CET SCIENCE

• Science is defined as a knowledge or system covering general truths or the operation of general laws, especially as obtained and tested through scientific method.
• Scientific Method involves observing natural phenomena and identifying the problem, collecting data, formulating hypotheses, testing hypotheses, analyzing and interpreting data from the experiment, and forming a conclusion.
• A Hypothesis is an assumption or idea that is validated and tested through an experiment.
• A Dependent Variable (DV) is what you measure in the experiment and what is affected by the independent variable.
• Scientific Law is a statement based on repeated experimental observation that describes some aspect of the world.
• Scientific Theory is a tested and widely accepted model that helps explain and predict natural facts and which is based on observations, experiments, and reasoning.
• A comet is a ball of frozen gases, rock and dust about the size of a small town.
• A lunar eclipse is an eclipse in which the full moon passes partially or totally through the umbra of the Earth's shadow.
• Copper Theory was published in 1543 by Copernicus which stated that the earth and the planets rotate around the sun.
• A meteoroid is a small chunk of rock or iron that travels through space.
• All living organisms are either single cells or multicellular organisms composed of many cells working together.
• Most asteroids in the solar system orbit between Mars and Jupiter.
• Biology is derived from the Greek words "bio" meaning life and "logos" meaning study and is defined as the science of life and living organisms.
• A solar eclipse occurs when the Moon passes between the Earth and the Sun, partially or totally obscuring Earth's view of the Sun.
• Cells are the basic unit of life.
• A star is a rocky object in space that can be a few hundred to several thousand miles wide.
• Lithification is the process or processes by which unconsolidated materials are converted into coherent solid rock, as by compaction or cementation.
• Weathering is the breakdown of rocks at the Earth's surface, by the action of rainwater, extreme temperatures, and biological activity.
• Limestone, conglomerate, dolomite, shale are examples of metamorphic rocks which are formed through the alteration of preexisting rocks in response to changing environmental conditions, such as variations in temperature, pressure, and mechanical stress, and the addition or subtraction of chemical components.
• Erosion is a geological process in which earth materials are worn away and transported by natural forces such as wind or water.
• Weather and Climate are related terms, with Weather being the state of the atmosphere with respect to wind, temperature, cloudiness, moisture, pressure, and Climate being the long-term (minimum 30 years) and average weather conditions for a specific region.
• Meteorology is concerned with the processes and phenomena of the atmosphere, especially as a means of forecasting the weather.
• Ecosystem is a system that includes all living organisms (biotic factors) in an area, as well as its physical environment (abiotic factors) functioning together as a unit.
• Translate and copy above the Earth's surface, the mesosphere is a cold layer where the temperature decreases with increasing altitude.
• Ptolemaic Theory states that the Earth is at the center of the universe with the sun, the moon, and the known planets revolving around it in complex orbits.
• Biome is an area of the planet that can be classified according to the plants and animals that live in it.
• Solar System Nebular Theory describes the formation of our solar system from a nebula cloud made from a collection of dust and gas.
• Population is the number of organisms of the same species that live in a particular geographic area at the same time, with the ability to interbreed.
• Ecological factors include all living organisms in the environment, both biotic and abiotic.
• Community is an ecological unit composed of a group of organisms or a population of different species occupying a particular area, usually interacting with each other and their environment.
• Passive transport is the movement of ions and other atomic or molecular substances across cell membranes without the need of energy input.
• Nucleic Acids create DNA and RNA, which store the information needed by cells to create proteins.
• Nucleic Acids are a chain of nucleotides which store genetic information in biological systems.
• The information is stored in multiple sets of three nucleotides, known as codons.
• Diffusion is the net movement of molecules from a region of high concentration to one of lower concentration.
• Mitosis is a process where a single cell divides resulting in two identical cells, each containing the same number of chromosomes as the original cell.
• Prokaryotic cells are simple, single-celled organisms without membrane-bound organelles or nucleus.
• Eukaryotic cells contain a nucleus and organelles, and are enclosed by a plasma membrane.
• Active transport is the movement of molecules across a membrane from a region of lower concentration to a region of higher concentration.
• Polypeptides are large classes of biological molecules consisting of chains of amino acids.