Genetics/Meiosis

In which phase does crossing-over happen?

• Prophase I

• Prophase II

• Metaphase I

• Anaphase II

What phase is this?

• Prophase I

• Metaphase II

• Anaphase I

• Telophase II

What phase is this?

• Metaphase II

• Prophase II

• Telophase I

• Anaphase I

What phase is this?

• Metaphase II

• Prophase I

• Telophase I

• Anaphase II

Chromosomes assort independantly, not genes because of the following

• The chromosomes contain the genes, genes can't leave the chromosome

• The genes contain the chromosomes

• It depends on the sex of the offspring

• In sexual selection of most organisms the genes will be directed by the DNA to assort independantly

Explain the karyotype of this individual

• Male - no genetic defect

• Male - Down's Syndrome

• Female - no genetic defect

• Female - Down's Syndrome

THIS IMAGE SHOWS WHAT IS HAPPENING WITH THE CHROMOSOMES?

• NON- DISJUNCTION

• METAPHASE

• TELOPHASE

• CROSSING OVER

The idea of non-disjunction of the 21st chromosome means the following:

• complete seperation of chromosomes

• complete seperation of genes

• failure for chromosomes to seperate

• failure for genes to seperate

WHAT DOES MEIOSIS CREATE?

• CHROMOSOMES

• GAMETES

• DNA

• TRAITS

MEIOSIS IS NEEDED BECAUSE...

• IT ACTUALLY ISN'T, BUT CAN BE HELPFUL IN SOME ORGANISMS

• TO REDUCE THE CHROMOSOME NUMBER BY HALF

• SO THAT EVERY CELL IS EXACTLY IDENTICAL

• TO MAKE SURE EVERY HUMAN CELL HAS 92 CHROMOSOMES