1. Biology Final Review

2. 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.

3. 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.

4. Autosomes vs. Sex Chromosomes

5. Gametes Gametes are an organism’s reproductive cells.
Female’s gametes are eggs or ova.
Male’s gametes are sperm.

6. 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.”

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

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

9. Karyotype
A picture of the chromosomes found in an individual’s cells at metaphase of mitosis & arranged in homologous pairs & in order of diminishing size with the sex chromosomes last.
Down’s Syndrome
is trisomy 21.

10. Parts of a Microscope

11. Microscopes and Magnification
Ocular lens x objective lens = total magnification
Magnification – making image appear larger
Resolution – clarity of image

12. 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.

13. Prokaryote vs. Eukaryote
No nucleus
No membrane bound organelles
Circular DNA
Relatively small
Reproduce quickly (20 min.)
Examples: Bacteria

14. Prokaryote vs. Eukaryote
Nucleus
Many membrane bound organelles
Linear DNA
Relatively large
Reproduce slowly (24+ hours)
Examples: Plants, animals, fungi & protists

15. Cell Parts & Functions Cell membrane Nucleus Vacuole
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.

16. Cell Parts & Functions Chloroplast Cytoplasm DNA
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.

17. Cell Parts & Functions Ribosomes Mitochondrion Cell Wall
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.

18. 5 Stages of the Cell Cycle

19. 5 Stages of the Cell Cycle
The first 3 stages are collectively called interphase. (90% of a cell’s life is spent here.)
First growth (G1) phase
Cell grows rapidly & carries out routine functions. (Major portion of a cell’s life is spent here.)

20. 5 Stages of the Cell Cycle
Synthesis (S) phase
Cell’s 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.

21. 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.

22. 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.

23. 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

24. 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.

25. 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.

26. 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.

27. 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.

28. Cytokinesis Division of the cytoplasm of a cell
Follows the division of the cell’s 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.

29. Cytokinesis
Cytokinesis in Cytokinesis in
animal cells plant cells

30. 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)

31. What are the 4 things that give rise to variation within a species?
Independent assortment
Crossing-over
Random fertilization
Mutations

32. Differentiate between spermatogenesis & oogenesis.
2 nuclear divisions in which the cytoplasm is divided equally
4 sperm produced from parent cell

33. Differentiate between spermatogenesis & 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

34. Complete the following diagrams
Process: Mitosis
Process: Meiosis

35. Compare Mitosis and Meiosis

36. 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

37. 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.

38. Diffusion vs. Osmosis Diffusion Osmosis
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.

39. Passive vs. Active Transport
Passive Transport
Does not require energy.
Movement down the concentration gradient.
Examples:
Diffusion
Osmosis
Facilitated diffusion

40. Passive vs. Active Transport
Requires energy.
Movement against the concentration gradient.
Examples:
Sodium-potassium pump
Endocytosis
Phagocytosis
Pinocytosis
Exocytosis

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

42. 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.

43. 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

44. 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.

45. 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.

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

47. 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.

48. Aerobic Respiration vs. Anaerobic 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)

49. 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

50. 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.

51. 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

52. 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

53. 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

54. 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 (–)

55. 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.

56. Covalent vs. Ionic Bonds

57. Molecules and Polar Molecules
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.

58. Molecules and Polar Molecules

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

60. pH Scale and Acids & Bases
pH Scale ranges from
Acid
A compound that forms hydrogen ions (H+) in water.
Its pH is 0 to less than 7. (0 to < 7)
Base
A compound that forms hydroxide ions (OH-) in water.
Its pH is greater than 7 to 14. (>7 to 14)
Neutral
Substances that have a pH of 7.

61. 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

62. Organic Macromolecules
Carbohydrates – organic compounds made of carbon, hydrogen and oxygen in a 1:2:1 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.

63. 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

64. 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)

65. 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

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

67. Test Indicators & Positive Results
Benedict’s solution
Tests for simple sugars – blue color changes to red, orange, yellow, green.
Lugol’s iodine
Tests for starch – reddish–orange 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.