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Genetic Variation 2.5.

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Presentation on theme: "Genetic Variation 2.5."— Presentation transcript:

1 Genetic Variation 2.5

2 Genetic Biodiversity Heredity – the passing on of characteristics from parent to offspring.

3 Genetic Biodiversity Heredity – the passing on of characteristics from parent to offspring. Gene – specific length of DNA on a chromosome that has information that determines a particular protein, which determines a characteristic/trait

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5 Genetic Biodiversity Heredity – the passing on of characteristics from parent to offspring. Gene – specific length of DNA on a chromosome that has information that determines a particular protein, which determines a characteristic/trait Alleles – alternative forms of a gene.

6 Genetic Biodiversity Heredity – the passing on of characteristics from parent to offspring. Gene – specific length of DNA on a chromosome that has information that determines a particular protein, which determines a characteristic/trait. Alleles – alternative forms of a gene. EG – a gene could be for eye colour, and the alleles are for blue eyes or brown eyes.

7 Genetic Biodiversity Heredity – the passing on of characteristics from parent to offspring. Gene – specific length of DNA on a chromosome that has information that determines a particular protein, which determines a characteristic/trait. Alleles – alternative forms of a gene. Population – members of a species living together.

8 Genetic Biodiversity Heredity – the passing on of characteristics from parent to offspring. Gene – specific length of DNA on a chromosome that has information that determines a particular protein, which determines a characteristic/trait. Alleles – alternative forms of a gene. Population – members of a species living together. Gene pool -  complete set of unique alleles in a species or population.

9 Genetic Biodiversity Heredity – the passing on of characteristics from parent to offspring. Gene – specific length of DNA on a chromosome that has information that determines a particular protein, which determines a characteristic/trait. Alleles – alternative forms of a gene. Population – members of a species living together. Gene pool -  complete set of unique alleles in a species or population. All the alleles that are present in the population.

10 Genetic Biodiversity Heredity – the passing on of characteristics from parent to offspring. Gene – specific length of DNA on a chromosome that has information that determines a particular protein, which determines a characteristic/trait. Alleles – alternative forms of a gene. Population – members of a species living together. Gene pool -  complete set of unique alleles in a species or population. All the alleles that are present in the population. Allele frequency – the number of times that an allele occurs in a population.

11 Genetic Biodiversity Overall – is about the range of different alleles present in the gene pool.

12 Genetic Biodiversity Overall – is about the range of different alleles present in the gene pool. The greater the number of different alleles, the greater the genetic biodiversity.

13 Genetic Biodiversity Overall – is about the range of different alleles present in the gene pool. The greater the number of different alleles, the greater the genetic biodiversity. Important for survival – greater range of alleles = more variation = more material for evolution to act upon.

14 Genetic Biodiversity Overall – is about the range of different alleles present in the gene pool. The greater the number of different alleles, the greater the genetic biodiversity. Important for survival – greater range of alleles = more variation = more material for evolution to act upon. With variation, when the environment changes, these favourable alleles can be selected for by natural selection.

15 Genetic Biodiversity Overall – is about the range of different alleles present in the gene pool. The greater the number of different alleles, the greater the genetic biodiversity. Important for survival – greater range of alleles = more variation = more material for evolution to act upon. With variation, when the environment changes, these favourable alleles can be selected for by natural selection. Natural selection allows the individuals with favourable alleles to cope with change (and therefore breed and pass on their ‘good’ genes)

16 Genetic Biodiversity Overall – is about the range of different alleles present in the gene pool. The greater the number of different alleles, the greater the genetic biodiversity. Important for survival – greater range of alleles = more variation = more material for evolution to act upon. With variation, when the environment changes, these favourable alleles can be selected for by natural selection. Natural selection allows the individuals with favourable alleles to cope with change (and therefore breed and pass on their ‘good’ genes) Favourable alleles often mean adaptations – changes (structure/behaviour/physiology) that enhance survival.

17 Genetic Biodiversity Overall – is about the range of different alleles present in the gene pool. The greater the number of different alleles, the greater the genetic biodiversity. Important for survival – greater range of alleles = more variation = more material for evolution to act upon. With variation, when the environment changes, these favourable alleles can be selected for by natural selection. Natural selection allows the individuals with favourable alleles to cope with change (and therefore breed and pass on their ‘good’ genes) Favourable alleles often mean adaptations – changes (structure/behaviour/physiology) that enhance survival. Individuals without fav. Alleles tend to be wiped out = frequency of ‘bad’ alleles is reduced.

18 Unfortunately… Biodiversity is not selected for in plant and animals used for humans – we want them all to be the same (strong, healthy, good breeders, tall growers, fast growers etc)

19 Unfortunately… Biodiversity is not selected for in plant and animals used for humans – we want them all to be the same (strong, healthy, good breeders, tall growers, fast growers etc) This can muck things up because the range of alleles in their gene pools can be severely limited.

20 Unfortunately… Biodiversity is not selected for in plant and animals used for humans – we want them all to be the same (strong, healthy, good breeders, tall growers, fast growers etc) This can muck things up because the range of alleles in their gene pools can be severely limited. This means that if something goes wrong (a disease usually) the whole population can be wiped out!

21 Unfortunately… Biodiversity is not selected for in plant and animals used for humans – we want them all to be the same (strong, healthy, good breeders, tall growers, fast growers etc) This can muck things up because the range of alleles in their gene pools can be severely limited. This means that if something goes wrong (a disease usually) the whole population can be wiped out! Thankfully, there are things being done to reduce this – captive breeding endangered animals in zoos, seeds stored in storage banks etc. This will ensure the gene pool has enough to continue the species.


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