Year 11 students, check the dates!
In this section we will discover how the number of chromosomes are halved during meiosis and then combined with new genes from the sexual partner to produce unique offspring. Gene mutations occur continuously and on rare occasions can affect the functioning of the animal or plant. These mutations may be damaging and lead to a number of genetic disorders or death. Very rarely a new mutation can be beneficial and consequently, lead to increased fitness in the individual. Variation generated by mutations and sexual reproduction is the basis for natural selection; this is how species evolve.
An understanding of these processes has allowed scientists to intervene through selective breeding to produce livestock with favoured characteristics. Once new varieties of plants or animals have been produced it is possible to clone individuals to produce larger numbers of identical individuals all carrying the favourable characteristic.
Scientists have now discovered how to take genes from one species and introduce them in to the genome of another by a process called genetic engineering. In spite of the huge potential benefits that this technology can offer, genetic modification still remains highly controversial.
Lesson Objectives - After this topic you should know:
The main differences between asexual and sexual reproduction.
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Lesson Objectives - After this topic you should know:
How cells divide by meiosis to form gametes.
How meiosis halves the number of chromosomes in gametes and fertilisation restores the full number.
How sexual reproduction gives rise to variation.
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Lesson Objectives - After this topic you should know:
The advantages and disadvantages of asexual and sexual reproduction.
How some organisms reproduce both asexually and sexually depending on the circumstances.
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About DNA as the material of inheritance
What a genome is.
Some of the benefits of studying the human genome.
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What a nucleotide is.
More about how the structure of DNA relates to its function. (H)
How DNA controls protein synthesis.
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More about the structure of DNA and how it controls protein synthesis.
What happens in mutation.
How genes are expressed.
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That different forms of genes can be either dominant or recessive.
How to predict the results of genetic crosses when a characteristic is controlled by a single gene.
How to interpret Punnett square diagrams. (H)
How to construct Punnett square diagrams (H)
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How to use proportion and ratios to express the outcome of a genetic cross.
How sex is inherited.
How to use family trees.
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How the human genetic disorders polydactyly and cystic fibrosis are inherited.
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That embryos can be screened for some of the alleles that cause genetic disorders.
Some of the concerns and issues associated with these screening processes.
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What makes you different from the rest of your family.
Why identical twins are not the same in every way.
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How natural selection works.
How evolution occurs via natural selection.
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Lesson Objectives - After this topic you should know:
What selective breeding is.
How selective breeding works.
What the benefits and risks of selective breeding are.
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Lesson Objectives - After this topic you should know:
How genes are transferred from one organisms to another in genetic engineering to obtain the desired characteristics.
The potential benefits and problems associated with genetic engineering in agriculture and medicine.
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Different ways of creating clones.
Why clones are useful.
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How adult cell cloning is carried out.
How to explain the benefits and risks of adult cloning.
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Some of the concerns and uncertainties about the new genetic technologies such as cloning and genetic engineering.
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About the work of Gregor Mendel
How Mendel's work fits in with modern ideas about genetics
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The theory of evolution
Some of the evidence for evolution discovered by Darwin
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Objectives - After this topic you should know:
Why Darwin's theory of evolution was only gradually accepted.
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Wallace's ideas and how they influenced Darwin
How new species arise
The importance of isolation in speciation
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The evidence for the origins of life on Earth
How fossils are formed
What we can learn from fossils
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What fossils can review about how organisms have changed over time.
How organisms can become extinct.
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How environmental change can cause extinction.
How single catastrophic events can cause extinction on a massive scale.
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What is meant by antibiotic resistance
The part played by mutation in the development of antibiotic resistant strains of bacteria.
How people can reduce the rate of development of antibiotic resistant strains such as MRSA
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Objectives - After this topic you should know:
The basic principles of classification and the system developed by Linnaeus
The binomial naming system of genus and species.
How new technologies have changed classification
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Objectives - After this topic you should know:
More about the ways in which new technology has changed how scientists classify organisms
How scientists use evolutionary trees
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