Biology Final Review

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Biology Final Review
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Chromosomes

• Chromosomes are DNA its associated proteins.
• We have 46 chromosomes or 23 pairs of
  chromosomes.
• In a prokaryotic cell, it is the main ring of
  DNA.

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Autosomes vs. Sex Chromosomes

• Autosomes are any chromosomes that are not
  directly involved in determining the sex of an
  individual.
• We have 22 pairs.
• Sex chromosomes contain genes that will determine
  the sex of the individual.
• We have one pair.
• Females are XX.
• Males are XY.

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Autosomes vs. Sex Chromosomes
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Gametes

• Gametes are an organisms reproductive cells.
• Females gametes are eggs or ova.
• Males gametes are sperm.

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Haploid vs. Diploid

• Haploid refers to a cell (gamete) that contains
  only 1 set of chromosomes.
• It is represented by n.
• Diploid refers to a somatic or body cell that
  contains 2 sets of chromosomes.
• It is represented by 2n.

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Define Haploid

• Describes a cell, nucleus or organism that has
  only one set of unpaired chromosomes.

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Define Diploid

• A cell that contains 2 sets of haploid
  chromosomes
• Body or somatic cells contain a diploid number of
  chromosomes.

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Karyotype

• A picture of the chromosomes found in an
  individuals cells at metaphase of mitosis
  arranged in homologous pairs in order of
  diminishing size with the sex chromosomes last.
• Downs Syndrome
• is trisomy 21.

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Parts of a Microscope
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Microscopes and Magnification

• Ocular lens x objective lens total
  magnification
• Magnification making image appear larger
• Resolution clarity of image

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Cell Theory

• All living things are made of cells.
• Cells are the basic units of structure and
  function in organisms.
• All cells come from existing cells.

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Prokaryote vs. Eukaryote

• Prokaryote
• No nucleus
• No membrane bound organelles
• Circular DNA
• Relatively small
• Reproduce quickly (20 min.)
• Examples Bacteria

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Prokaryote vs. Eukaryote

• Eukaryote
• Nucleus
• Many membrane bound organelles
• Linear DNA
• Relatively large
• Reproduce slowly (24 hours)
• Examples Plants, animals, fungi protists

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Cell Parts Functions

• Cell membrane
• Controls what enters leaves a cell separates
  protects the cell from the environment.
  
• Nucleus
• Contains the DNA in eukaryotic cells controls
  cellular activities.
• Vacuole
• Membrane bound sac that stores water, may also
  contain ions, nutrients waste.

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Cell Parts Functions

• Chloroplast
• Organelle that uses light energy to make
  carbohydrates from CO2 H2O.
• Cytoplasm
• Region of the cell within the membrane that
  includes the fluid, the cytoskeleton and all of
  the organelles except the nucleus.
• DNA
• Material that contains the information that
  determines hereditary characteristics.

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Cell Parts Functions

• Ribosomes
• Organelle composed of RNA protein site of
  protein synthesis.
• Mitochondrion
• Cell organelle surrounded by 2 membranes is the
  site of cellular respiration, which produces ATP.
  
• Cell Wall
• Rigid structure that surrounds the cell membrane
  provides support to the cell.

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5 Stages of the Cell Cycle
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5 Stages of the Cell Cycle

• The first 3 stages are collectively called
  interphase. (90 of a cells life is spent here.)
• First growth (G1) phase
• Cell grows rapidly carries out routine
  functions. (Major portion of a cells life is
  spent here.)

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5 Stages of the Cell Cycle

• Synthesis (S) phase
• Cells DNA is copied.
• Each chromosome consists of 2 chromatids attached
  at the centromere.
• Second growth (G2) phase
• Preparations are made for the nucleus to divide.
• Microtubules are rearranged.
• Organelles are manufactured or reproduced.

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5 Stages of the Cell Cycle

• Mitosis
• The nucleus of a cell divides into 2 nuclei each
  with the same and kinds of chromosomes as the
  original cell.
• Cytokinesis
• The cytoplasm divides and 2 new cells are formed.

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3 Checkpoints

• A checkpoint is an inspection point at which
  feedback signals from the cell can trigger the
  next phase of the cell cycle or delay it.
• Cell Growth (G1) checkpoint at the end of the G1
  phase
• Makes the decision of whether or not a cell will
  divide.

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3 Checkpoints

• DNA synthesis (G2) checkpoint at the end of the
  G2 phase
• DNA replication is checked by DNA repair enzymes.
• Mitosis checkpoint at the end of mitosis
• Triggers the exit from mitosis

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4 Phases of Mitosis

• Prophase
• Chromosomes become visible.
• Nuclear envelope dissolves.
• The spindle forms.
• In animal cells, the centrioles move to opposite
  poles and the spindle forms between them.

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4 Phases of Mitosis

• Metaphase
• Chromosomes move to the center of the cell line
  up along the equator.
• Spindle fibers link the chromatids of each
  chromosome to opposite poles.

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4 Phases of Mitosis

• Anaphase
• Centromeres divide.
• The 2 chromatids (now called chromosomes) move
  toward opposite poles as the spindle fibers
  attached to them shorten.

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4 Phases of Mitosis

• Telophase
• A nuclear envelope forms around the chromosomes
  at each pole.
• The chromosomes uncoil and return to chromatin
  form.
• The spindle dissolves.
• Cytokinesis begins.

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Cytokinesis

• Division of the cytoplasm of a cell
• Follows the division of the cells nucleus by
  mitosis or meiosis
• Cytokinesis in animal cells occurs when a belt of
  protein threads pinches the cell membrane in
  half.
• Cytokinesis in plant cells occurs when vesicles
  from the Golgi apparatus fuse to form a cell
  plate.

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Cytokinesis

• Cytokinesis in Cytokinesis in
• animal cells plant
  cells

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Define Meiosis

• A process in cell division during which the
  number of chromosomes decreases to half the
  original number by two divisions of the nucleus,
  which results in the production of sex cells
  (gametes or spores)

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What are the 4 things that give rise to variation
within a species?

• Independent assortment
• Crossing-over
• Random fertilization
• Mutations

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Differentiate between spermatogenesis oogenesis.

• Spermatogenesis
• 2 nuclear divisions in which the cytoplasm is
  divided equally
• 4 sperm produced from parent cell

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Differentiate between spermatogenesis oogenesis.

• Oogenesis
• First nuclear division, cytoplasm divides
  unequally one of the cells gets nearly all of
  the cytoplasm
• This cell will ultimately give rise to one egg
  the 3 polar bodies will die

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Complete the following diagrams
2n
2n
2n
Process Mitosis
Process Meiosis
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Compare Mitosis and Meiosis
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What are the 3 different ways asexual
reproduction occurs?

• In asexual reproduction, a single parent passes
  exact copies of all of its DNA to its offspring.
• Fission
• Fragmentation
• Budding

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Nondisjunction

• One or more chromosomes fail to separate properly
  during meiosis.
• One gamete ends up receiving both chromosomes and
  the other gamete receives none.
• Trisomy occurs when the gamete w/ both
  chromosomes fuses w/ a normal gamete, resulting
  in an offspring w/ 3 copies of a chromosome
  instead of 2.

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Diffusion vs. Osmosis

• Diffusion
• The movement of particles from regions of higher
  concentration to regions of lower concentration.
• Ex perfume spreading across a room.
• Osmosis
• The diffusion of water from an area of high
  concentration to an area of low concentration
  across a membrane.
• Ex Getting thirstier when you drink salt water.

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Passive vs. Active Transport

• Passive Transport
• Does not require energy.
• Movement down the concentration gradient.
• Examples
• Diffusion
• Osmosis
• Facilitated diffusion

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Passive vs. Active Transport

• Active Transport
• Requires energy.
• Movement against the concentration gradient.
• Examples
• Sodium-potassium pump
• Endocytosis
• Phagocytosis
• Pinocytosis
• Exocytosis

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Fig. 5-1a
Carbohydrate of glycoprotein
Glycoprotein
Glycolipid
Integrin
Phospholipid
Microfilaments of cytoskeleton
Cholesterol
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ATP

• The energy currency of the cell.
• An organic molecule that acts as the main energy
  source for cell processes
• Composed of a nitrogen base, a sugar 3
  phosphate groups.
• The energy is stored in the phosphate bonds.
• Powers metabolism.

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Photosynthesis

• Process by which plants, algae some bacteria
  use sunlight, CO2 H2O to produce carbohydrates
  O2.
• Takes place in the chloroplast
• Main pigment is chlorophyll.
• Reactants are CO2 and H2O
• End products are glucose O2

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Photosynthesis

• Stage 1
• Consists of the absorption of light energy which
  excites the electrons in chlorophyll.
• The electrons enter the ETC (electron transport
  chain).
• Water is split to produce O2, H, and the
  electrons to replace those lost by the
  chlorophyll molecules.

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Photosynthesis

• Stage 2
• The conversion of light energy into chemical
  energy that is temporarily stored in ATP and
  NADPH.
• The energy from ATP and NADPH will be used to
  power the third stage.

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Photosynthesis

• Stage 3
• CO2 fixation occurs
• Inorganic CO2 is fixed into organic compounds
  (sugars).

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Cellular Respiration

• Process by which cells produce energy from
  carbohydrates O2 combines w/ glucose to form H2O
  CO2.
• Takes place in the mitochondrion.
• Reactants are glucose and oxygen.
• Products are carbon dioxide water.

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Aerobic Respiration vs. Anaerobic Respiration

• Aerobic Respiration
• Requires oxygen.
• Produces much more ATP (38 net ATP)
• Anaerobic Respiration
• Does not require oxygen.
• Regenerates NAD so that gylcolysis can continue.
  
• (2 net ATP from glycolysis)

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Aerobic Respiration

• Stage 1 Glycolysis takes place in the
  cytoplasm.
• Does not require oxygen.
• Glucose is broken down to 2 pyruvate molecules
• Produces 2 net ATP and 2 NADH
• Stage 2 Bridge reaction carries pyruvates into
  the mitochondrion.
• 2 CO2 and 2 NADH are produced

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Aerobic Respiration

• Stage 3 Krebs Cycle occurs in the matrix of the
  mitochondrion
• In the presence of oxygen.
• In two turns of the Krebs Cycle
• 4 CO2 are produced
• 6 NADH are produced
• 2 ATP are produced
• 2 FADH2 are produced.

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Aerobic Respiration

• Stage 4 Electron Transport Chain occurs in the
  inner membrane of the mitochondrion
• In the presence of oxygen.
• 34 net ATP produced
• 2NADH from glycolysis 6ATP
• 2 NADH from bridge reaction 6 ATP
• 6 NADH from Krebs cycle 18 ATP
• 2 FADH2 from Krebs cycle 4ATP

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Anaerobic Respiration or Fermentation

• Alcoholic Fermentation
• Occurs in the absence of oxygen
• Occurs in yeast and some bacteria
• Produces
• Ethyl alcohol
• Carbon dioxide
• Regenerates NAD so glycolysis can continue

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Anaerobic Respiration or Fermentation

• Lactic Acid Fermentation
• Occurs in the absence of oxygen
• Occurs in the muscle tissue of animals in
  lactic acid bacteria
• Produces
• Lactic acid
• Regenerates NAD so glycolysis can continue

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Atom and Its Parts

• An atom is the smallest unit of an element that
  maintains the properties of that element.
• Nucleus contains
• Proton ()
• Neutron (Neutral)
• Electron cloud
• Electron ()

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Covalent vs. Ionic Bonds

• Covalent Bond
• Bond formed when atoms share pairs of electrons.
• Ionic Bond
• Bond formed by the attraction between oppositely
  charged ions.

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Covalent vs. Ionic Bonds
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Molecules and Polar Molecules

• Molecule
• A group of atoms held together by covalent bonds.
  
• Polar Molecule
• Shares its electrons unequally and therefore has
  partially positive and negative ends, or poles.
• Water is a polar molecule.

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Molecules and Polar Molecules
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Solvents

• Solvent
• A substance, usually a liquid, capable of
  dissolving another substance.
• Universal Solvent
• Water.

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pH Scale and Acids Bases

• pH Scale ranges from 0 - 14
• Acid
• A compound that forms hydrogen ions (H) in
  water.
• Its pH is 0 to less than 7. (0 to lt 7)
• Base
• A compound that forms hydroxide ions (OH-) in
  water.
• Its pH is greater than 7 to 14. (gt7 to 14)
• Neutral
• Substances that have a pH of 7.

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Organic Macromolecules

• Organic macromolecules
• Contain carbon atoms that are covalently bonded
  to other elements typically hydrogen, oxygen
  and other carbon atoms.
• 4 principal classes of organic compounds found in
  living things are
• Carbohydrates
• Lipids
• Proteins
• Nucleic acids

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Organic Macromolecules

• Carbohydrates organic compounds made of carbon,
  hydrogen and oxygen in a 121 ratio.
• Monomers are monosaccharides.
• Ex Glucose and fructose
• Polymers are polysaccharides.
• Ex Starches, potatoes, paper, crab shells
• Functions
• Stores energy.
• Makes up cell walls in plants and fungi.
• Makes up exoskeleton in some animals.

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Organic Macromolecules

• Lipids are nonpolar molecules that are insoluble
  in water include fats, phospholipids, steroids
  and waxes.
• Monomers are glycerol fatty acids
• Polymer examples
• Butter oil
• All membranes
• Cholesterol and Steroids
• Functions
• Stores energy
• Makes up cell membranes
• Acts as chemical messengers

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Organic Macromolecules

• Proteins
• Monomers are amino acids
• Polymer examples
• Hemoglobin and antibodies
• Muscle, hair and nails
• Functions
• Hemoglobin carries oxygen and antibodies help
  defend against infection.
• Make up tissues that support body structures and
  provide movement
• Speed up chemical reactions (enzymes)

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Organic Macromolecules

• Nucleic acids
• Monomers are nucleotides
• Polymer examples
• DNA
• RNA
• Functions
• Controls cellular activities
• Stores hereditary information
• Plays key role in the manufacture of proteins

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Catalyst vs. Enzyme

• Catalyst
• Speeds up chemical reactions by lowering the
  activation energy.
• Enzyme
• Specialized protein that acts as an organic
  catalyst.

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Test Indicators Positive Results

• Benedicts solution
• Tests for simple sugars blue color changes to
  red, orange, yellow, green.
• Lugols iodine
• Tests for starch reddishorange iodine turns
  blue-black or black.
• Biuret solution
• Tests for protein blue turns purple.
• BTB (Bromthymol blue)
• Tests for CO2 blue turns green, or yellow.