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

Why might you expect to see a difference in beak length between male and female birds of the same species?

All individuals in a species always have identical beak lengths regardless of sex.

Sexual selection may favor different beak lengths in males and females due to differences in mating strategies or roles.

Environmental factors never influence beak length in birds.

Beak length differences are only caused by random mutations and never by natural selection.

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Verified step by step guidance

Understand the concept of sexual selection: Sexual selection refers to the process by which certain traits become more or less common in a population due to their impact on an individual's ability to attract mates. In this case, differences in beak length between males and females may arise if these traits are advantageous for mating strategies or roles.

Consider the role of natural selection: Natural selection can act on traits like beak length if they provide a survival or reproductive advantage. For example, males may develop longer beaks to compete for mates or access specific food resources that enhance their fitness.

Analyze environmental factors: While the problem states that environmental factors never influence beak length, this is incorrect. Environmental factors, such as food availability or habitat, can drive adaptations in beak length through natural selection, which may differ between sexes based on their ecological roles.

Evaluate the role of random mutations: Random mutations introduce genetic variation, but they are not the sole cause of differences in beak length. Natural selection acts on these mutations to favor traits that improve survival or reproduction, leading to differences between males and females.

Conclude with the interplay of sexual selection and natural selection: Differences in beak length between male and female birds of the same species are likely due to a combination of sexual selection (mating strategies) and natural selection (adaptations to environmental conditions), rather than random mutations or identical traits across all individuals.