GHSGT Science Review
Characteristics of Science The domain Characteristics of Science will focus on the process skills used in the learning and practice of science, such as testing a hypothesis, record keeping, using correct safety procedures, using appropriate tools and instruments, applying math and technology, analyzing data, interpreting results, and communicating scientific information.
UNITS OF MEASUREMENT
Units of Measurement Scientists use a standard unit of measurement called the International System of Measurement (SI) Commonly referred to as a the metric system
Examples of U.O.Ms Measurement Base Unit Length/Meter (m) Volume /Liter (L) Mass /Kilogram (kg) Force/Newton (N) Temperature/Degrees Celsius ( o C) or Kelvin (K) Time/Seconds (s) Work /Joules Power/Watts
Each unit can be easily changed by powers of 10. These prefixes can be changed to fit the scale needed for that item. Each base unit can be changed by adding prefixes. The prefixes we will be concerned with are: kilo- k-1000 hecta- h-100 deca- D-10 Base-1 deci- d-.1 centi- c-.01 milli- m-.001
Explanation of numbers dealing with prefixes: Kilo means 1000. Therefore, 1 kilometer = 1000 meters. Hecta means 100. Therefore, 1 hectameter = 100 meters. Deci means.1. Therefore, 1 decimeter =.1 meter (or 10 decimeters = 1 meter) Centi means.01. Therefore, 1 centigram =.01 gram (or 100 centigrams = 1 gram) Milli means.001. Therefore, 1 milliliter =.001 liter (or 1000 ml = 1 liter) Notice that the prefixes can be used with meters, grams, liters, and any other metric unit!
Performing in the Lab When performing experiments in the Science lab, there are some key factors that must be involved in the experiment to make the results valid.
Key Terms: Variables: the factors or conditions that are being changed during the experiment Independent Variable: The variable that the experimenter changes (the person changes this one!) Dependent Variable: The variable that changes as a result of the independent variable. (the person does not change this one!)
Control Group: The group in the experiment that is not changed. This is used to compare all other results to it Only different from the experimental group by one variable or condition Experimental Group: The group or groups being experiemented on. All experimental groups are exactly the same except for the one variable that is changed. The same variable has to be changed for each experimental group.
Constants: The constants are all the other factors in the experiment that remain the same during the experiment
Sample Lab You will be presented with a lab situation. Let s work through the following.
The dilemma: A science student wanted to test fertilizers on his houseplants so that he could see which fertilizer would make his houseplants grow the tallest. So he decided to do an experiment with 4 different fertilizers. The student needs to make sure that his experiment is valid, so he must consider all the factors that are involved in his experiment.
First, let us determine the variables involved. Independent Variable: The types of fertilizer used on each houseplant (because this is what the student controlled) Dependent Variable: The plant height (because this was controlled by how good each fertilizer worked)
Now we must consider the different Groups. Control Group: This group would have normal conditions. Therefore, it would not have any fertilizers at all used in it. This one will be used as a comparison. Experimental Groups: There are 4 fertilizers being tested, so there will be 4 experimental groups. Each experimental group will have a different fertilizer used in it.
Now we must consider the constants. These are factors that must be the same in all groups (control and experimental groups!) Same type of plant used Same type of soil used Same size pot being used Same size plant being used at the beginning Same amount of water being used Same amount of sunlight per day Same temperature during the day Same amount of fertilizer being used in every experimental group
Remember that all of the above must be the same. The reason is that we want to make sure that it is the fertilizer that is the only difference. If you were to give all the plants different amounts of water, then we wouldn't know if the different amounts of water or the fertilizer caused different growth rates in the plants.
After doing the experiment, these were the results. Based on these results, we can conclude that Fertilizer C was the best fertilizer (that we tested) for that type of plant. Fertilizer C was also better than the control (normal without fertilizer) group.
Biology There are two Biology domains on the Science GHSGT.
Animal Cell
Plant Cell GHSGT Science Review 2006
Homeostasis The maintenance of a stable internal environment, by regulating substances traveling into and out of the cell.
Passive Transport Osmosis = the unregulated movement of water across the cell membrane Does not require energy to take place Cellular response in 3 types of solutions: Isotonic = same conc. materials as the cytoplasm Hypertonic = greater conc. of materials than the cytoplasm Hypotonic = lesser conc. of materials than the cytoplasm
Examples Animal cell
Example Plant Cell
Organic Compounds Carbohydrates = used for short-term storage of energy and fuel (converted to ATP) Fats = used for long-term storage of energy and fuel (also eventually converted to ATP) Proteins = used for growth and repair of cells and tissues. Many proteins function as enzymes, allowing physiological reactions to occur (no reaction = NO LIFE!) Nucleic acids (DNA, RNA) = store information for reproduction of cells
DNA DNA = deoxyribonucleic acid shape = twisted ladder (double helix) Backbone (sides of ladder) = alternating sugars and phosphates Rungs of ladder = nitrogen bases (C, G, A, and T)
DNA vs. RNA DNA = A, T, G, C, double helix A bonds to T, G bonds to C RNA = A, U, G, C, single strand RNA bonds to DNA to read the genetic code A bonds to U, G bonds to C
DNA Replication Replication = DNA copies itself during mitosis, meiosis
DNA Replication con t.
Genetics Gene = sequence of 3 base pairs in DNA, controls traits in all living things Can be one of two types (alleles): Dominant = always expressed in phenotype Recessive = only expressed when there is no dominant gene present Homozygous = 2 of the same allele (RR, rr) Heterozygous = 1 of each type of allele (Rr)
Genetic Crosses Punnett Square = allows prediction of traits in offspring from parent s known traits Monohybrid cross = shows offspring that would results from 2 heterozygous parents for 1 trait Dihybrid cross = 2 parents heterozygous for 2 traits R r R RR Rr r Rr rr 3 red (RR, Rr) : 1 white (rr) RT Rt rt rt RT RRTT RRTt RrTT RrTt Rt RRTt RRtt RrTt Rrtt rt RrTT RrTt rrtt rrtt rt RrTt Rrtt rrtt rrtt 9 red/tall : 3 red/short : 3 white/tall : 1 white/short
Cellular Reproduction Mitosis -somatic (body) cell reproduction -conserves original chromosome number (diploid) -produces daughter cell identical to parent -Interphase is a period between cell divisions for resting & growth.
Cellular Reproduction Meiosis occurs in reproductive organs produces gametes (sex cells) containing ½ the chromosome number (haploid) of the parent cell requires two cell divisions in order to reduce original chromosome number by ½ (haploid)
Crossing Over crossing over = varies the genetic information of the offspring
Classification Taxonomy = study of how organisms are named and classified. System is from most general to most specific: Kingdom Phylum Class Order Family Genus Species King Phillip Comes Over For Great Spaghetti. Binomial Nomenclature = scientific name for organism; consists of Latin genus & species designations ex: humans = Homo sapiens
Five Kingdoms Mushrooms, Yeast Athlete s foot Bread Mold Euglena, paramecium Bacteria, virus blue-green algae
Biomes (Ecology) Aquatic = marine (saltwater) and freshwater Majority of world s oxygen produced by phytoplankton here Terrestrial (from coldest to warmest) Tundra = temp never above zero Taiga = coniferous forest (think Canada) Grassland = prairies and savannah Desert = arid (very dry) Temperate = deciduous forest (trees lose leaves) Think Georgia! Tropical = Rain forest, lots of rain, 80 degrees
Biomes
Resources Non-Renewable = any resource that is used faster than it can be replaced Fossil fuels (coal, oil, natural gas) Metal ores (copper, aluminum, iron) Building materials (rock, such as granite, limestone, sandstone, marble) Renewable = any resource that can be continually replaced or used Solar/wind/geothermal/nuclear energy Plants and animals (biomass)
Communities Niche = role an organism plays in its environment Habitat = where the organism lives Feeding Relationships Producers: Autotrophs = makes its own food (plants) Heterotrophs = must obtain food elsewhere (animals) Consumers: Herbivore = eats autotrophs Carnivore = eats herbivores Decomposer = breaks down organisms Omnivore = eats everything above Predation = one organism kills another in order to consume them for energy (animal-animal relationship)
Communities, con t. Living relationships Commensalism = one organism benefits, the other is unaffected Mutualism = both organisms benefit Parasitism = one organism benefits, the other is harmed Kudzu is a parasite In 2000, the City of Tallahassee implemented a program that uses sheep to mob-graze kudzu, an efficient and effective method of eliminating the invasive vine. The program is saving hundreds of acres of native plants and trees from destruction without using pesticides or heavy labor.
Energy Flow (Ecosystem)
Physical Science There are 3 Physical Science domains on the Science GHSGT.