Hey future biologists! 🌱 Ready to dive into the mesmerizing world of chromosomes and how tiny mistakes can lead to big changes? Today we're talking about Down syndrome and the concept of non-disjunction. Let's get started!

Meiosis is the cell division process that creates four haploid cells (each with half the chromosomes) from one diploid cell (a cell with a full set of chromosomes). These haploid cells become our egg and sperm cells, ready to fuse into a new life form!

Key Points

• Homologous chromosomes: Pair of similar chromosomes.
• Anaphase I: Homologous chromosomes separate and move to opposite poles.
• Anaphase II: Chromatids in each chromosome separate and move to opposite poles.

Sometimes, mistakes happen! 😬 In non-disjunction, these chromosomes or chromatids don't separate as they should. Instead, they both end up in the same daughter cell.

• Anaphase I Mistake: Both homologous chromosomes move to the same pole.
• Anaphase II Mistake: Both chromatids of a chromosome move to the same pole.

Real-world Example 🌍

Imagine a class of students splitting into teams for a basketball game, but by mistake, all the tallest kids end up on one team. That's an unfair advantage, right? Similarly, non-disjunction leads to unbalanced cells with extra or missing chromosomes.