Tutor profile: Hayley B.
Subject: Environmental Science
What are the levels of ecological organization and what does each one represent?
1. Species. This is the smallest level. Species are usually genetically related individuals who can mate with one another to produce viable offspring. 2. Population. This is a group of the same species who live together in a area and interact with each other. 3.Community. This is an accumulation of the different species and their populations in an area where they all interact together. 4. Ecosystem. This includes all living organisms and their populations. They interact using biotic and abiotic factors in their environment. 5. Biosphere. This is everything above wrapped up together on Earth. It encompasses all global processes.
Subject: Basic Chemistry
What is the difference in a physical change and a chemical change?
A physical change only affects the form of the chemical substance. Chemical composition is not affected during this process. For example, water consists of 2 Hydrogens and 1 Oxygen (aka H2O). At room temperature, H2O is free flowing (It is a liquid). If it is subjected to temperatures at its freezing point, it will condense into a solid state which is what we know as ice. Chemical changes are when the chemical composition of a species is altered. For example, if we take Acetic Acid (Vinegar or CH3COOH) and mix it with Sodium Bicarbonate (Baking soda or (NaHCO3), a chemical change will take place creating Carbon Dioxide (CO2) gas.
Could you explain active transport within the cell?
Active transport is the movement of some molecule against a concentration gradient. This is defined as an transport of a molecule from an area of low concentration to high concentration. Unlike passive transport, this takes energy to perform. As a result of needing to use energy, in every cells lipid bilayer, there are thousands of specialized proteins that help aid in the active transport process.
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