Chapter 14 lesson 3 gene regulation and expression (1 short simple sentence each)

Question

1)main idea of promoters and operators
2)detail and evidence of promoters and operators
3)main idea of transcription factors
4)main idea of cell specialization
5) detail and evidence cell specialization
6)main idea of homeotic genes
7)detail and evidence of homeotic genes
8)main idea of epigenetic
9)detail and evidence of epigenetic
10)main idea of environmental influences
11)detail and evidence of environmental influences

Questions
1)why are gene containment in compact chromatin not expressed
2)what epigenetic marker changes cause chromatin to open up

Answer 1

Chapter 14 Lesson 3: Gene Regulation and Expression

1. Main Idea of Promoters and Operators: Promoters and operators are regions of DNA that regulate the transcription of genes.

2. Detail and Evidence of Promoters and Operators: Promoters are DNA sequences where RNA polymerase binds to initiate transcription, while operators are segments that can block or allow RNA polymerase binding, influencing gene expression.

3. Main Idea of Transcription Factors: Transcription factors are proteins that help regulate gene expression by binding to specific DNA sequences.

4. Main Idea of Cell Specialization: Cell specialization refers to the process by which generic cells develop into distinct cell types with specific functions.

5. Detail and Evidence of Cell Specialization: This process involves differential gene expression, where specific genes are activated or silenced, leading to the unique functions of cells such as muscle cells and nerve cells.

6. Main Idea of Homeotic Genes: Homeotic genes control the development and body plan of organisms by determining the identity of particular body segments.

7. Detail and Evidence of Homeotic Genes: These genes contain homeoboxes, which encode proteins that regulate other genes involved in the development of anatomical structures; mutations can lead to dramatic changes in morphology.

8. Main Idea of Epigenetics: Epigenetics involves changes in gene expression that do not alter the underlying DNA sequence and can be influenced by environmental factors.

9. Detail and Evidence of Epigenetics: Modifications such as DNA methylation and histone modification can affect chromatin structure and accessibility, thereby regulating gene expression without changing the genetic code.

10. Main Idea of Environmental Influences: Environmental influences can affect gene expression and organismal development by interacting with genetic factors.

11. Detail and Evidence of Environmental Influences: Factors such as diet, temperature, and toxins can lead to epigenetic changes that modify gene expression and potentially affect an organism’s phenotype.

Questions:

1. Why are genes contained in compact chromatin not expressed?: Genes in compact chromatin are not expressed because their tightly coiled structure makes them inaccessible to the transcription machinery.

2. What epigenetic marker changes cause chromatin to open up?: Acetylation of histones and the removal of DNA methylation are epigenetic marker changes that cause chromatin to open up, facilitating gene expression.