1 ATTACKING THE SCIENCE TAKSCYPRESS LAKES

2 of the nature of science.OBJECTIVE 1: The student will demonstrate an understanding of the nature of science.

3 Importance of a HypothesisScience is about understanding and explaining nature A hypothesis is our idea about what we think will happen in an experiment. The hypothesis must be testable. The hypothesis is based on things we already know about the subject of our experiment.

4 Hypothesis vs. Theory Theory HypothesisA theory is a general explanation for events that occur in nature. A theory is supported by much data collected from many experiments and observations. Hypothesis A hypothesis is an idea about the outcome of a single experiment. A hypothesis is supported or not supported based on one experiment.

5 Testing a Hypothesis What are you “testing” in the experiment?This is the INDEPENDENT variable (Same as MANIPULATED variable) What effect will you be measuring in your experiment? This is the DEPENDENT variable (Same as RESPONDING variable)

6 Include a Control A control is something with which to compare our experimental results. A control helps us determine that the results were caused by the variables in our experiment. A control may be considered the “normal” conditions.

7 Graphs and Charts

8 Comparison of Car Gas MileageCHARTS Comparison of Car Gas Mileage Title tells what information the chart will provide. Column titles state what the numbers and letters mean. Pay close attention to units used! Units can help identify needed formulas.

9 CHARTS Read the question carefully and see how the chart’s information will help provide the correct answer. Identify key words/phrases that will be useful to interpreting the data. Greenhouse emissions from cars may contribute to global warming. Cars with better gas mileage emit smaller amounts of greenhouse gases. Which car would emit the least amount of greenhouse gases if most of the driving were done on the highway? A J B K C L D M Since higher gas mileage = less greenhouse gases, the car with the highest mileage emits the least amount of greenhouse gases. The questions is asking about highway driving, so ignore the middle column. The answer is B K.

10 GRAPHS From Pure Data  VisualThere are 3 different types of graphs that display data in different ways: Bar graph Line graph Pie/Circle graph Another type of bar graph is a “histogram.” Histogram A bar graph such that the area over each class interval is proportional to the relative frequency of data within this interval.

11 BAR GRAPHS Show data from a one time event that is not continuous; also, the variables do not depend upon one another. What does each “hatch-mark” represent? The Factory is our independent variable since there is no unit of measurement for factories. The dependent variable is simply a one time counting of the number of defects/1,000 cars.

12 LINE GRAPHS Are used to compare variables that are both quantitative, or measured with numbers Show specific values of data, meaning that given one variable the other can easily be determined Show trends in data clearly, meaning that they visibly show how one variable is affected by the other as it increases or decreases. Allow you to predict results of data not yet recorded!

13 LINE GRAPHS This graph shows the trend of a car’s value depending upon the number of miles the car has been driven. Value vs. Mileage Make sure to mention to find an unknown value from a given value, go from the known value on the axis to the line, the from the line to the unknown axis. This number is the unknown value you are looking for.

14 Show data as part of the whole, or asPIE GRAPHS Show data as part of the whole, or as percentages. PIZZA COMPONENTS

15 SAMPLE TAKS QUESTIONS Remind kids to underline key words in the question in order to better understand the charts/graphs. Answer : C 1. Which of the following conclusions is supported by these data? A Alertness is directly related to level of distraction. B Shuffling methods can affect alertness. C Alertness levels vary during the day. D Long periods of rest improve alertness.

16 SAMPLE TAKS QUESTIONS 2. Viruses can be transmitted in a variety of ways. The virus that causes SARS (severe acute respiratory syndrome) can be transmitted when an infected person coughs or sneezes. This virus is transmitted in a manner most similar to the transmission of — A smallpox B AIDS C West Nile virus D influenza Answer : D

17 SAMPLE TAKS QUESTIONS 3. The graph shows data for botulism, a form of food poisoning. The conclusion in the box is based on these data. Which of the following is the best reason this conclusion may be unreliable? A The greatest number of reported botulism cases was 50. B The number of reported botulism cases remained relatively constant from 1988 to 1995. C More botulism cases were reported in the 1980s than in the 1990s. D The number of reported botulism cases decreased after 1994. Answer: D

18 SAMPLE TAKS QUESTIONS 4. A student prepared this graph of tornadoes reported over a 50-year period in a mid-western state. Which statement is supported by these data? A Tornadoes are less frequent in the morning. B Darkness increases the strength of tornadoes. C Tornadoes occurring at night are brief. D The probability of a tornado is the same throughout the day. Answer: A

19 SAMPLE TAKS QUESTIONS Answer: A 5. Protein and dietary fiber are beneficial to health. According to the information in the table, which flour is the most nutritious? A Whole wheat B White wheat C Oat D Rice

20 OBJECTIVE 2: The student will demonstrate an understandingof the organization of living systems.

21 Organization of Living SystemsAtoms Molecules Organelles Cells Tissues Organs Organ Systems Organisms Populations Communities

22 A Closer Look at Cells All living things are composed of one or more cells containing genetic information Cells are the basic unit of all living things Prokaryotic Cells Bacterial Cells – bacteria and archaebacteria Lack Nucleus Lack Membrane-bound organelles Have ribosomes Have genetic material (DNA)

23 Prokaryotic Cell

24 Eukaryotic Cells Cells of Animals, Plants, Fungi, and ProtistsHave a Nucleus (DNA in nucleus) Have Membrane-bound organelles Have Ribosomes

25 Plant Cells

26 Plant Cell Identify the following parts of a plant cell: NucleusNucleolus Chloroplasts Vacuole Mitochondria Cytoplasm Cell Membrane Cell Wall

27 Animal Cell

28 Functions of OrganellesRibosomes Protein Synthesis Mitochondria Energy Production Nucleus Control of Cell Activities Cell Membrane Regulating entry and departure Vacuole Storage

29 Cells Require Energy The ultimate source of energy for living things is the sun. Plant cells can CONVERT the energy of the sun into high-energy organic compounds such as glucose. Glucose can be used to make ATP All cells need ATP to do cell work.

30 Photosynthesis Synthesis of glucoseOccurs in plant cells in chloroplasts Carbon dioxide + Water Glucose + Oxygen 6CO2 + 6H2O C6H12O6 + 6O2 light light

31 Cellular Respiration Process by which cells break down glucose to produce energy Occurs in mitochondria of all eukaryotes Glucose + Oxygen Carbon dioxide + Water Energy C6H12O6 + 6O CO2 + 6H2O + ATP

32 The Role of DNA DNA = Deoxyribonucleic Acid Found in all cellsContains genetic information that controls cell activities

33 Structure of DNA Composed of nucleotides Each nucleotide has 3 partsSugar called deoxyribose Phosphate group Nitrogen base Adenine (A) Guanine (G) Cytosine (C) Thymine (T)

34 Nucleotides occur on two strands, forming a double helix or twisted ladder.Sides of the ladder are made of the sugar and phosphate groups Rungs of the ladder are made of paired nitrogen bases A always pairs with T G always pairs with C

35 Diagram of DNA

36 DNA as Genetic MaterialThe genetic information is carried in the sequence of nitrogen bases on a DNA strand. The genetic information is carried as “3-letter words” in 3 nitrogen base sequences on the DNA strand.

37 DNA Replication

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39 Protein Synthesis: TranscriptionDNA controls the cell by synthesizing proteins In transcription, DNA directs the synthesis of an RNA molecule. This molecule called messenger RNA takes the information from the DNA in the nucleus out to the ribosomes in the cytoplasm.

40 RNA Structure RNA is Ribonucleic Acid.RNA is a single-stranded molecule. RNA is composed of Nucleotides with 3 parts. Ribose sugar Phosphate group Nitrogen base Adenine (A) Guanine (G) Cytosine (C) Uracil (U)

41 RNA vs. DNA RNA differs from DNA in 3 waysRibose sugar instead of Deoxyribose sugar Single-stranded instead of Double-stranded Uracil instead of Thymine (A pairs with U)

42 Translation: Making ProteinsThe mRNA carries the genetic information in codons, 3 base sequences on the mRNA. Different codons code for different amino acids. Another type of RNA, transfer RNA, matches the codons on mRNA to the correct amino acid.

43 Summary of TranslationmRNA moves along ribosome tRNA brings in proper amino acid Amino acids link to form protein

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45 mRNA Codon Chart

46 METHIONINE – ALANINE- THREONINEReview DNA: T A C C G T T G C mRNA: A U G G C A A C G tRNA: U A C C G U U G C PROTEIN: METHIONINE – ALANINE- THREONINE

47 Mutations Mutations are mistakes or changes in the DNA sequence of nucleotides. Some mutations do not change the sequence of amino acids in a protein. (See codon chart.) Sometimes a single nucleotide change can cause a change in the sequence of amino acids in a protein. (Sickle-cell anemia is caused by a change or substitution in a single nitrogen base.)

48 Some mutations affect more than one codon.Such mutations involve adding or deleting one or more nucleotides. A very different protein may result from such a mutation.

49 Reviewing Mutations Before Mutation mRNA: A U G A A A U U G U C AAmino Acid Sequence: After Mutation mRNA: A U G C A A A U U G U C A Methionine – Lysine – leucine - Serine Methionine – Glutamine – Isoleucine - Valine

50 Genetics Most organisms have two genes for each trait (physical characteristic) Allele = different forms of a gene; letters are used to represent alleles Ex: flower color in peas has 2 alleles, one for purple color (P) and one for white color (p) A dominant allele is expressed even if only one copy is present. A recessive allele is expressed only if two copies are present.

51 Genotype is the genes an organism has; in other words, the allele present.Ex: The genotype of a pea plant for flower color could be PP, Pp or pp. Phenotype is the expression of the genes; in other words, the trait present in an organism because of its genes. Ex: The phenotype of a pea plant for flower color could be purple or white.

52 Predicting Genetics Punnett Square – used to predict the possible genotypes and phenotypes of offspring. EX: Cross Pp with Pp plant

53 P p PP Pp pp Genotype Results: ¼ PP; ½ Pp; ¼ pp or

54 P p PP Pp pp Phenotype Results: ¾ Purple; ¼ White or

55 Two Trait Crosses Punnett Squares may be used to predict the outcome of a two trait cross. In such a cross, the alleles or each gene assort into sex cells independently.

56 Practice crosses of organisms with the following genotypes:1) PpYy x PpYy 2) BbFF x bbFf

57 Classification CategoriesBeginning with the largest or most inclusive grouping, the categories are: Kingdom Phylum Class Order Family Genus species (remember the phrase….?)

58 Grizzly bear Black bear Giant panda Red fox Abert squirrel Coral snake Sea star KINGDOM Animalia PHYLUM Chordata CLASS Mammalia ORDER Carnivora FAMILY Ursidae GENUS Ursus SPECIES Ursus arctos

59 Most Widely Used Classification SchemeSix Kingdom Scheme Archaebacteria Eubacteria Protista Fungi Plantae Animalia

60 Archaebacteria Prokaryotic UnicellularOften live in extreme environments Some are autotrophs Some are heterotrophs

61 Eubacteria Prokaryotic Unicellular Some are autotrophs.Some are heterotrophs. Most do not live in extreme environments.

62 Protista Mostly unicellular eukaryotes A few are multicellularAutotrophs or heterotrophs

63 Fungi Most are multicellular eukaryotes A few are unicellularHeterotrophs Have cell walls

64 Plantae Multicellular eukaryotes Autotrophs Cell wallsSpecialized tissues and organs

65 Animalia Multicellular eukaryotes Heterotrophs Lack cell wallsHave specialized tissues and organs

66 Nervous System: detects changes outside and inside the body and controls the way the body responds to changes Section 35-1 Nervous System Integumentary System Skeletal System Muscular System Circulatory System

67 Figure 35-2 Human Organ Systems Part IIntegumentary System: forms protective barrier around the body; helps prevent water loss and control body temperature; gathers information about surroundings. Section 35-1 Nervous System Integumentary System Skeletal System Muscular System Circulatory System

68 Figure 35-2 Human Organ Systems Part ISkeletal System: helps with movement, protects internal organs, gives body shape and support; stores minerals and produces blood cells. Section 35-1 Nervous System Integumentary System Skeletal System Muscular System Circulatory System

69 Figure 35-2 Human Organ Systems Part IMuscular System: responsible for voluntary movements and involuntary movements. Section 35-1 Nervous System Integumentary System Skeletal System Muscular System Circulatory System

70 Figure 35-2 Human Organ Systems Part ICirculatory System: transports oxygen and nutrients to cells and carries wastes away from cells. Section 35-1 Nervous System Integumentary System Skeletal System Muscular System Circulatory System

71 Body Systems ContinuedDigestive System: breaks down food and absorbs nutrients Respiratory System: moves oxygen into the body and carbon dioxide out of the body. Endocrine System: produces chemical messengers called hormones; helps maintain homeostasis; controls development and growth. Immune System: protects body from infection.

72 Lymphatic System: takes fluid from spaces between cells and returns it to circulatory system; also filters bacteria and other microorganisms from this fluid. Reproductive System: in males, produces sperm; in females produces eggs. Excretory System: removes wastes from the body and helps maintain homeostasis.

73 What is Homeostasis? Homeostasis is the maintenance of a stable internal state. Many reactions and processes are involved in maintaining homeostasis. Ex: Cooperative work of body systems Transport across cell membrane

74 Osmosis as Example of Maintaining HomeostasisOsmosis helps keep the concentration of dissolved substances inside and outside the cell nearly the same. Osmosis is the movement of water across a semipermeable (or selectively permeable) membrane.

75 Review of Osmosis less water more waterWhat will happen in each of the following cells? less water more water What difference will a cell wall make? less water more water

76 Other Examples of HomeostasisRole of Transport Proteins in Regulating Passage Through Cell Membrane Interactions of Various Body Systems Circulatory and Respiratory interact during exercise Nervous, Endocrine, Muscular interact when an organism perceives danger Closing of Stomata when plant leaves begin to dry out

77 Objective 3 The student will demonstrate an understanding of the interdependence of organisms and the environment.

78 Ecosystems Ecosystems include both the living (plants, animals, bacteria, fungi, …) or biotic factors and the nonliving (temperature, soil, weather, …) or abiotic factors Energy flows through ecosystems Matter cycles between living and nonliving things

79 Energy in Ecosystems Energy flows in one direction through ecosystemsOnly about 10% of the energy at one trophic level is transferred to the next level The rest is used up, or lost as heat

80 Consumers get energy from the food they consume. May be classified asProducers such as green plants convert the sun’s energy to chemical energy stored in food. Consumers get energy from the food they consume. May be classified as herbivores (plant eaters), carnivores (animal eaters) omnivores (both plant and animal eaters) Decomposers usually bacteria and fungi, help recycle nutrients.

81 The feeding relationships within an ecosystem may be illustrated with food chains or food websArrows show the flow of energy Food Chain Food Web

82 Pyramids of Biomass The producers always have the largest biomass, followed by herbivores (primary consumers), then carnivores (secondary and tertiary consumers)

83 Pyramids of numbers do not always have to form a pyramidWhy not…?

84 Populations Organisms that make up a population have certain characteristics: belong to same species; live in same area; interbreed with other organisms of the group.

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86 Natural Selection Natural selection occurs when factors in the environment give some organisms advantages over other organisms. Natural selection occurs because organisms have variations or differences. (Remember genetics!)

87 Plant Roots Roots absorb water and minerals. Roots anchor the plant.Roots produce plant hormones and regulate plant growth. 2 types of roots fibrous - better for preventing erosion and absorbing surface water tap - better for reaching underground supplies of water

88 Plant Stems Stems provide support for branches and leaves.Stems provide conduits for transporting material between roots and leaves. Xylem is the tissue to transport water and minerals; mature xylem is dead. Phloem transports the plant’s food including sugars; mature phloem is living.

89 Plants: Leaves Leaves are the primary site of photosynthesis. Leavestrap sunlight; take in carbon dioxide; make food in the form of glucose; release water vapor by transpiration.

90 Diagram of Typical LeafHow might plants in the desert or in the water differ from the above diagram?

91 Examples of Plant AdaptationsVenus-flytrap gets minerals from insects. Water lilies have long roots, floating leaves, and more stomata on top of leaf. (Most plants have more stomata on bottom of leaf to prevent excessive water loss. Spiky leaves protect some plants from herbivores. Dandelions have seeds that can be dispersed by wind.

92 Viruses vs. Bacteria Viruses are smaller than bacteria.Viruses can only reproduce inside a living cell. Diseases caused by viruses include chicken pox, polio, the flu, measles, AIDS, the common cold, and some cancers. Most viruses are harmless to humans and some viruses may be used to cure bacterial infections Viruses cannot be treated with antibiotics