If you’re about to embark on GCSE Biology Paper 2 revision and need a helping hand, you’ve arrived at the right place! Beyond’s Science Team have broken down the Biology Paper 2 exam into handy bite-sized tips and tricks, helping you to boss the Biology exam in no time at all. This GCSE Biology Paper 2 revision will cover each aspect of Unit 6: Inheritance, Variation and Evolution, including:
- The Human Genome
- Genetic Engineering Advantages and Disadvantages
- Unit 6 Keywords
- Biology Paper 2 Resources from Beyond
Before you start, a brief overview of everything you need to know about Biology Unit 6 can be found in our AQA related knowledge organisers for combined science and separate biology. So you might want to download those for revision once you’ve read the text below!
Are you sitting comfortably? Good, let’s begin…
GCSE Biology Paper 2 Revision: The Human Genome
- The genome of an organism is the entire genetic material of that organism.
- Humans have 23 pairs of chromosomes. One of each set from their mum and one from their dad.
- This means that almost every cell in the human body contains 46 chromosomes.
The Human Genome Project
The project helps scientists to search for genes that are linked to different types of disease. This gives us more information on the risk of people developing the disease and might allow us to reduce the risk by encouraging lifestyle changes or interventions.
It helps us to understand and treat inherited disorders. The more we know about faulty genes, the more chance we have at developing treatments to overcome them.
We can use the information to trace human migration patterns from the past. This helps us to understand human evolution and history.
Fossils are the ‘remains’ of organisms from millions of years ago, which are found in rocks. They could take the form of:
- The actual remains of an organism that has not decayed;
- Mineralised forms of the harder parts of an organism, such as bones;
- Traces of organisms such as footprints or burrows.
An extinction occurs when there are no remaining individuals of a species still alive. This might be due to:
- Change in temperature;
- Geological changes over time;
- Catastrophic event (volcanic eruption, asteroid impact);
- New predators;
- New diseases;
- Successful competition from a new species.
GCSE Biology Paper 2 Revision: Genetic Engineering Advantages and Disadvantages
- Genetically modified (GM) crops have bigger yields and therefore have increased food value. This may help us to address an expanding population.
- Animals and plants grow faster.
- We can mass produce human proteins.
- GM crops can grow in dry, hot, cold or flooded parts of the world. This may help us to manage the effects of global warming on agriculture.
- GM crops can produce their own pesticide, can be resistant to herbicides or can contain specific nutrients.
- Models of human diseases can help us to develop treatments.
- Nobody can be sure of the long-term effects of eating GM food on human health.
- Pesticide-producing crops may result in insects developing resistance to pesticides.
- Genes from GM crops or animals could spread to species in the wild.
- People worry that this may lead to the manipulation of human genes to make ‘designer’ children.
GCSE Biology Paper 2 Revision: Evolution
- There is variation between individuals in a population.
- The individuals in a population compete for food, shelter and mates.
- Some adaptations make the individual better at competing.
- The individuals with the better adaptations are more likely to survive and reproduce.
- When they reproduce, they pass on the alleles for the useful adaptation.
Unit 6 Inheritance, Variation & Evolution Keywords
- Allele – An alternative form of a gene.
- Asexual reproduction – The production of offspring from a single parent by mitosis. The offspring are clones of the parent.
- Chromosome – Structures that contain the DNA of an organism and are found in the nucleus.
- Cystic fibrosis – A disorder of cell membranes caused by a recessive allele.
- DNA – A polymer that is made up of two strands that form a double helix.
- Dominant – An allele that is always expressed, even if only one copy is present.
- Fertilisation – The fusion of male and female gametes.
- Gamete – Sperm cell and egg cell in animals; pollen and egg cell in plants.
- Gene – A small section of DNA that codes for a specific protein.
- Genome – The entire genetic material of an organism.
- Genotype – The combination of alleles.
- Heterozygous – A genotype that has two different
- Alleles – one dominant and one recessive.
- Homozygous – A genotype that has two of the same alleles. Either two dominant alleles or two recessive alleles.
- Meiosis – The two-stage process of cell division that reduces the chromosome number of the daughter
- Embryo screening – Genetic tests carried out on an embryo to see whether it carries a faulty allele.
- Evolution – A change in the inherited characteristics of a population over time through a process of natural selection.
- Evolutionary tree – A method used to show how scientists believe organisms are related.
- Extinction – The permanent loss of all members of a species.
- Fossils – The remains of organisms from millions of years ago which are found in rocks.
- Genetic engineering – The process by which scientists manipulate and change the genotype of an organism.
- Natural selection – The process by which organisms that are better suited to an environment are more likely to survive and reproduce.
- Selective breeding – Humans selecting animals or plants, that have a required characteristic, for breeding.
- Speciation – The process by which two species evolve from a single original species by natural selection. The two populations have become so different that they can no longer interbreed to produce fertile offspring.
GCSE Biology Paper 2 Resources from Beyond
If you’re in need of some additional assistance on your road to Paper 2 excellence, try our range of revision resources below!
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