april science test

• An allele is different forms of the same gene
• A recessive allele is only expressed when paired with a dominant allele.
• Genetic variation occurs through mutations or changes in DNA sequences that can be passed on from one generation to another.
• A dominant allele is an alllele that will always be expressed
• A gene is the selection of DNA that controls a characteristic of an offspring
• A punnet square shows the possible combinations of alleles inheirited from each parent.
• Mutation is a change in the DNA
• Genetic modification is the altering of the genes of an organism to display desired characteristics
• Variation is different characteristics and features of two or more people
• Natural selection is when organisms adapt/evolve to an enviroment.
• characteristic means different aspects of a living thing
• adaptation is when one evolves to get used to something in order to survive
• survival of the fittest means that the best adapted organisms will survive while the rest will die
• natural selection is the process by which individuals with traits that are better suited to their environment survive and reproduce
• extinction is when there is no more individuals of a species left in the world. if a species is not adapted to its environment it will not survive
• biodiversity is the measure of the variety of different species in an ecosystem
• the cell’s nucleus contains chromosomes made from long DNA molecules
• DNA stands for deoxyribonucleic acid
• Extracting a metal from an ore


  1. Separate the iron oxide from the compounds it is mixed with

  2. Use chemical reactions to extract iron from iron oxide
• Ore is a naturally occurring rock that contains enough mineral
• The green house gases are:

  water vapour

  methane

  nitrous oxide

  carbon dioxide

  sulphur dioxide

  chlorofluro carbon
• Green house affect is the transfer of energy from the sun into the energy store of the gases in the atmosphere
• Electrolysis: if a metal is above carbon on the reactivity series, carbon is not reactive enough to displace them from their compounds. A more powerful method of extraction is needed called electrolysis
• Electrolysis is used to extract metals from their compounds
• name two human activites that increase the concentration of carbon dioxide into the atmosphere

  burning fossil fuels and farming for animals such as cows
• give an advantage of recycling

  uses less energy
• give a disadvantage of recycling

  collection lorries contribute to pollution
• why are bar charts a goodway to represent data

  because they are discrete data
• the process of extracting metals is electrolysis