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Bio A level: why does expected gene numbers differ

I dont understand what my book is saying, Im doing OCR A bio dihybrid inheritance

The actual ratio of offspring produced can differ from expected. This may be because the fertilisation of gametes is a random process so in a small sample a few chance events can lead to a skewed ratio and the genes being studied are both on the same chromosome. These are known as linked genes.

I dont get what skewed ratio means and how does linked genes affect the results?

Reply 1

Kvothe the Arcane

Original post by Frank Peters

I dont understand what my book is saying, Im doing OCR A bio dihybrid inheritance

The actual ratio of offspring produced can differ from expected. This may be because the fertilisation of gametes is a random process so in a small sample a few chance events can lead to a skewed ratio and the genes being studied are both on the same chromosome. These are known as linked genes.

I dont get what a) skewed ratio means and how does b) linked genes affect the results?

a)If it's meant to be 50:50 then a skewed ratio might be 40:60.
b)linked genes are those close together on the same chromosome and thus unlikely to be separated during chromosomal crossover in meiosis I