ATTACKING THE SCIENCE TAKS

1. ATTACKING THE SCIENCE TAKS CYPRESS LAKES

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

3. Importance of a Hypothesis • Science 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 • A 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. CHARTS 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!

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

10. GRAPHSFrom Pure Data  Visual There are 3 different types of graphs that display data in different ways: • Bar graph • Line graph • Pie/Circle graph

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

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

15. SAMPLE TAKS QUESTIONS 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

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.

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.

19. SAMPLE TAKS QUESTIONS 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 understanding of the organization of living systems.

21. Organization of Living Systems Atoms 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 Protists • Have 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: Nucleus Nucleolus Chloroplasts Vacuole Mitochondria Cytoplasm Cell Membrane Cell Wall

27. Animal Cell

28. Functions of Organelles

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 glucose • Occurs in plant cells in chloroplasts Carbon dioxide + WaterGlucose + 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 + OxygenCarbon dioxide + Water + Energy C6H12O6 + 6O2 6CO2 + 6H2O + ATP

32. The Role of DNA • DNA = Deoxyribonucleic Acid • Found in all cells • Contains genetic information that controls cell activities

33. Structure of DNA • Composed of nucleotides • Each nucleotide has 3 parts • Sugar 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 Material • The 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

39. Protein Synthesis: Transcription • DNA 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 ways • Ribose sugar instead of Deoxyribose sugar • Single-stranded instead of Double-stranded • Uracil instead of Thymine (A pairs with U)

42. Translation: Making Proteins • The 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 Translation • mRNA moves along ribosome • tRNA brings in proper amino acid • Amino acids link to form protein

45. mRNA Codon Chart

46. Review 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 A Amino Acid Sequence: After Mutation mRNA: A U G C A A A U U G U C A Amino Acid Sequence: 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.