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Biology EOC study guide

What is the study of Biology?
The science that seeks to understand the living world. Studies molecules, cells, organisms, populations of a single organism, communities of populations living in the same area, and the biosphere.
Contrast unicellular and multicellular organisms.
Unicellular only consists of a single cell, and multicellular organisms consist of many cells.
What is homeostasis? Give an example.
Homeostasis is the process by which organisms maintain a relatively stable internal environment. Example: regulating body temperature.
What are the main characteristics of life?
The main characteristics of life include: living things are made up of cells, living things reproduce, living things are based on a universal genetic code, living things grow and develop, living things use energy (metabolism), living things respond to their environment, living things maintain a stable internal environment, and living things change over time (groups change).
What are the steps of a scientific method?
State the problem, research, form a hypothesis, experiment using variables, collect data, derive a conclusion.
How do scientists use the scientific method?
Scientists follow the scientific method in all experiments performed to ensure proper results and data.
What are the purposes of using microscopes in science?
Microscopes aid in magnifying images of structures that are too small to see with the unaided eye.
What is an element?
An element is a substance consisting entirely of one type of atom.
What is an atom?
An atom is the basic unit of matter.
What is a molecule?
A molecule is the smallest unit of compounds.
What is a compound?
A compound is a substance formed by the chemical combination of two or more elements in definite proportions.
Describe the atomic structure of an atom.
An atom consists of protons, neutrons, and electrons. The protons(+) and neutrons (neutral) are formed in the nucleus. The electrons (-) orbit, or move around, the nucleus. The atomic number on the periodic table is determined by the number of PROTONS present.
Describe the different types of atomic bonding (covalent, ionic, hydrogen)
Covalent bonds form when electrons are shared between atoms. Ionic bonds form when two or more electrons are transferred (lost or gained) from one atom to another. Hydrogen bonds (opposite charges) are the strongest bonds that can form between MOLECULES. Hydrogen bonds are the bonds present in a DNA molecule.
What are solutions?
Solutions are a mixture of two or more substances in which the molecules of the substances are evenly distributed. Ex: Salt Water
What is the difference between a solvent and a solute?
A solvent is a substance in which a solute is dissolved to form a solution. A solute is a substance that is dissolved in a solvent to make a solution.
What does "polarity" mean in regards to the properties of water?
Polarity involves a substance that has a distinct positive end and a distinct negative end. Water is an example! Because it is polar, water molecules attract to other water molecules.
What are organic compounds?
An organic compounds is any compounds that contains carbon. Organic chemistry is the study of these compounds.
What is the main function of ATP? How is ATP made?
ATP provides and stores energy for many cellular processes. ATP is made when a single phosphorus is added to ADP.
What are three carbohydrates?
Glucose, fructose(monosaccharides), galactose, disaccharides, and glycogen (polysaccharides). Elements: carbon, hydrogen, and oxygen in a 1:2:1 ratio. Monomers are monosarccharides.
What are the role of proteins and enzymes?
Proteins are polymers of amino acid that control the rate of reactions and regulate cell process. Enzymes are catalysts (remain unchanged during the reaction) that speed up chemical reactions that take place in cells and break down certain substances. They speed up a reaction by lowering the activation energy.
What is a positive test for starch? Sugar? What indicator gives that response?
A positive test for starch is a change in the appearance of iodine. Iodine turns black. Sugar is the change in the appearance of Benedict's solution- goes from blue to orange.
What is a positive test for lipids? What indicator gives that response?
A positive test for lipids is clear spots on brown paper. (Think grease spots on your Fast Food bags!) Sudan IV- dark red to orange!
What is a positive test for proteins? What indicator gives that response?
A positive test for proteins is a change in the Biuret reagent. It turns a blue color to a purple color when positive for proteins. Proteins include carbon, hydrogen, oxygen, and nitrogen. Monomers are amino acid.
What are lipids? Give an example of a lipid.
Lipids are made mostly from hydrogen and carbon atoms (consist of glycerol and fatty acids) and can be used to store energy. Examples: Oils. Made of carbon, hydrogen, oxygen, nitrogen and phosphorus. Monomers are nucleotides.
Describe a prokaryotic cell in comparison to a eukaryotic cell.
Prokaryotic cells do not contain a nuclei or other organelles, except cell membranes, cytoplasm, and DNA. (example:bacteria). Eukaryotic cells are much more complex, and they do contain a nucleus and organelles. (example:animals).
What is the cell theory?
The cell theory states: all living things are composed of cells, cells are basic units of structure and function in living things, and new cells are produced from existing cells.
Why is the surface area-to-volume ratio important in cells?
Changes in the surface area to volume ratio have important implications for limits or constraints on organism size (too large result in lack of nutrients, size and information overload, and excess of wastes) Cells splits into two cells to avoid this (mitosis)
List and describe the main organelles present in an eukaryotic cell.
Cell Membrane: Doorway-allows substances in and out.
Cytoplasm: Jelly-like substance inside a cell.
Nucleus: Control center-brain.
Nuclear Membrane: protects the nucleus.
Mitochondria: powerhouse-source of energy.
Endoplasmic Reticulum: transportation system.
Ribosomes: protein factories
Golgi bodies: post office- enzymes attach carbs
Vacuole: storage tanks
Lysosomes: clean up crew- break down substances.
Cell Wall (plant): Fence-structure and support
Chloroplast (plant): Energy Producers-photosynthesis.
What is the role of the plasma membrane? What does it mean to be selectively permeable?
The plasma membrane regulates what leaves and enters the cell and also provides protection and support. If selectively permeable, the membrane only allows certain material to enter and leave the cell.
What are phospholipids?
Make up the lipid bilayer. Phospholipids are fat derivatives in which one fatty acid has been replaced by a phosphate group and one of several nitrogen-containing molecules. They are amphiphlic molecule, meaning a portion can be dissolved in water and a portion that cannot dissolve in water.
Describe the fluid mosaic model.
The fluid mosaic model states that the phospholipid bilayer behaves like a fluid more than it behaves like a solid. The membrane's lipids and proteins can move laterally within the bilayer, like a boat on the ocean.
What does the cell membrane have embedded proteins?
The proteins help substances that can not easily pass through the membrane by allowing them to pass through protein channels (faciliated diffusion)
Describe multicellular organization (steps from cells to organisms)
Cells to tissue to organs to organ systems.
What is passive transport? Give three examples.
Passive transport involves the movement of substances across a cell membrane that does not require the input energy. Examples: diffusion, osmosis( movement from higher concentration to lower concentration, and faciliated diffusion.
When the concentration of solute molecules outside the cell is higher than the concentration in the cytosol.
when the concentration of solute molecules outside the cell is lower than concentration in the cytosol.
when the concentration of solutes outside and inside the cell are equal.
What is a concentration gradient?
The movement of a substance from an area with a high concentration to an area of low concentration. In active transport, the substances move against the concentration gradient (move from low to high)
What does it mean to have equilibrium in a cell?
Equilibrium is a stable situation in which forces cancel one another (no net movement in or out of cell) Think Isotonic!
Describe active transport. Give an example.
In active transport the substances move across the concentration gradient (move from low to high) . Example: sodium/potassium pump.
Contrast autotrophs and heterotrophs.
Autotrophs have the ability to capture energy from sunlight or chemicals and use it to produce its own food (also known as producers). Heterotrophs obtain their energy from the food it consumes (also known as consumers.)
What are the reactants and products in photosynthesis?
The reactants of photosynthesis are carbon dioxide, water, and light. The product is sugar (glucose) and oxygen.
What are the roles of chloroplast in a plant cell?
Chloroplasts use the energy from sunlight to make energy-rich food molecules in a process known as photosynthesis.
Distinguish between photosystems 1 and 11 in photosynthesis.
Photosynthesis starts in photosystem 2 (light is absorbed and transfered to electrons. After photosystem 2, the process continues to photosystem 1 (electrons are picked up by NADP+ into the energy carriers ATP and NADPH.
What happens during the light reaction of photosynthesis?
The light dependent reactions produce oxygen gas and convert ADP and NADP+ into the energy carrieres ATP and NADPH.
Describe the electron transport chain.
High energy electrons move from photosystem 11 through the electron transport chain to photosystem 1.
What is the Calvin Cycle (dark cycle)?
The Calvin Cycle uses ATP and NADPH from the light-dependent reactions to produce high-energy sugars. Need the addition of carbon dioxide!
Discuss the rate of photosynthesis.
Many factors affect the rate of photosynthesis includes: water shortages, temperature, and intensity.
What are the reactants and products of cellular respiration?
Reactants of cellular respiration include oxygen and glucose. The products are carbon dioxide, water and energy.
Describe the process of glycolysis.
Glycolysis is the process in which one molecule glucose is broken in half, producing two molecules of pyruvic acid, a 3-carbon compound.
What is the difference between aerobic and anaerobic respiration?
Aerobic respiration requires oxygen, and anaerobic respiration does not require oxygen.
What is the outcome of the Krebs Cycle?
During the Krebs Cycle, pyruvic acid (Acetyl-CoA) is broken down into carbon dioxide in a series of energy-extraction reactions.
When does the process of fermentation take place? What are the two main types of fermentation?
Fermentation takes place when oxygen is not present during glycolysis. The two main types of fermentation are alcoholic fermentation (yeast cells) and lactic acid fermentation (muscle cells)
Describe the structure of a DNA molecule. What are the components present?
DNA molecules are a double-helix structure (winding staircase). DNA molecules consist of a chain of nucleotides, a sugar-phosphate backbone (covalent bonds) and hydrogen bonds holding the base pairs together.
The structure of a condensed chromosome.
Chromosomes consists of 2 identical chromatids and a centromere.
What is a chromatin?
Chromatin is DNA that is not condensed (in the nucleus).
What is the role of histones?
Histones are globular protein molecules around which DNA is tightly coiled in chromatin.
Discuss the difference between sex chromosomes and autosomal chromosomes.
Sex chromosomes determine the sex of a child (male or female). Autosomal chromosomes determine other traits (heredity).
What are homologous chromosomes?
Chromosomes that each have a corresponding chromosome from the opposite-sex parent.
How is a karyotype useful in genetics?
Karyotype are a set of photographs of chromosomes grouped in order in pairs. Are used to examine an individual's chromosomes.
Contrast a haploid cell verses a diploid cell.
Haploid cells contain only a single set of chromosomes and therefore only a single set of genes. Diploid cells contain both sets of homologous chromosomes.
What is binary fission?
Binary fission is a type of asexual reproduction in which a prokaryote replicates its DNA, and divide in half, producing two identical daughter cells. Budding is asexual reproduction.
Discuss the cell cycle (include G1, S, and G2.
Series of events that cells go through as they grow and divide. G1=cell growth, S=DNA replication, G2=preparation for mitosis. All part of interphase.
What are the phases of mitosis?
(interphase and cytokinesis-not a phase of mitosis!) Interphase in not a phase of mitosis!) Prophase, Metaphase, Anaphase, and Telpphase.
What are gametes?
Specialized cells involved in sexual reproduction. Egg cells-oogensis. Sperm cells- spermatogensis.
What is crossing over? Where does it occur during the process of meiosis?
Crossing over is the process in which homologous chromosomes exchange portions of their chromatids during prophase 1 of meiosis,
What is the difference between sexual and asexual reproduction?
Sexual reproduction is the process by which two cells from different parents unite to produce the first cell of a new organism. Asexual reproduction is the process by which a single parent reproduces by itself.
Describe the study of genetics.
Genetics is the scientific study of heredity.
Define: Heredity, dominant allele, recessive allele.
Heredity is the genetic transmission of characteristics from parent to offspring. Dominant alleles mask the recessive alleles. Recessive will only show up-if dominant allele is not present~
What was Mendel's experiment? How did it determine traits passed from generation to the next?
Mendel studied traits and gene transfer by cross-pollinating pea plants. He used Punnett Squares to determine the probability of traits being passed from one generation to another.
Discuss pollination (self vs. cross)
Self-pollination includes only one plant that produces offspring identical to them. Cross-pollination is the fertilization of male sex cells in pollen from the flower on one plant with the egg cell of a flower on another plant (hybrid)
What are the P, F1, and F2 generations?
P=parent generation. F1=first generation, F2=second generation.
Contrast homozygous and heterozygous.
Homozygous is the term used to refer to an organism that has two identical alleles for a particular trait (TT or tt). Heterozygous is used to refer to an organism that has two different alleles for the same trait (Tt).
What is a genotype?
Genotype is the genetic makeup of an organisms.
What is a phenotype?
Phenotype is the physical characteristics of an organism.
Discuss the Law of Segregation (alleles)
States that a pair of factors is segregated, or separated, during the formation of gametes.
What is the Law of Independent Assortment?
states that each chromosome (or pair) separates independently of each other to form the gametes (egg and sperm)
How does probability help us understand the passing of traits from one generation to the next?
It is simply the likelihood that a certain trait will be passed on to the next generation.
What are alleles? What is their function?
Each of several alternative forms of a gene. Ex. AA or Aa, the individual A is an allele. AA is alleles for a gene.
What do Punett Squares determine?
They aid in predicting the probability that certain traits will be inherited by offspring.
What is a monohybrid cross? Dihybrid crosses?
A monohybrid cross involves the crossing of just one
trait. Ex. AA x Aa. A Dihybrid cross involves crossing 2 traits. Ex. AABb x AaBB
What is the result of incomplete dominance?
? A blending of the traits. Red flowers x White flowers =
pink flower in heterozygous offspring