DNA 1 Backbone: Sugar (Deoxyribose) Phosphate DNA 2 Function: Contains hereditary information Contains code for making proteins Protein Synthesis: DNA  mRNA  Amino Acid The order of bases in DNA determines the order of amino acids in the protein. Mutations: Errors in the code Mess up the amino acid sequence… …keeps the protein from doing its job correctly Causes of Mutations: Heat Chemicals UV Radiation Nuclear Radiation Cell DivisionReproduction Mitosis: Asexual reproduction in single celled organisms Used to make new body cells in multicellular organisms Results in 2 identical, diploid cells Meiosis: Used to make sex cells (gametes) to be used in sexual reproduction Results in 4 unique, haploid daughter cells DIPLOID Cells that have 2 copies of each chromosome 2n Somatic (body) cells HAPLOID Cells that have 1 copy of each chromosome n Sex cells (gametes) DNA Replicates Before Cell Division ASEXUAL Single-celled organisms Cell just divides Mitosis Budding Binary fission 2 daughter cells are identical to parent cell No genetic variation SEXUAL Multicellular organisms Haploid gametes combine in fertilization Diploid zygote has genes from both parents Genetic variation from one generation to the next Rungs: Adenine ---Thymine Cytosine --- Guanine Made of: Nucleotides

Cell StructureCell Organelles Organelles in Plant and Animal Cells: Nucleus – holds the cell’s DNA Cell Membrane – Holds the insides in; controls what goes in and out of the cell Mitochondria – provides energy for the cell in the form of ATP Vesicle – transports materials around inside of the cell. Ribosome – assembles proteins Golgi apparatus – sorts and packages proteins to be sent out of the cell Rough ER – proteins are folded and formed as they are created. Smooth ER – lipids are formed Cytoplasm – gel-like “filling” of the cell Organelles in Animal Cells only: Centrioles – Generate the spindle for cell division Lysosomes – contain enzymes for breaking down waste in the cell (rare in plants) Organelles in Plant Cells only: Chloroplast – location of photosynthesis Cell Wall – provides support, structure, and protection for the cell Central Vacuole – holds water; provides support to the cell’s shape Cell Membrane TransportCell Membrane Structure Active Transport: Requires energy Moves against the concentration gradient Na + /K + Pump Endocytosis/exocytosis Passive Transport: Does not require energy Moves with the concentration gradient Diffusion (facilitated and simple) Osmosis What is it made of? Phospholipid bi-layer Proteins Cholesterol Carbohydrates Membrane Proteins Channel – allow movement in and out Pump - force ions in or out Cholesterol Keeps the membrane fluid Osmosis

Photosynthesis and Cellular RespirationNatural Selection Natural Selection Requires: There is variation of alleles There is reproduction Alleles are determined favorable or not Alleles are passed on to offspring Peppered moths are either dark or light in color. Some blend with the dark trees and others blend in with the light trees. If they blend, they will live longer, and reproduce. Traits and InheritanceEcology 1 Key Terms: Trait – an observable characteristic that can be inherited. Allele – a version or variation of a trait. Photosynthesis: Carried out by plants. Occurs in the chloroplast. sunlight CO 2 + H 2 O  C 6 H 12 O 6 + O 2 Cellular Respiration: Carried out by plants and animals. Occurs in the mitochondria. C 6 H 12 O 6 + O 2  CO 2 + H 2 O C 6 H 12 O 6 Cellular Respiration Photosynthesis Energy Flow in Ecosystems As energy passes up through the trophic levels, only 10% of the energy in a level is available to go to the next level. Organisms at the higher levels have to eat more food to get enough energy.

Experimental DesignEcology 4 Invasive Species: Species that are not normally in an ecosystem are added to the ecosystem, naturally or by man. Ecology 3Ecology 2 Carrying Capacity The carrying capacity of a biological species in an environment is the population size of a particular species that the environment can support, given the food, habitat, water and other necessities available in the environment. Independent Variable (IV) The variable that the experimenter changes…on purpose Dependent Variable (DV) The variable that the experimenter measures…as a result of the IV. Food Webs If the squid population decreases suddenly, the crab eater seal will have to hunt more for krill and other small fish to avoid dying. Also the Emperor penguin population is likely to decrease in numbers due to lack of food. What will happen to this ecosystem if the fish population vanished, instead? Zebra mussels are an invasive species. Unionid mussels are native to the ecosystem. What happened to the population of the native species after the arrival of the invasive species? What happened to the population of the invasive species? Constants Variables that are kept the same throughout the experiment. Groups Control Group - The group in an experiment that all other groups are compared to. No changes are made. Everything is constant. Experimental Group – The group in An experiment in which one variable is different from the control group. There are usually several experimental groups in a good experiment.