record show evidence of evolution in the horse as shown in the diagram below? (Pearson pages 216-217). There is a fossil record of most of the horse ancestors. Most of what we know about ancient organisms comes from the fossil record. The fossil record provides evidence about the history of life and past environments on Earth. The fossil record also shows how different groups of organisms have changed over time. Each new discovery helps to fill holes in our understanding of evolution. 11. How did Charles Darwin learn that genetic variation of traits allow organisms to survive in their environment? (Pearson page 198) Darwin observed that some variations make individuals better adapted to their environment. Those individuals were more likely to survive and reproduce, and their offspring would inherit the helpful characteristic. The offspring, in turn, would be more likely to survive and reproduce and pass the characteristic to their offspring. After many generations, more members of the population would have the helpful characteristic resulting in natural selection. 12. Tasmanian tigers were large mammals that lived in Australia, but as more people hunted the tiger it became rare. The last captive Tasmanian tiger died in the 1960s and no wild Tasmanian tigers have been seen for decades. If there are any remaining Tasmanian tigers, their population is very small. Most biologists assume the Tasmanian tiger is extinct. How could a scientist justify the decision to declare the Tasmanian tiger extinct? (Pearson Page 220) When populations are very small, it is hard for a population to retain the genetic diversity required to adapt to a changing environment thus they become extinct. 13. Genes, chromosomes, and DNA are important structures for processes related to heredity and reproduction. How are these three structures related? (Pearson page 153) Genes are sections of DNA that make up a chromosome. 14. What is the difference between genotype and phenotype? (Pearson page 138) Genotype is the genetic makeup (letters) and phenotype is the appearance (what it looks like) 15. In a species of mice, fur color can either be brown (B) or white (b). The allele for brown fur is dominant, and the allele for white fur is recessive. The pedigree shows the inheritance of fur color through three generations of mice. What is the genotype and phenotype of individual 1? (Pearson page 141) She has a white fur phenotype and a genotype of bb. 16. In a certain type of plant the allele for purple flowers (P) is dominant, while the allele for pink flowers (p) is recessive. Plant 1 and Plant 2 and both heterozygous for the color of their flowers. What are the colors of the flowers on the parent plants and what is the probability that the plants will produce pink offspring? Use the Punnett square to answer the question. (Pearson pages 136-137 and page 133) The parents have purple flowers. The probability that their offspring will have pink flowers is 25%. 17. The genes associated with flower color correspond to F= Red and f= white. If a parent has an offspring that is white, what must their genotype be? (Pearson pages 136-137) The offspring’s genotype must be ff. 18. How are co-dominance and multiple alleles expressed? And give examples. (Person pages 125-126) Codominance: Unlike incomplete dominance, which shows blending of traits, codominance results in both alleles being expressed at the same time. In cattle, horses, and dogs, there is a color pattern called roan. This color pattern appears when a dominant white-hair allele and a dominant solid-color allele is inherited. The offspring has hairs of each color intermixed, giving the solid-color a more muted or mottled look. Multiple Alleles: Every offspring inherits one allele from each parent for a total of two alleles. However, sometimes one trait has more than two alleles. For example, there are three alleles for blood type—A, B, and O. The A and B blood types are co-dominant and O is recessive. 19. How would you describe the process of sexual reproduction? How does the DNA of offspring compare to that of the parents? (Pearson page 122) In sexual reproduction, two parents combine their genetic material to produce a new organism which differs from both parents. Sexual reproduction involves an egg cell and a sperm cell joining to form a new cell in a process called fertilization. Sperm cells are from the father and contain half of the father’s chromosomes. Egg cells are from the mother and contain half the mother’s chromosomes. When fertilization occurs, a full set of chromosomes is present in the new cell. Because offspring receive roughly half their genetic information from each parent, they receive a combination of specific characteristics. A specific characteristic that an organism can pass to its offspring through its genes is called a trait. A gene is a sequence of DNA that determines a trait and is passed from parent to offspring. As a result, offspring may look very similar to their parents, or they may look very different. These differences are known as variations, and they are what make you different from your siblings. Individual variations depend on which genes were passed on from each parent. 20. What is the difference between asexual and sexual reproduction in organisms? (Pearson pages 121-122) Asexual Reproduction: A reproductive process that involves only one parent and produces offspring that are genetically identical to the parent is called asexual reproduction. Sexual reproduction: In sexual reproduction, two parents combine their genetic material to produce a new organism which differs from both parents. Sexual reproduction involves an egg cell and a sperm cell joining to form a new cell in a process called fertilization. 21. Describe the main difference between the processes of meiosis and mitosis. (Pearson page 149) Mitosis is a process of asexual reproduction and meiosis is a process of sexual reproduction. 22. What are some advantages of sexual reproduction? (Pearson page 197) Sexual reproduction allows for more genetic variation. This could continue to help organisms evolve over time (natural selection) for traits that are more valued. 23. What are the advantages and disadvantages of genetically modified organisms (GMOs)? (Pearson page 170) GMOs are made by changing the original DNA so desired traits are expressed. Growing our food from seeds that have been genetically modified is highly controversial. Many people fear the impact it could have on human health and the environment in the future. Yet farmers are able to yield more product with GMO crops that are not eaten by pests or overcome by weeds. Scientists must balance sustaining a growing human population with safeguarding the environment. 24. How are clones produced? What is the genetic similarity between the organism that was produced from that of the original organism? (Pearson page 167) A clone is an exact genetic copy of the parent. 25. Identify and describe the roles of each organism in the food web below: (Pearson page 262). Sun: Producer Plant: Producer that provides energy to the other consumers Grasshopper: Primary consumer that gains energy from the plant and provides energy to other high level consumers Mouse: Secondary Consumer that gains energy from the plant and the grass hopper and provides energy to the snake and hawk Snake: Tertiary Consumer that gains energy from the mouse and provides energy to the hawk Hawk: Quaranery Consumer that gains energy from both the sname and the mouse Use the diagram below to answer questions 26 and 27 26. Which organisms are competing? (Pearson page 271-275) The snake and the owl because they both eat frogs. 27. If a crab were added to this food web, and it ate the scraps left behind by the frog, what would best describe the relationship between the crab and the frog? (Pearson page 271-275) Commensalism because the crab would benefit from the frogs scraps and the frog will not be affected by the crab in a positive or negative way. 28. A tiger shark rises to the surface of the ocean and grans a sea snake swimming on the surface. How would you describe this relationship? (Pearson page 272). An interaction in which one organism kills another for food or nutrients is called predation. In this interaction, one organism is the predator (tiger shark) and the other is the prey (sea snake). 29. Goby fish live in close proximity to many other water animals. They often lay their eggs in burrows built by blind pistol shrimp. The blind pistol shrimp have feelers that sense when the goby fish flee nearby predators. Some goby fish eat the parasites of other, larger predator fish. Based on the information provided, what would be considered a limiting factor in the goby fish’s ecosystem? (Pearson page 254) An environmental factor that causes a population to stop growing or to decrease in size, such as a fatal disease infecting organisms, organisms, is a limiting factor. In this example the number of pistol shrimp because goby fish often lay their eggs in shrimp burrows. Other limiting factors in ecosystems include: Food, water, climate and weather, space and shelter. 30. How is the law of conservation of mass and energy illustrated in the food chain below? (Pearson pages 262 and 319) The Law of In the example above, the Osprey eventually gets its energy from the sun via the transfer of energy to plants, shrimp, minnow, perch, pike and finally Osprey. In the law of Conservation of energy and mass, the suns energy travels up the chain, though some of the energy is also lost as heat. 31.What is the role of process C in the Carbon Cycle Diagram below? (Pearson T6) The horse releases carbon dioxide as a byproduct of cellular respiration. 32. Forest fires are part of the life cycle of Yellowstone National Park. They are an important part of the biogeochemical cycles that move matter from one sphere of Earth to another. Biogeochemical cycles are evidence that the biosphere follows the law of conservation of mass. Based on the diagram, what happened to the matter that made up the needles of the trees that are burning? Mass is conserved as it became smoke, ash, and gases.