Which of the following statements is/are true of long noncoding RNAs? Choose one or more: a. They can trigger the activity of histone acetyltransferases. b. They can silence genes by promoting the formation of euchromatin. c. They are involved in X chromosome inactivation. d. They can regulate the translation and stability of mRNAs.

Options A, B, C and D are correct.

Explanation: They can trigger the activity of histone acetyltransferases.

These RNAs functions by binding to histone-modifying complexes, to DNA binding proteins (including transcription factors), and even to RNA polymerase II.

They can silence genes by promoting the formation of euchromatin by arranging hetero- or euchromatic regions into close proximity may stabilize these domains or it may control the spreading of post-translational modifications (PTMs) to nearest chromatin.

They are actively involved in X chromosome inactivation.

They can regulate the translation and stability of mRNAs.

In Eukaryotic cells RNA transcription is a closely regulated process. Transcription of a lncRNA may regulate the transcription of nearby mRNA genes, either positively (maintaining active chromatin structure) or negatively (for example, colliding polymerases). In these cases, the RNA product may have no importance at all, or it could have an additional function.

both male and female gametes are produced by meiosis of the germ cells. therefore, both male and female gametes are haploid. one male and one female gamete unite during the fertilization to form the diploid zygote. in seed bearing plants, pollen grain is the male gametophyte, which produces sperm cells.