4.1 meiosis - sources of genetic variation (by jennifer)

How is variation produced in a population?

Jennifer Oh (SL)

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What is genetic variation?

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What is genetic variation?

Variation in alleles of genes

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What is genetic variation?

Variation in alleles of genes

Occurs within and among populations

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What is genetic variation?

Variation in alleles of genes

Occurs within and among populations

The “raw material” of natural selection

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Sources of Genetic Variation

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Sources of Genetic VariationMutations

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Sources of Genetic VariationMutations

Gene mutations

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Sources of Genetic VariationMutations

Gene mutations

Chromosome mutations

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Sources of Genetic VariationMutations

Gene mutations

Chromosome mutations

Sexual Reproduction

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Sources of Genetic VariationMutations

Gene mutations

Chromosome mutations

Sexual Reproduction

Recombination

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Sources of Genetic VariationMutations

Gene mutations

Chromosome mutations

Sexual Reproduction

Recombination

Mate selection

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Assessment StatementsThese are the assessment statements that deal with this topic:

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Assessment StatementsThese are the assessment statements that deal with this topic:

4.1.2 Define gene, allele, and genome

4.1.3 Define gene mutation

4.2.1 State that meiosis is a reduction division of a diploid nucleus to form haploid nuclei

4.2.3Outline the process of meiosis, including pairing of

homologous chromosomes and crossing over, followed by two divisions, which results in four haploid cells

4.3.1Define genotype, phenotype, dominant allele, recessive allele, codominant alleles, locus, homozygous, heterozygous, carrier

and test cross

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Basic Vocabulary

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Basic Vocabulary

Before diving into the details of genetic variation, here are some basic terms that you need to know for this topic.

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Basic Vocabulary

Before diving into the details of genetic variation, here are some basic terms that you need to know for this topic.

From assessment statement 4.1.2

5Tuesday, 22 November 11

Basic Vocabulary

Before diving into the details of genetic variation, here are some basic terms that you need to know for this topic.

From assessment statement 4.1.2Gene, Allele, Genome

5Tuesday, 22 November 11

Basic Vocabulary

Before diving into the details of genetic variation, here are some basic terms that you need to know for this topic.

From assessment statement 4.1.2Gene, Allele, Genome

From assessment statement 4.3.1

5Tuesday, 22 November 11

Basic Vocabulary

Before diving into the details of genetic variation, here are some basic terms that you need to know for this topic.

From assessment statement 4.1.2Gene, Allele, Genome

From assessment statement 4.3.1Genotype, phenotype

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4.1.2 Vocab

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4.1.2 Vocab

Gene - a heritable factor that controls a specific characteristic

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4.1.2 Vocab

Gene - a heritable factor that controls a specific characteristic

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4.1.2 Vocab

Gene - a heritable factor that controls a specific characteristic

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4.1.2 Vocab

Gene - a heritable factor that controls a specific characteristicAllele - one specific form of a gene, differing from other alleles by one or a few bases only and occupying the same gene locus as other alleles of the gene

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4.1.2 Vocab

Gene - a heritable factor that controls a specific characteristicAllele - one specific form of a gene, differing from other alleles by one or a few bases only and occupying the same gene locus as other alleles of the gene

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4.1.2 Vocab

Gene - a heritable factor that controls a specific characteristicAllele - one specific form of a gene, differing from other alleles by one or a few bases only and occupying the same gene locus as other alleles of the gene

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4.1.2 Vocab

Gene - a heritable factor that controls a specific characteristicAllele - one specific form of a gene, differing from other alleles by one or a few bases only and occupying the same gene locus as other alleles of the geneGenome - the whole genetic information of an organism

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4.3.1 Vocab

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4.3.1 Vocab

Genotype - the alleles of an organism; determines the genetic potential

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4.3.1 Vocab

Genotype - the alleles of an organism; determines the genetic potentialPhenotype - the characteristics of an organism

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Mutation

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Mutation

Mutations are the source of all new genetic information

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Mutation

Mutations are the source of all new genetic informationNot always harmful, some are neutral or beneficial

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Mutation

Mutations are the source of all new genetic informationNot always harmful, some are neutral or beneficialCan be accumulated over many generations

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Mutation

Mutations are the source of all new genetic informationNot always harmful, some are neutral or beneficialCan be accumulated over many generationsGene mutation (4.1.3)

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Mutation

Mutations are the source of all new genetic informationNot always harmful, some are neutral or beneficialCan be accumulated over many generationsGene mutation (4.1.3)

Change in the base sequence of an allele

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Mutation

Mutations are the source of all new genetic informationNot always harmful, some are neutral or beneficialCan be accumulated over many generationsGene mutation (4.1.3)

Change in the base sequence of an alleleChromosome mutation

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Mutation

Mutations are the source of all new genetic informationNot always harmful, some are neutral or beneficialCan be accumulated over many generationsGene mutation (4.1.3)

Change in the base sequence of an alleleChromosome mutation

Pieces of chromosomes may be rearranged during meiosis

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Mutation

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Sexual Reproduction

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Sexual ReproductionProvides rearrangement and shuffling of the genetic material into new combinations

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Sexual ReproductionProvides rearrangement and shuffling of the genetic material into new combinationsCrossing over - Recombination

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Sexual ReproductionProvides rearrangement and shuffling of the genetic material into new combinationsCrossing over - Recombination

Pieces of chromosome are often exchanged with a chromosome’s homologue

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Sexual ReproductionProvides rearrangement and shuffling of the genetic material into new combinationsCrossing over - Recombination

Pieces of chromosome are often exchanged with a chromosome’s homologueIncreases shuffling of allele combinations

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Sexual ReproductionProvides rearrangement and shuffling of the genetic material into new combinationsCrossing over - Recombination

Pieces of chromosome are often exchanged with a chromosome’s homologueIncreases shuffling of allele combinations

Mate Selection

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Sexual ReproductionProvides rearrangement and shuffling of the genetic material into new combinationsCrossing over - Recombination

Pieces of chromosome are often exchanged with a chromosome’s homologueIncreases shuffling of allele combinations

Mate SelectionDifferent combinations of genes will come together in the offspring depending on which two parents mate together

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Meiosis

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Meiosis

Meiosis is a reduction division of a diploid nucleus to form haploid nuclei (4.2.1)

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Meiosis

Meiosis is a reduction division of a diploid nucleus to form haploid nuclei (4.2.1)For this topic, the important part is: crossing over

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Meiosis

Meiosis is a reduction division of a diploid nucleus to form haploid nuclei (4.2.1)For this topic, the important part is: crossing overAt Prophase I, the homologous chromosomes pair up (synapsis), and segments of the chromosome can be exchanged

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Meiosis

Meiosis is a reduction division of a diploid nucleus to form haploid nuclei (4.2.1)For this topic, the important part is: crossing overAt Prophase I, the homologous chromosomes pair up (synapsis), and segments of the chromosome can be exchangedImportant source of variation for the gene pool of a population

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Watch this video!

GREAT video lesson about genetic variation:http://www.khanacademy.org/video/variation-in-a-species?playlist=Biology

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i-Biology Link

4.1 Presentationhttp://i-biology.net/?s=4.1

4.2 Presentationhttp://i-biology.net/?s=4.2

4.3 Presentationhttp://i-biology.net/?s=4.3

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More exercises

For more exercises on this topic, look at these pages from the Biozone workbook.

Mutations: p. 197 - 8Meiosis: p. 185 - 8Genetic Variation: p. 181 - 2

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The End!15Tuesday, 22 November 11