Variation and Evolution

• Variation in organisms can be achieved through cloning, genetic engineering, selective breeding, and evolution.
• The phenotype of an organism is determined by the interaction between its genotype and environment.
• Mutations cause new characteristics in organisms.
• Change in inherited characteristics over time is due to natural selection.
• Evolution can lead to the formation of new species.
• Mutations occur continuously but most do not result in a new phenotype.
• Evolution is a continuous process.
• New species are formed when organisms can no longer interbreed to produce fertile offspring.
• Different habitats have different desirable qualities, so natural selection occurs differently.
• Cloning animals involves removing the nucleus from an unfertilised egg cell and replacing it with a nucleus from an adult body cell, such as a skin cell.
• Giving an egg cell an electric shock stimulates cell division.
• Cloning is used to preserve rare plants.
• The process of genetic modification involves isolating a desirable gene using enzymes, inserting the gene into a vector (usually a bacterial plasmid or virus), and transferring the gene to the target organism early in development.
• Cloning produces offspring with identical genetic information to the parent.
• The risks of genetic modification include loss of biodiversity, high costs, and unknown long-term health impacts.
• Other cloning methods include tissue culture and cuttings for plants, and embryo transplants for animals.
• When an embryo develops, it is placed in the womb of an adult to continue developing.
• The benefits of genetic modification include improved crop yield, production of materials for medicines, and less waste.
• Genetic modification involves modifying an organism's genome to give it desirable characteristics.
• Genetically modified (GM) crops are resistant to disease, can produce better fruit, and are frost resistant.
• Genes from other organisms can be added through genetic modification.
• Bacteria have been modified to produce insulin.