Our Science Final Exam will be given on Thursday. Below, please find Answers to District Final Examination - Review, Grade 7 Honors:
NOTE: CHECK BACK PERIODICALLY WHILE MORE QUESTIONS ARE ANSWERED! ALL QUESTIONS SHOULD BE ANSWERED BY 5 PM TONIGHT.
p. 4 Science Content
- Unit: Studying People Scientifically
- Constant variable - factor that you do not allow to change. Ex: in Dig-In, we used the same amount of soil, same amount of water, same type of equipment, etc.
- Independent Variable - the one factor that the experimenter makes the CHOICE to change, or manipulate. Ex: in Feel the Beat, the thing that we changed was the amount or type of exercise.
- Dependent Variable - the RESULT that you measure at the end. Ex: the amount of water that percolated through in Dig In.
- Qualitative - has information without numbers.
- Quantitative - data that has information with numbers.
- Sample size - number of individuals being tested. Larger sample size helps account for differences between individuals.
- Hypothesis - testable prediction. Must begin with "If", and has "then" in the middle.
List 4-5 components of a good experimental design. Only one Independent Variable Large Sample Size Clearly defined variables Accurate measurement of data An ‘if, then’ statement’ that describes what is being tested Many trials to ensure accuracy and minimize outlier data
- Using “Feel the Beat” and “Dig In”; identify the independent, dependent and constant variables (be able to identify variables when reading other experiments as well).Feel the BeatWhich is the independent variable? * Ask yourself: "What did we change?"* The one thing that you changed or manipulated was the amount of exercise.
Which is the dependent variable?
- Ask yourself: "What were we measuring?" or "What was the result of what we changed?"
- The result you measured at the end was the pulse rate.
- Which factors did we not change? Your pulse-checking routine; test subject (you).
- Which is the independent variable?
type of soil chosen
- Which is the dependent variable?
amount of water that was soaked in (or, in some cases, the amount that percolated through).
- Which are control variables?
Amount of water, amount of soil, equipment.
p. 5 Unit: Body Works
Heart, Lungs, Mouth, Esophagus, Large Intestine, Small Intestine,Pulse Rate, Alveoli
o List the organs of the respiratory system and explain gas exchange.
lungs, larynx, bronchii, alveoli, nose/ mouth, trachea, pharynx
Good image found at:
Gas exchange: Lungs expand, take in air so O2 can be absorbed through walls of capillaries in alveoli. CO2 leaves blood cells at the same time by moving across capillary walls of alveoli and is pushed out when the lungs exhale.
What is the order of the organs in the digestive system through which food passes?
Mouth --> esophagus --> stomach --> small intestine--> large intestine --> rectum --> anus
Explain whether mechanical or chemical breakdown is occurring in each organ of the digestive system.
1) Mouth Both: teeth chew, saliva breaks down
2) esophagus: mechanical, food is squeezed down tube
3) stomach: Both: acids break down food, stomach is muscular to churn food. If you must choose between stomach and mouth, choose mouth as stronger example of an organ that uses both chemical and mechanical digestion.
4) small intestine: mech: nutrients absorbed, muscles squeeze through
5) large intestine/colon: mechanical /absorption6) rectum - storage
7) anus - storage
Describe the structure and function of the respiratory and circulatory systems and their relationship to each other.
Describe how the pulse changes during exercise and explain why this change is taking place.
Unit: Cell Biology and Disease -
- Nucleus, Cytoplasm, Chloroplast, Mitochondria, Cell Membrane, Cell wall, Magnification, Vacuole, Microscope, DNA.
- Given various ocular and objective lens magnifications, calculate the total magnification of using each objective lens. For example, Calculate the total magnification for a 15X ocular and 40X objective:15 x 40 = 600x. Total magnification is 600 times actual size
- Explain the function of the four most common organelles.
Nucleus= control center of the cell
Cytoplasm= the jelly that holds everything together, allows nutrients to travel within the cell
Mitochondria="the powerhouse of the cell", generates most of the cell's energy
Cell Wall - tough, flexible, at times rigid layer that surrounds plant cell membranes for support, protection, structure. (not found in animal cells)
Chloroplast= green material in a plant cell, allows absorbtion of light to make food for plants (not found in animal cells)
Vacuole - storage bubbles found in cells. They are much larger in plant cells, used to hold water and helps plant structure.
DNA - a molecule that carries genetic instructions for development and function of all known living organisms.
p. 7 Compare and contrast bacteria vs. animal cell organelles.
- bacteria - has capsule, cell wall, no nucleus, and a tail (flagellum or cilia)
animal- nucleus; no capsule, no cell wall, no tail
- Compare and contrast single vs. multi-celled organisms and provide examples of each.
- You need a microscope to see single-celled organisms. Ex: Amoebas, Algae, Plankton, and bacteria are single-celled organisms.
- Living things made up of more than one cell are multi-celled organisms.
- Have organs (ex: heart, stomach) and organ systems (ex:stomach, heart, eyes). Many are visible to the naked eye. You are a multiple- celled organism.
Genetics Unitp. 8
- Genes, Genotype, Phenotype, Generation, Probability, chromosome.
- Calculate the probability of future offspring using a Punnett Square. For example, Gg x gg gives the likely following offspring; G g
- g Gg gg g Gg gg
- Be able to distinguish genotypes that result in the dominant phenotype from genotypes which result in the recessive phenotype.
Genotype means the combination of alleles (different versions of the same gene) that is present in the genes of an individual. Phenotype is what is visible on the outside. Dominant genes are shown by an upper case letter, such as 'A'. Dominant genotype includes at least one dominant gene (dominant genotype is shown by either the homozoygous AA or or by the heterozygous Aa). Recessive phenotype appears only when the individual has the recessive genotype for a trait: two recessive genes (ex: aa).
- Describe the important facts about asexual reproduction:
- All DNA comes from one parent, so offspring is identical to the parent. Ex: cloning, budding, fission, runner. Only seen in simpler organisms and some plants.
- Describe the important facts about sexual reproduction:
- Requires DNA or genetic contributions from 2 parents (egg and sperm). Offspring acquire some characteristics from each parent, so they are NEVER identical to a parent. This is typical of animals and many plants.
- What is the importance of genes and where are they located?
- Genes carry the organism's building plans or blueprints coded in their DNA, for each trait. Many genes make up each chromosome. In their body cells, humans carry 23 pairs of (total: 46) chromosomes.
- Describe what is occurring in meiosis and describe the cells which are produced.
- Meiosis is reproduction of sex cells (eggs or sperm). This process takes place in 8 phases which yields 4 daughter cells that have only half the chromosomes of regular body cells (ex: human sex cells only contain 23 Chromosomes, not 46).
- Describe what is occurring in mitosis and describe the cells which are produced.
- Mitosis is reproduction of body cells. Memory trick: Drop a lamp and hurt your toe. To repair this injury to your toe (body cells), your cells do "mi-toe-sis". This process takes place in 4 phases which yields 2 daughter cells that have all the chromosomes of regular body cells (46 for human body cells).
- Weathering, erosion, deposition.
- Describe how weathering, erosion, and deposition create and change landforms.
- weathering breaks down rock; erosion moves rock particles; and deposition is where the rock particles collect. Examples of how these processes create/change landforms include:
- landforms constructed by deposition: deltas, beaches, plains (and some hills).
- erosion has destructive impact to change landforms into: river channels, valleys, cliffs, canyons
- Absorbency (how much water gets soaked up in a certain amount of time),
- Percolation rate -(how much water flows through soil or other materials in a certain amount of time)
- How particle size affects percolation rate:
- larger particle size (e.g., sand) has more spaces between particles, so more water can cling to particles until saturation, THEN water can flow through more quickly.
- Describe absorbency and how it affects the soil.
- Absorbency is how well soil holds water, and this makes water available to plants. too much water in soil will drown plants and make soil particles slide against each other, making the soil unstable for building.
Dig-In/Studying Soils Scientifically
Plate Tectonics -
- Ring of Fire - most earthquakes and 75% of current active volcanoes where Pacific plate subducts under Eurasian and North American plates.
- Differentiate between the three plate boundaries, their movement and what can occur at each boundary.
- Divergent plate boundary - plates move apart, which may cause ocean occupation; Earthquakes; magma upwelling /new crust (ex: sea floor spreading, E. Africa Rift valley).
- Transform plate boundary - move side by side in opposite directions, cause faults and other lithosphere breaks, Earthquakes.
- Convergent plate boundary-plates move together; here you get EQs and:
- mountains and uplift (C vs. C)
- subduction or crust dive and volcanoes (C vs. O); or
- island arcs, deep ocean trenches (O vs. O).
- Describe similarities and differences between CDT and PTT:
- CDT and PTT similarities: Pangaea, continents broke up and moved apart. Evidence includes similar fossils & mountains found on different continents, coal belts & glacial grooves/deposits that line up; change in climate (ex: glacial grooves in Africa and India)
- Differences between CDT and PTT: several supercontinents before Pangaea, driven by convection in the mantle with Sea Floor spreading, plates pulled by convecting magma.