How many chromatids are in twenty duplicated chromosomes

Weights of golden retriever dogs are normally distributed. samples of weights of golden retriever dogs, each of size nequals15, are randomly collected and the sample means are found. is it correct to conclude that the sample means cannot be treated as being from a normal distribution because the sample size is too small? explain.

If assuming tasting ptc as a simple gene trait,what other genotype would you select to put in this missing genotype box that could result in this phenotype

Me the formula cacl2 represents the compound