MTTC Integrated Science Exam Questions With Verified Answers

Independent Variable - Answer The experimental factor that is manipulated; the variable whose effect is being studied. Placed on the x-axis (horizontal) on a graph. Dependent Variable - Answer The variable that is measured in an experiment. Placed on the y-axis (vertical) on a graph. Scientific theory - Answer Must be repeatable. Possible to be disproved and capable of change. Sampling and Sample Size - Answer Random sampling is the preferred, but isn't always possible. A large sample will yield the most accurate information. Manipulating Variables - Answer Only one variable should be manipulated at a time. Control variable - Answer A factor that is held constant to test the relative impact of an independent variable Response to Lab Accident - Answer In most cases, 911 should be called immediately. Response to Fire in a Beaker or Flask - Answer Do not use a fire extinguisher. Just place a watch glass or wet towel over it to cut off Oxygen supply. Guidelines for Dissections - Answer Specimens should be rinsed before using. Latex glover preferred. Avoid use of formaldehyde/dispose of correctly. Need to provide alternative for students with moral objections to assingment. Storing Lab Chemicals - Answer Store all in secured, dry area. Acids locked in separate area. Origin of Biological Sciences - Answer Traced back to ancient Greeks (i.e. Aristotle) Andrea Vesalius - Answer Dissected human bodies; created a book on anatomy Anton van Leeuwenhoek - Answer Father of Microscopy, first to see and describe bacteria, yeast plants, and microscopic life found in water Scanning Electron Microscope (SEM) - Answer Instead of a light, a beam of electrons pass through specimen. Resolution about 1,000 times greater than light microscope. Will kill specimen though. Robert Hooke - Answer Famous for Hook's law describing elasticity. But called a "virtuoso", able to contribute findings to any major field in science Carl Von Linnaeus - Answer Famous for binomial system of nomenclature. Each living organism has two names, a genus and species. Considered father of modern ecology and taxonomy Pasteur - Answer Discovered role of microorganisms in the cause of disease, pasteurization, and rabies vaccine. Koch's Postulates - Answer Specific diseases caused by specific pathogens Cell theory - Answer Cell is the common structural unit in plants and animals. Proposed by Mattias Scheleiden and Schwann. Watson and Crick - Answer Discovered the structure of DNA was a double helix (in the 1950s). Made it possible to understand how DNA replicated and synthesized proteins Commonalities Among all Sciences - Answer - Systems, order, and organization - Evidence, models, and explanation - Constancy, change, and measurement - Evolution and equilibrium - Form and function Empirical Evidence - Answer All evidence is empirical; all evidence must be observed by the five sense. Peer-reviewed Journals - Answer Most accepted source for information on scientific experiments and studies Air Pollution - Answer Chemicals in the air; include carbon monoxide, sulfur dioxide, and chlorofluorocarbons (CFC's) Water Pollution - Answer Contaminants enter water by ground runoff or by leaching Thermal pollution - Answer Factories dump water at high temperatures which increases normal water temperatures. This means the water can hold less gas, disrupting the ecosystem Greenhouse gasses - Answer I.e. carbon dioxide and nitrous oxide. Concentration of them is increased by burning fossil fuels. These gasses absorb and trap heat, therefore warming the planet Acid ran - Answer Sulfur and nitrous oxides converted to acids and contaminate water supplies Prokaryotes - Answer Single-celled organisms that do not have a membrane-bound nucleus Flagella - Answer Appendages on bacteria cells; used for movement Pili - Answer Used by bacteria cells to attach to other cells Cell Wall - Answer a thin membrane around the cytoplasm of a cell Cell membrane - Answer a phospholipid layer that covers a cell's surface and acts as a barrier between the inside of a cell and the cell's environment Eukaryotes - Answer organisms whose cells contain a nucleus and other membrane bound organelles Nucleus - Answer a part of the cell containing DNA and RNA and responsible for growth and reproduction Nucleolus - Answer The organelle where ribosomes are made, synthesized and partially assembled, located in the nucleus Ribosomes - Answer site of protein synthesis Endoplasmic Reticulum - Answer an internal membrane system in which components of cell membrane and some proteins are constructed Golgi apparatus - Answer stack of membranes in the cell that modifies, sorts, and packages proteins from the endoplasmic reticulum Lysosomes - Answer An organelle containing digestive enzymes; found mostly in animal cells Mitochondria - Answer Powerhouse of the cell, organelle that is the site of ATP (energy) production Plastids - Answer Include chloroplasts, chromoplasts, and amyloplasts (leucoplasts); only found in photosynthetic organisms Vacuoles - Answer saclike structures that store materials such as water, salts, proteins, and carbohydrates Cytoskeleton - Answer network of protein filaments within some cells that helps the cell maintain its shape and is involved in many forms of cell movement; made up of microtubles, intermediate filaments, and microfilaments Archaea - Answer Single-celled, no nucleus, Live in harsh condisions, oldest organisms on earth Animal vs Plant Cells - Answer Animal cells have centrioles (plant cells dont). Plant cells have cell walls and chloroplasts (animal cells dont) Protists - Answer Single celled eukaryotes; include amoeba, paramecium, and euglena Bacteria - Answer Simplest microorganisms; have a cell wall, but no nucleus, most don't have chlorophyll, so they don't make their own food Characteristics of Living Things - Answer 1. Made of cells, grow, capable of reproduction, and respond to stimuli 2. Adapt to environmental stimuli or perish 3. Carry on metabolic processes. They use and make energy. Mitosis - Answer 1. Division of somatic cells 2. Two cells result from each division 3. Chromosome # is identical to parent cells 4. For cell growth and repair Meiosis - Answer 1. Division of sex cells 2. Four cells result from each division 3. Chromosome # is half the # of parent cells 4. Recombinations provide genetic diversity Gamete - Answer Sex cell Chromatin - Answer Loose chromosomes (present when cell isn't dividing) Chromosome - Answer tightly coiled chromatin (found when the cell is dividing) Homologues - Answer Chromosomes that contain the same information. Contain the same genes Diploid - Answer Pair of chromosomes (somatic cells) Haploid - Answer Half of a pair of chromosomes (sex cells) Steps of Mitosis - Answer IPMAT 1. Interphase - chromatin is loose, chromosomes are replicated; technicallly not a step of mitosis 2. Prophase - chromatin condenses, mitotic spindle forms 3. Metaphase - Chromosomes line-up in the cell center 4. Anaphase - Centromeres split in half; homologous chromosomes separate 5. Telophase - two nuclei form with a full set of DNA; identical to parent cell. Cell is pinched in two (cytokinesis) Steps of Meiosis - Answer Same 5 steps as Mitosis, but is repeated to reduce the chromosome number by one half. One viable egg gets all of the genetic info and the three others are polar bodies (have no DNA) Xylem - Answer transports water Phloem - Answer transports food Cortex - Answer stores food and water Epidermis - Answer protects plant Endodermis - Answer Controls movement in and out of plant Pith - Answer storage in stem Sclerenchyma and collenchyma - Answer support in stem Stomata - Answer Openings in leaf underside. Let CO2 in and H2O out (transpiration) Guard Cells - Answer Control size of stomata Palisade mesophyll - Answer contain chloroplasts in leaves; site of photosynthesis Spongy mesophll - Answer Open spaces in leaf; allows for gas circulation Seed coat - Answer protective covering on seed Cotyldeon - Answer small seed leaf; emerges when seed germinates Endosperm - Answer food supply in the seed Apical meristem - Answer area of cell division Pedicel - Answer supports weight of the flower Receptacle - Answer holds floral organs at flowers base Sepals - Answer Cover the flower prior to blooming Petals - Answer Attract insects to assist in pollination Anther - Answer Male part that produces pollen Filament - Answer Supports the anther Style - Answer Tube that leads to the ovary (female) Stigma - Answer Female part that holds pollen that came from the male part Ovary - Answer contains the ovules Photosynthesis - Answer Plants make carbohydrates from the energy of the sun, carbon dioxide, and water. Oxygen in a waste product. Occurs in the chloroplast Light reactions - Answer reactions of photosynthesis that use energy from light to produce ATP and NADPH Dark reactions - Answer Reactions of photosynthesis that do not require light but use energy produced and stored during light reactions to make glucose Respiration - Answer Glucose, with the help of oxygen, breaks down and produces carbon dioxide and water as waste. Transpiration - Answer Water travels up xylem of the plant. Head and wind increase transpiration, high humidity decreases it Angiosperms - Answer A flowering plant, which forms seeds inside a protective chamber called an ovary. Double fertilization - Answer a fertilization process that requires two sperm to fuse with two other cells Seed dispersal - Answer scattering of seeds; can be done by animals, insects, air, or water Organization of Life - Answer Atoms > molecules > organelles > cells > tissues > organs > organ systems > organism Skeletal system - Answer function is support Muscular system - Answer function is for movement; 3 types: skeletal (attached to bones), smooth (in organs), cardiac (specialized smooth muscle) Nervous System - Answer Basic unit is a neuron - consists of an axon (carries impulses away from cell body), dendrite (carries impulses towards body), and cell body (contains nucleus) Synapses - Answer spaces between neurons Myelin sheath - Answer covers neurons; provides insulation Digestive system - Answer break down food and absorb it into the blood stream; it is then used in cellular respiration Respiratory System - Answer Function is gas exchange of needed oxygen and carbon dioxide waste. Delivers oxygen to bloodstream and picks up carbon dioxide for release out of body (gills for fish, lungs for humans) Circulatory system - Answer function is to carry oxygenated blood and nutrients to all cells and return carbon dioxide waste to be expelled from lungs; leading to and from heart Homeostasis - Answer control of the difference between internal and external environments Osmoregulation - Answer Maintaining correct level of water and salts in body fluids. Thermoregulation - Answer Maintains internal, or core body temperature