Variation

• Variation in species can be generated by genetics.
• Mutations arise spontaneously and can sometimes lead to genetic disorders or death.
• Genes can be inserted into a genome through genetic engineering.
• Genetic variation in humans can include blood group, skin colour and natural eye colour.
• Environmental causes of variation can affect the characteristics of animal and plant species, such as climate, diet, accidents, culture and lifestyle.
• Biological sex is also an inherited variation - whether you are male or female is a result of genes you inherited from your parents.
• Some features vary because of a combination of genetic and environmental causes, for example, tall parents will pass genes to their children for height, but if their diet is poor, the children will not grow very well.
• Whether you have lobed or lobeless ears is due to genetic causes.
• A zygote is a new cell formed after fertilisation, which has all the genetic information needed for an individual, known as diploid.
• Environmental variation can result in changes such as weight gain or loss, taller or shorter growth, and different flower colours in hydrangeas.
• Variation in species can be generated by genetics.
• Mutations arise spontaneously and can sometimes lead to genetic disorders or death.
• Variation in species can be generated by genetics.
• Genes can be inserted into a genome through genetic engineering.
• Mutations arise spontaneously and can sometimes lead to genetic disorders or death.
• The process of genetic engineering involves the transfer of genetic material from one organism to another.
• Genes can be inserted into a genome through genetic engineering.
• Genetic engineering has various benefits and risks, which need to be considered before its use.
• Cloning in plants and animals is a process that involves the creation of genetically identical individuals.
• Selective breeding is an artificial process in which organisms with desired characteristics are chosen as parents for the next generation.
• Extensive genetic variation is contained within any species, as evidenced by the different breeds of dogs.
• Humans have bred food crops from wild plants and domesticated animals for thousands of years.
• Variation within genes leads to different genotypes, which can be seen by different phenotypes.
• Genetic and environmental variation combine together to produce these different phenotypes.
• The main steps involved in selective breeding include deciding which characteristics are important enough to select, choosing parents that show these characteristics from a mixed population, breeding these parents together, and choosing the best offspring with the desired characteristics to produce the next generation.
• All variants arise from mutations, which are random and spontaneous changes in the structure of a gene, chromosome or number of chromosomes.
• Selective breeding takes place over many generations, with farmers repeating the process continuously until all offspring show the desired characteristics.
• Most mutations have no effect on the phenotype.
• A mutation is a change in a gene, which is the basic unit of genetic material inherited from our parents.
• A gene is a section of DNA which controls part of a cell's chemistry, particularly protein production.
• Individuals that are best adapted to their environments are more likely to survive and therefore reproduce.
• Natural selection is a process where organisms that are better adapted to an environment will survive and have more offspring, meaning their genes are passed on to the future generations.
• The peppered moth is a famous example of natural selection, where light coloured moths were no longer camouflaged and were eaten by birds, while dark moths had a better camouflage and were more likely to reproduce.
• The phenotype is the visible characteristics of an organism which occur as a result of its genes.
• The change in the proportion of dark moths until light moths became very rare in industrial areas was not due to pollution making the moths darker, but due to the dark variety having an advantage when the environment changed.
• Selective breeding is a process where organisms are bred to have specific phenotypes.
• The alleles are different forms of the same gene.
• The term 'survival of the fittest' describes how natural selection works, by selecting the best examples of an organism to survive.
• Charles Darwin, a famous English naturalist, came up with a theory of evolution during his life.
• The process of change in the inherited traits of a population of organisms from one generation to the next is known as evolution.