Table of contents

1. Introduction to Biology2h 42m
2. Chemistry3h 37m
3. Water1h 26m
4. Biomolecules2h 23m
5. Cell Components2h 26m
6. The Membrane2h 31m
7. Energy and Metabolism2h 0m
8. Respiration2h 40m
9. Photosynthesis2h 49m
10. Cell Signaling59m
11. Cell Division2h 47m
12. Meiosis2h 0m
13. Mendelian Genetics4h 44m
14. DNA Synthesis2h 27m
15. Gene Expression3h 6m
16. Regulation of Expression3h 31m
17. Viruses37m
- Viruses
  37m
18. Biotechnology2h 58m
19. Genomics17m
- Genomes
  17m
20. Development1h 5m
21. Evolution3h 1m
22. Evolution of Populations3h 53m
23. Speciation1h 37m
24. History of Life on Earth2h 6m
25. Phylogeny2h 31m
26. Prokaryotes4h 59m
27. Protists1h 12m
28. Plants1h 22m
29. Fungi36m
- Fungi
  19m
- Fungi Reproduction
  17m
30. Overview of Animals34m
- Overview of Animals
  34m
31. Invertebrates1h 2m
32. Vertebrates50m
33. Plant Anatomy1h 3m
34. Vascular Plant Transport1h 2m
- Water Potential
  1h 2m
35. Soil37m
- Soil and Nutrients
  20m
- Nitrogen Fixation
  16m
36. Plant Reproduction47m
- Flowers
  33m
- Seeds
  14m
37. Plant Sensation and Response1h 9m
38. Animal Form and Function1h 19m
39. Digestive System1h 10m
- Digestion
  1h 3m
- Blood Sugar Homeostasis
  7m
40. Circulatory System1h 49m
41. Immune System1h 12m
42. Osmoregulation and Excretion50m
- Osmoregulation and Excretion
  50m
43. Endocrine System1h 4m
- Endocrine System
  1h 4m
44. Animal Reproduction1h 2m
- Animal Reproduction
  1h 2m
45. Nervous System1h 55m
- Neurons and Action Potentials
  1h 8m
- Central and Peripheral Nervous System
  46m
46. Sensory Systems46m
- Sensory System
  46m
47. Muscle Systems23m
- Musculoskeletal System
  23m
48. Ecology3h 11m
49. Animal Behavior28m
- Animal Behavior
  28m
50. Population Ecology3h 41m
51. Community Ecology2h 46m
52. Ecosystems2h 36m
53. Conservation Biology24m
- Conservation Biology
  24m

3. Water

Properties of Water- Cohesion and Adhesion

General Biology

3. Water

Properties of Water- Cohesion and Adhesion

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Multiple Choice

Why do vinegar and oil separate in salad dressing?

Because oil is nonpolar and does not form hydrogen bonds with the polar water molecules in vinegar.

Because oil is denser than vinegar and sinks to the bottom.

Because vinegar evaporates faster than oil.

Because both vinegar and oil are polar and repel each other.

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Verified step by step guidance

Understand the chemical properties of vinegar and oil: Vinegar is primarily composed of water and acetic acid, both of which are polar molecules. Oil, on the other hand, is composed of nonpolar molecules, such as triglycerides.

Review the concept of polarity: Polar molecules have regions of partial positive and negative charges due to unequal sharing of electrons in their bonds. Nonpolar molecules lack these charged regions and do not interact well with polar molecules.

Examine the role of hydrogen bonding: Polar molecules, like those in vinegar, can form hydrogen bonds with each other. Nonpolar molecules, like oil, cannot form hydrogen bonds and therefore do not mix with polar substances.

Consider the principle of 'like dissolves like': Polar substances tend to mix with other polar substances, and nonpolar substances mix with other nonpolar substances. Since vinegar is polar and oil is nonpolar, they do not mix and instead separate.

Conclude that the separation occurs because oil is nonpolar and does not form hydrogen bonds with the polar water molecules in vinegar, leading to the two substances separating in salad dressing.