meiosis: 10 th grade
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Meiosis: 10 th Grade. Resources. Are all on the Blog!. Homework for Monday. Create a document which outlines the process of meiosis AND explains one disease that is caused by an error during meiosis Your document must be accurate, must demonstrate knowledge, and must be creative - PowerPoint PPT PresentationTRANSCRIPT
Meiosis: 10th Grade
Resources
Are all on the Blog!
Homework for Monday
Create a document which outlines the process of meiosis AND explains one disease that is caused by an error during meiosis• Your document must be accurate, must demonstrate
knowledge, and must be creative• Label AT LEAST: gene; chromosome; DNA, crossing
over and all the steps of meiosis• Provide a summary of ONE disease that results from
an error during meiosis (a non-disjunction disorder)
What is the biological purpose
of sex?
Meiosis is a two step process
• Meiosis 1 separates the homologous pairs of chromosomes: this is the reduction division
• Meiosis 2 separates the sister chromatids (resembles mitosis)
• One single diploid cell produces 4 non-identical haploid cells
Essential definitions: homologous chromosomes
• Human somatic cells have 22 homologous chromosome pairs (autosomes) and one non-homologous pair (sex chromosomes)
• One maternal/ one paternal• Same size and structure• Same genes at same loci• Alleles may differ
Essential definitions: (sister) chromatids
• Chromatid: one of two identical halves (sister chromatids) of a replicated chromosome
• NB: following crossing over, sister chromatids are no longer identical!
Essential definitions: Bivalent (tetrad)
• One pair of homologous (duplicated) chromosomes which associate during prophase 1 of meiosis
• The process of pairing is called synapsis
Getting to grips with meiosis
• Meiosis – the movie• Short summary• Fabulous website based tutorial• Step through from Sumanas
Diploid germ cell chromosomes duplicate during S phase BEFORE meiosis
Homework for Monday
Create a document which outlines the process of meiosis AND explains one disease that is caused by an error during meiosis• Your document must be accurate, must demonstrate
knowledge, and must be creative• Label AT LEAST: gene; chromosome; DNA, crossing
over and all the steps of meiosis• Provide a summary of ONE disease that results from
an error during meiosis (a non-disjunction disorder)