Question

Flowering Locus C (FLC) is a gene that is responsible for flowering in certain plants. FLC is expressed in new seedlings, which prevents flowering. Upon exposure to cold temperatures, FLC expression decreases and the plant flowers. FLC is regulated through epigenetic modifications. What type of epigenetic modifications are present in new seedlings and after cold exposure?

a) New seedlings: Histone acetylation; After cold exposure: DNA methylation.
b) New seedlings: DNA methylation; After cold exposure: Histone acetylation.
c) New seedlings: Histone methylation; After cold exposure: Histone acetylation.
d) New seedlings: Histone acetylation; After cold exposure: Histone methylation.

Answer 1

Epigenetic modifications, such as histone acetylation and DNA methylation, regulate the flowering process in certain plants. In new seedlings, histone acetylation prevents flowering by loosening the DNA for transcription. After cold exposure, DNA methylation occurs, making it difficult to access the DNA for transcription, thus allowing the plant to flower.

Step-by-step explanation:

Epigenetic modifications play a role in the regulation of flowering locus C (FLC) gene expression. In new seedlings, histone acetylation is present, which prevents flowering. Histone acetylation loosens the DNA from the histone proteins, allowing access to the genes for transcription. However, upon exposure to cold temperatures, FLC expression decreases and the plant flowers. In this case, DNA methylation occurs as an epigenetic modification. DNA methylation adds a methyl group to the DNA, making it more difficult to access for transcription. These epigenetic modifications control FLC expression and ultimately regulate the flowering process in certain plants.