Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
7th Grade Science - Chapter 2 Notes Photosynthesis - is a series of chemical reactions that convert light energy, water, and carbon dioxide into the food-energy molecule glucose and give off oxygen. chlorophyll Carbon Dioxide + Water ------------------------ Sugar + Oxygen sunlight Cellular Respiration - is a series of chemical reactions that convert the energy in food molecules into a usable form of energy called ATP. mitochondria Sugar + Oxygen ------------------------------- Carbon Dioxide + Water Xylem - tiny tubes in plants that carry water Phloem - tiny tubes in plants that carry food Stomata - small openings on the undersides of leaves. Where oxygen and carbon dioxide pass through. Chloroplasts - the organelle where photosynthesis occurs Chlorophyll - a plant pigment found in chloroplasts that traps and stores sunlight Glucose - a liquid sugar (food) made by plants; usually made in the leaves Mitochondria - the ‘powerhouses’ of the cell. Where energy is released from food. Water covers 70% of the Earth’s surface. 97% of water is found in the oceans. Water Cycle - a natural process where water moves from the Earth’s surface into the atmosphere and back again by evaporation, condensation, and precipitation. Evaporation - the process during which liquid water changes into a gas called water vapor. Condensation - the process during which water vapor changes into liquid water. Precipitation - any water that falls from clouds to the Earth’s surface. Transpiration - the release of water vapor from leaves and stems of plants. Nitrogen - necessary for life. It is an essential part of proteins and DNA. The most abundant gas in the atmosphere. Nitrogen Fixation - the process that changes atmospheric nitrogen into nitrogen compounds that are usable by living things. This can be done by: lightning, bacteria in the soil, or animal wastes like manure. Bacteria - a group of microscopic unicellular organisms without a membrane-bound nucleus. Oxygen - 2nd most abundant gas in the atmosphere. Needed for cellular processes that release energy. Essential to life! Needed to make water! Carbon - all organisms contain carbon. Animals and humans get it from food. Plants get it from the atmosphere. Greenhouse Effect - the atmosphere contains water vapor and CO2 which help to both reflect and hold in some of the heat energy from the sun. This keeps the Earth from becoming too hot or too cold. Ecosystem - a community of living and non-living things that work together. Organism - any whole and complete living thing. Producers - living organisms that make their own food. Green plants. Consumers - living organisms that do NOT produce their own food, but get their energy by consuming other organisms. Herbivores - consumers that eat plants. Carnivores - consumers that eat other animals. Omnivores - consumers that eat both plants and animals. Detritivores - consumers that eat dead plants and/or animals. Food Chains - a model that shows how energy flows in an ecosystem through feeding relationships. Food Web - a model that shows how food chains in an ecosystem are interconnected. Energy Pyramid - a model to show the amount of energy available in each step of a food chain. Trophic Levels - what the steps in a food pyramid are called. Less energy is available as you go up the steps. Chemosynthesis - the process during which producers use chemical energy rather than light energy to make food.