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
- Genetic Cloning
  9m
- Methods for Analyzing DNA
  9m
19. Cancer Genetics29m
- Overview of Cancer
  21m
- Cancer Mutations
  7m
20. Quantitative Genetics1h 26m
21. Population Genetics50m
- Hardy Weinberg
  19m
- Allelic Frequency Changes
  31m
22. Evolutionary Genetics29m

12. Gene Regulation in Prokaryotes

Lac Operon

Genetics

12. Gene Regulation in Prokaryotes

Lac Operon

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Multiple Choice

The lac operon encodes genes that are responsible for what?

Synthesizing more lactose

Breaking down lactose

Carrying lactose to the mitochondria

Converting lactose into cellulose

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Verified step by step guidance

Understand the function of the lac operon: The lac operon is a set of genes found in E. coli and other bacteria that are involved in the metabolism of lactose.

Identify the components of the lac operon: It includes three structural genes (lacZ, lacY, and lacA), a promoter, a terminator, and an operator.

Determine the role of each gene: The lacZ gene encodes β-galactosidase, which breaks down lactose into glucose and galactose. The lacY gene encodes permease, which facilitates the entry of lactose into the cell. The lacA gene encodes transacetylase, which is involved in the removal of toxic by-products of lactose digestion.

Recognize the regulatory mechanism: The lac operon is regulated by the presence or absence of lactose. In the absence of lactose, a repressor binds to the operator, preventing transcription. When lactose is present, it binds to the repressor, causing a conformational change that releases the repressor from the operator, allowing transcription.

Conclude the primary function: The lac operon is primarily responsible for breaking down lactose into simpler sugars that can be used by the cell for energy, not for synthesizing more lactose or converting it into other substances.