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

1. Introduction to Biology

Natural Selection and Evolution

General Biology

1. Introduction to Biology

Natural Selection and Evolution

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Multiple Choice

During his voyage on the HMS Beagle, what three types of variations among organisms did Charles Darwin observe that contributed to his theory of natural selection?

Variations in the amount of sunlight, variations in rainfall, and variations in altitude

Variations in traits among individuals, variations in traits between populations, and variations in traits over time

Variations in the number of offspring, variations in gestation period, and variations in migration patterns

Variations in climate, variations in ocean currents, and variations in soil composition

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Verified step by step guidance

Step 1: Understand the context of the question. Charles Darwin's observations during his voyage on the HMS Beagle were foundational to his theory of natural selection. He focused on biological variations among organisms rather than environmental factors like climate or soil composition.

Step 2: Recognize the types of variations that are relevant to natural selection. Darwin observed differences in traits among individuals within a population, differences in traits between populations in different locations, and changes in traits over time.

Step 3: Eliminate incorrect options. For example, variations in sunlight, rainfall, and altitude are environmental factors, not biological traits. Similarly, variations in offspring number, gestation period, and migration patterns are specific behaviors but do not encompass the broader concept of trait variations.

Step 4: Focus on the correct answer. The correct types of variations Darwin observed are: variations in traits among individuals, variations in traits between populations, and variations in traits over time. These are directly tied to the mechanisms of natural selection.

Step 5: Relate these observations to the theory of natural selection. Darwin proposed that individuals with advantageous traits are more likely to survive and reproduce, leading to the gradual evolution of populations over time. This process is driven by the variations he observed.