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

13. Mendelian Genetics

Sex-Linked Inheritance

General Biology

13. Mendelian Genetics

Sex-Linked Inheritance

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Multiple Choice

Why is the number of X chromosomes crucial for sex determination in Drosophila?

The number of X chromosomes affects the expression of mitochondrial genes, which are crucial for sex determination.

The number of X chromosomes determines the ratio of X chromosomes to autosomes, which is key for sex determination.

The number of X chromosomes directly influences the production of testosterone, determining sex.

The presence of a Y chromosome is necessary for male development, regardless of the number of X chromosomes.

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Verified step by step guidance

Understand the basic concept of sex determination in Drosophila: In Drosophila, sex determination is primarily based on the ratio of X chromosomes to autosomes, rather than the presence of a Y chromosome.

Identify the role of X chromosomes: The number of X chromosomes in relation to autosomes determines the sex of the fly. A ratio of 1:1 (one X chromosome to two sets of autosomes) results in male development, while a ratio of 1:2 (two X chromosomes to two sets of autosomes) results in female development.

Clarify the misconception about mitochondrial genes: Mitochondrial genes are not directly involved in sex determination in Drosophila. The key factor is the X chromosome to autosome ratio.

Address the role of the Y chromosome: In Drosophila, the presence of a Y chromosome is not necessary for male development. Males can develop with one X chromosome and no Y chromosome, as long as the X chromosome to autosome ratio is correct.

Summarize the correct mechanism: The number of X chromosomes determines the ratio of X chromosomes to autosomes, which is crucial for sex determination in Drosophila. This ratio influences the expression of genes that control sexual development.