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28 Cards in this Set
- Front
- Back
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Variation that can divide members of a species into two or more distinct groups |
Discrete variation |
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Three characteristics breeders would select to produce improved breeds/cultivars |
Increase in yield Disease resistance Ability to thrive in a particular environment |
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A diagram to show the probability of the inheritance of characteristics of a single gene |
Monohybrid cross |
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Phenotype |
The observed inherited characteristics |
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Genotype |
The combination of alleles inherited |
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A method for identifying an organism with an unknown genotype by crossing it with a organism that is homozygous recessive for that trait. |
Test cross |
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Variation that shows a range of variants from one extreme to another |
Continuous variation |
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The type of pattern shown when continuous variation is plotted on a distribution curve |
Normal distribution (bell shaped curve) |
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Characteristics controlled by an interaction by alleles of more than one gene |
Polygenic |
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A large scale investigation into how environmental factors affect the growth of crops |
Field trial |
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In a field trial how is bias eliminated? |
Randomising treatments (making sure replicated treatments are not applied in a pattern) |
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How is reliability ensured in a field trial? |
A number of replicates are set up |
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How do researchers ensure fair comparisons can be made between treatments in a field trial? |
A selection of treatments are applied and no other factor is varied. |
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Why is it important to repeat field trials in different environments? |
So that a more detailed conclusion can be drawn e.g. Specifically which climates a crop grows best in. |
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The fusion of two gametes from close relatives of the same species. |
Inbreeding |
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The fusion of two gametes from unrelated members of the same species. |
Outbreeding |
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The pollination of a flower with pollen from the same flower/plant |
Self pollination |
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Fertilisation of a plant ovule with pollen from another plant |
Cross pollination |
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Mechanisms cross pollinating plants have to prevent self pollination |
Anthers and ovaries maturing at different times. |
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The accumulation of recessive alleles for deleterious genes |
Inbreeding depression |
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The effects of inbreeding depression on an organisms phenotype |
Decline in vigour Lower yield Loss of fertility |
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A method for introducing new alleles to an inbred plant or animal. |
Cross breeding |
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An individual resulting from a cross between two genetically dissimilar parents of the same species |
F1 Hybrid |
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In an F1 hybrid what genotypic ratio do the F1 generation have? |
They are all heterozygous |
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What is hybrid vigour |
F1 hybrid species show increased vigour, yield and fertility. |
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What techniques can be used to maintain the F1 hybrid genotype? |
Back crossing the F1 hybrid with a parental breed and selection to remove weaker animals. Maintain the parental generation to continually cross them. |
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What modern technique can be used to identify organisms that possess alleles of a gene for a desirable characteristic? |
Genome sequencing |
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What modern technique can be used to improve a species by introducing desirable genes? |
Genetic engineering |
