Thème 1 : La Terre dans l’Univers – A. Génétique et évolution Meiosis, health and evolution.. .

Background: During meiosis different events can modify the genome of the gametes. One of them is crossing over. But anomalies may also occur from time to time often leading to trouble with the baby…

Meiosis, health and evolution: • Using all the figures at your disposal, write a paragraph on meiosis

anomalies and their consequences on health and evolution Functional diagrams should explain Figure1 and Figure4…

Figure 1: Down syndrome karyotype

Figure 2: Unequal crossing over

The repetitive sequence of a chromatid may not line up exactly with its

corresponding region in a homologous

chromatid. The products of the crossing over

won’t be equal.

Figure 3: Hox genes repartition in Drosophila and

mouse Hox genes are a group of related

genes that determine the basic structure and orientation of the body

Figure 4: Hox genes comparison in an evolution

tree and their expression in the body

A big difference can be spotted between the teleost fish and

tetrapods groups and the rest of the species