demethylation: Demethylation experiment

In smbdata: Data from "Statistical Methods in Biology"

Demethylation experiment

Description

This pilot study aimed to calibrate a scientific protocol by assessing the effect of a demethylation agent on plant phenotype. Seeds were treated with six different doses of the agent, including a zero-dose control, and then sown in trays, with each tray containing seeds treated at the same dose. Each dose was replicated across four trays: two containing 60 plants and two containing 100 plants. The experiment was arranged in a completely randomized design. For each tray, the number of plants exhibiting a normal phenotype (Normal) and the total number of plants (Total) were recorded, with each tray identified by a unique index (DTray). The dataset allows investigation of the relationship between agent dose and the binomially distributed probability of plants showing a normal phenotype.

Usage

demethylation

Format

A data frame with 4 variables: DTray, Dose, Total, Normal.

DTray

Factor. Unique identifier for each tray in the experiment.

Dose

Numeric. Dose of demethylation agent applied to the seeds (including zero for controls).

Total

Integer. Total number of plants in each tray.

Normal

Integer. Number of plants in each tray exhibiting a normal phenotype.

Source

Welham, S. J., Gezan, S. A., Clark, S. J., and Mead, A. (2015) Statistical Methods in Biology: Design and analysis of experiments and regression

Examples

glm(cbind(Normal, Total - Normal) ~ Dose,
    family = binomial(),
    data = demethylation)

glm(cbind(Normal, Total - Normal) ~ log(Dose + 0.1),
    family = binomial(),
    data = demethylation)

smbdata documentation built on Jan. 20, 2026, 5:06 p.m.