Table of contents
- 1. Introduction to Genetics51m
- 2. Mendel's Laws of Inheritance3h 37m
- 3. Extensions to Mendelian Inheritance2h 41m
- 4. Genetic Mapping and Linkage2h 28m
- 5. Genetics of Bacteria and Viruses1h 21m
- 6. Chromosomal Variation1h 48m
- 7. DNA and Chromosome Structure56m
- 8. DNA Replication1h 10m
- 9. Mitosis and Meiosis1h 34m
- 10. Transcription1h 0m
- 11. Translation58m
- 12. Gene Regulation in Prokaryotes1h 19m
- 13. Gene Regulation in Eukaryotes44m
- 14. Genetic Control of Development44m
- 15. Genomes and Genomics1h 50m
- 16. Transposable Elements47m
- 17. Mutation, Repair, and Recombination1h 6m
- 18. Molecular Genetic Tools19m
- 19. Cancer Genetics29m
- 20. Quantitative Genetics1h 26m
- 21. Population Genetics50m
- 22. Evolutionary Genetics29m
3. Extensions to Mendelian Inheritance
Sex Chromosome
1:46 minutes
Problem 1a
Textbook Question
Textbook QuestionHow do we know that X chromosomal inactivation of either the paternal or maternal homolog is a random event during early development in mammalian females?
Verified Solution
This video solution was recommended by our tutors as helpful for the problem above
Video duration:
1mPlay a video:
Was this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
X Chromosomal Inactivation
X chromosomal inactivation is a process in female mammals where one of the two X chromosomes is randomly silenced during early embryonic development. This ensures dosage compensation, balancing the gene expression between males (XY) and females (XX). The inactivated X chromosome forms a structure known as a Barr body, which is not expressed in the cell.
Recommended video:
Guided course
09:30
X-Inactivation
Random Selection
The random selection of which X chromosome to inactivate occurs early in development, meaning that in a female's cells, some will express genes from the paternal X chromosome while others will express genes from the maternal X chromosome. This randomness is crucial for genetic diversity and can lead to mosaicism, where different cells express different alleles of X-linked genes.
Recommended video:
Guided course
07:55
Non-Random Mating
Evidence from Genetic Studies
Genetic studies, including those involving mice and humans, have shown that the inactivation of X chromosomes is random. For instance, experiments with genetically marked X chromosomes have demonstrated that the choice of which X to inactivate is independent and varies among cells, supporting the idea that this process is not influenced by the parental origin of the chromosome.
Recommended video:
Guided course
08:30
Genetics of Development
Watch next
Master Sex Determination with a bite sized video explanation from Kylia Goodner
Start learningRelated Videos
Related Practice