The diagram below shows chromosomes during meiosis. how many chromosomes and chiasmata are visible

Understanding:

•  Chiasmata formation between non-sister chromatids can result in the exchange of alleles

    
Synapsis

During prophase I of meiosis, homologous chromosomes become connected in a process known as synapsis

• The connected homologues are known as a bivalent (bi = two chromosomes) or a tetrad (tetra = four chromatids)
• The chromosomes are connected by a protein-RNA complex called the synaptonemal complex
  

While autosomes always undergo synapsis during meiosis, sex chromosomes often remain unpaired

Pairing of Homologous Chromosomes via Synapsis

Chiasmata

While in synapsis, non-sister chromatids may break and recombine with their homologous partner (crossing over)

These non-sister chromatids remain physically connected at these points of exchange – regions called chiasmata

Chiasmata (singular = chiasma) hold the homologous chromosomes together as a bivalent until anaphase I

• Chiasmata formation between non-sister chromatids can result in the exchange of alleles

Electron Micrograph of Chiasmata

Skill:

•  Drawing diagrams to show chiasmata formed by crossing over

    
Chiasmata are X-shaped points of attachment between two non-sister chromatids of a homologous pair

Chiasmata form as a result of crossing over and hence non-sister chromatids should show an exchange of genetic material

• The exchange of genetic material is most easily shown if homologous chromosomes are differentially colour-coded

Chiasmata

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The diagram below shows chromosomes during meiosis.

How many chromosomes and chiasmata are visible?

There were some G2 comments on the chromosome diagram in this question. While it is not conventional, it is correct.