100 Significant Facts of Biology
Unit 1 –Biochemistry/Intro to Cells
1. Condensation reactions result in the formation of a bond between two monomers with the release of a water molecule.
2. Living things are made up of organic compounds.
3. Carbohydrates are made up of monosaccharides.
4. Glucose is stored as starch in plants and glycogen in animals.
5. Cellulose is found in the cell walls of plant cells.
6. Proteins are made of amino acids joined by peptide bonds.
7. Enzymes are proteins used to speed up chemical reactions.
8. Factors that affect enzyme function are pH, temperature, and substrate concentration.
9. During an enzyme reaction, the substrate temporarily binds to the active site.
10. Hemoglobin is a protein found in red blood cells that is used to carry oxygen to the cells.
11. Lipids are made up of 1 glycerol molecule and 3 fatty acid molecules.
12. Nucleotides are made up of a sugar, phosphate group, and nitrogen base.
13. The plasma membrane maintains homeostasis of the cell by selecting which materials are allowed in/out of the cell.
14. The cell wall is a rigid outer layer of protection for the cell.
15. Chloroplasts capture light energy for photosynthesis.
16. Vacuoles function as storage compartments in the cell and are larger in plant cells.
17. The mitochondria is responsible for energy production for the cell.
18. Ribosomes are the sites of protein synthesis.
19. A gene is a segment of DNA that codes for a protein.
20. Electron microscopes are a more powerful microscope than compound light microscopes.
21. Eukaryotic cells are complex cells containing membrane bound organelles. (ex : plant and animal cells)
22. Prokaryotic cells are small, simple cells that do not have membrane bound organelles. (ex: bacteria)
23. Prokaryotic cells contain naked DNA and/or DNA in the form of a plasmid.
24. Stem cells are unspecialized cells.
Unit 2 : Cell Processes
25. Homeostasis is maintaining a constant internal environment for an organism.
26. Active transport is the movement of particles from low to high concentration with the use of ATP.
27. Passive transport is the movement from high to low concentration without the use of ATP.
28. Diffusion is the passive transport of solutes and osmosis is the passive transport of water.
29. The plasma membrane is made up of a phospholipid bilayer.
30. The cell cycle has 5 stages: G1, S, G2, mitosis, and cytokinesis.
31. Mitosis is cell division that produces 2 identical diploid (2n) daughter cells.
32. Mitosis is a form of asexual reproduction in unicellular organisms and growth in multicellular organisms.
33. In photosynthesis, water and carbon dioxide, in the presence of light, are used to create glucose and give off oxygen.
34. In aerobic cellular respiration, oxygen and glucose are used to create ATP, give off water, and carbon dioxide.
35. All organisms undergo cellular respiration at all times.
36. Anaerobic cellular respiration occurs without oxygen present and produces less ATP along with lactic acid or ethanol.
37. Weak hydrogen bonds hold the nitrogen bases together.
38. DNA replication allows daughter cells to have an exact copy of parental DNA.
39. All cells of an organism have the same DNA, but are differentiated based on the expression of genes.
Unit 3 – Genetics/Biotechnology/Protein Synthesis
40. Gel electrophoresis is used to separate DNA segments based on size.
41. DNA fingerprinting is used to identify suspects from crime scenes, for parental identification.
42. Transgenic organisms are organisms that contain DNA from another species.
43. The Human Genome Project identified and sequenced human genes.
44. Meiosis is cell division that produces 4 haploid (n) gametes which provide genetic variation.
45. A zygote is a fertilized egg.
46. Homologous chromosomes are pairs of chromosomes that express the same trait.
47. Nondisjunction occurs during meiosis when the chromosomes fail to separate properly.
48. Crossing over occurs during meiosis when pieces of homologous chromosomes are exchanged.
49. Polygenic traits are controlled by many genes and show a variety of phenotypes (ex. skin/hair color).
50. Blood typing involves both co-dominant inheritance and multiple alleles (A,B,AB, and O).
51. Hemophilia and red-green colorblindness are sex-linked traits.
52. The normal human sex chromosomes for females are XX and for males are XY.
53. A karyotype shows a map of a person’s chromosomes.
54. Transcription and translation are the two steps in protein synthesis.
55. Transcription produces an mRNA copy of DNA.
56. Translation occurs at the ribosome when tRNA supplies the appropriate amino acids to create a protein.
57. Amino acids are linked by peptide bonds to form polypeptides, or proteins.
58. Changes in the DNA code are called mutations.
59. Mutations that occur in gametes are expressed in the offspring.
Unit 4 – Evolution/Taxonomy
60. Early Earth’s atmosphere contained water vapor, carbon dioxide, ammonia and methane, but contained no oxygen.
61. Abiogenesis states that living things arose from nonliving things while biogenesis states that only life can produce life.
62. The first organisms were prokaryotes that were anaerobic and heterotrophic.
63. Fossil evidence, anatomical structure, and biochemical similarities can indicate a common ancestor between species.
64. Natural selection states that the most fit organism will survive to reproduce.
65. Geographic and reproductive isolation results in speciation.
66. Natural selection results in antibiotic and pesticide resistance with overuse.
67. Vaccines are dead or weakened portions of the pathogen that cause active immunity.
68. Antivirals are medications that inhibit the development of viruses within a host cell.
69. Antibiotics work by breaking down prokaryotic cells.
70. Two organisms belong to the same species when they can mate and produce fertile offspring.
71. Binomial nomenclature uses the genus and species names to identify an organism.
72. A dichotomous key is used to classify organisms by their scientific name based on physical characteristics.
73. Phylogenetic trees are used to compare organisms in terms of relatedness and time of appearance in geologic history.
Unit 5 – Microbiology/Plants/Animals
74. Binary fission and conjugation are two forms of bacterial reproduction.
75. Eyespots, contractile vacuoles, cilia, flagella, and pseudopodia are all characteristics of protists.
76. Fungi gain nutrition by decomposing organic matter.
77. Root hairs increase surface area for more absorption of water and minerals by the plant.
78. Xylem is vascular tissue in a plant that transports water up from roots to leaves.
79. Phloem is vascular tissue that transports sugars down from leaves to the rest of the plant.
80. Transpiration is the loss of water from plant leaves.
81. Angiosperms are flowering plants while gymnosperms are non flowering plants.
82. The cuticle of a plant leaf is a waxy outer covering that prevents water loss.
83. Phylum Chordata includes all vertebrates such as fish, amphibians, reptiles, birds, and mammals.
84. Asexual reproduction involves one parent and no genetic variation in the offspring.
85. Sexual reproduction involves 2 parents with the offspring expressing genetic variation.
86. Innate behaviors are genetically inherited from the parents.
87. Pheromones are chemical scents animals use to communicate with each other.
88. Courtship behaviors are necessary prior to reproduction to attract and select a mate.
89. Chemotaxis is the response of organisms to a chemical stimulus in the environment and phototaxis is the response of organisms to a light stimulus in the environment.
Unit 6 - Ecology
90. In the carbon cycle, carbon dioxide is cycled in the atmosphere.
91. Excess carbon dioxide and other greenhouse gases cause the trapping of the sun’s heat close to the earth’s surface which contributes to global warming.
92. Nitrogen fixation is the process in which bacteria convert nitrogen from a gas in the air to a solid that plants use.
93. In a food chain, only 10% of energy is transferred from one organism to the next.
94. Mutualism is a relationship where both organisms benefit and parasitism is a relationship where one organism benefits while the other is harmed.
95. Competition among organisms occurs when resources are low.
96. The carrying capacity is the maximum number of organisms an ecosystem can support.
97. Bioaccumulation occurs in food chains, which allows the top consumer to ingest the highest amount of the chemical.
98. An invasive species can out-compete a native species and reduce diversity.
99. Eutrophication is the overproduction of autotrophic organisms due to excess nitrogen content.
100. Sustainability is the use of resources so that they will be available in the future.