Question 23M.1A.HL.TZ1.26
| Date | May 2023 | Marks available | [Maximum mark: 1] | Reference code | 23M.1A.HL.TZ1.26 |
| Level | HL | Paper | 1A | Time zone | TZ1 |
| Command term | Question number | 26 | Adapted from | N/A |
DNA methylation profiles in zebrafish (Danio rerio) gametes were determined. The methylated areas were divided into three groups according to the amount of methylation: high, medium and low methylation.
[Source: Potok, M.E., Nix, D.A., Parnell, T.J. and Cairns, B.R., 2013.
Reprogramming the Maternal Zebrafish Genome afterFertilization to
Match the Paternal Methylation Pattern.
Cell, [e-journal] 153(4), pp. 759–772. http://dx.doi.org/10.1016/j.
cell.2013.04.030.]
Methylation of DNA in sperm and egg is removed immediately after fertilization. What is the reason for this?
A. Methylation allows RNA polymerase to join the promoter.
B. It is needed to form homologous pairs of chromosomes.
C. It allows expression of genes linked to early development.
D. Transcription of promoters only occurs in methylated genes.
[1]
C