#136 Summary of Inherited change

1 Meiosis consists of two divisions. The first division, meiosis I, separates the homologous chromosomes, so that each cell now has only one of each pair. The second division, meiosis II, separates the chromatids of each chromosome. Meiotic division therefore produces four cells, each with one complete set of chromosomes.

#135 Gene control in eukaryotes

Some genes are transcribed all the time to produce constituitive proteins; others are only 'switched on' when their protein products are required.

#134 Gene control in prokaryotes (lac operon)

In both prokaryotes and eukaryotes, transcription of a gene is controlled by transcription factors.

#133 Genetic mutations

A mutation is an unpredictable change in the genetic material of an organism.

#132 Genetic diagrams

Patterns of inheritance are explained by using genetic diagrams. Genetic diagrams are the standard way of showing the genotypes of offspring that might be expected from 2 parents.

#131 Terms for human genetics

Studies of human genetic conditions have revealed the links between genes, enzymes and the phenotypes.

#130 Meiosis

Meiosis involves two divisions, called meiosis I and meiosis II.

#129 Gametogenesis

Diploid organisms contain pairs of homologous chromosomes.

#128 Inherited Change Syllabus 2016 -2018

16.1 Passage of information from parent to offspring 
16.2 The roles of genes in determining the phenotype
16.3 Gene control