What is being taught lesson by lesson:
- Sexual and asexual reproduction.
- Meiosis and how it is different from mitosis.
- DNA and the genome.
- Genetic inheritance.
- Inherited disorders.
- Sex determination and genetic cross diagrams.
- Variation in species.
- Evolution and natural selection.
- Selective breeding.
- Genetic engineering.
- Evidence for evolution.
- Fossils and extinction.
- Resistant bacteria and MRSA.
- The classification of living organisms.
Key Terms for this topic (Tier 3 vocabulary)
Chromosomes – DNA – genes – proteins – genome – sexual reproduction – asexual reproduction – meiosis – embryo – gamete – variation – allele – characteristics – inheritance – offspring – inherited disorders – cystic fibrosis – polydactylyl – embryonic screening.
Inheritance, Variation & Evolution
Are you ready for your assessment in this topic? Try out this simple quiz.
What everyone needs to know:
How does reproduction take place? – Egg cell and sperm in animals, pollen and egg cell in plants. Some organisms reproduce aseually so there is no variation as they are genetically identical to their parent.
Need to know meiosis and how gametes are made which will give rise to genetic variation (don’t need the individual steps of meiosis). Likewise, how gametes join to make a new organism with traits from both parents.
You need to be able to describe the structure of DNA and how it relates to genes and chromosomes. You need to know the importance of knowing the human genome and how it helps understand diseases and even tracking where humans came from and migrated thousands of years ago. Know what these are: gamete, chromosome, gene, allele, dominant, recessive, homozygous, heterozygous, genotype and phenotype.
Complete simple Punnett squares to predict, for example, how many children would have a certain hair colour. Apply this for polydactyly, cystic fibrosis and even predicting sex of offspring.
Link variation and mutation to the theory of evolution by natural selection. Describe the evidence of evolution such are using the fossil record. Learn about extinction events in the past and what could happen to earth in the future.
Selective breeding and its use in increasing milk or meat production from animals, dometicated dogs, crops that are more resistant to disease and unsual plants or flowers.
This is contrasted to genetic engineering which takes a step further and in cases where bacteria have been engineered to produce insulin to treat type 1 diabetics.
There is a threat to life as bacteria mutates to become resistant to antibiotics such as MRSA. This can be linked to the reasons that doctors should not prescribe antibiotics for colds and flu.
Organisms are named by the binomial system (Carl Linnaeus) and they are classified into kingdom, phylum, class, order, family, genus and species. There are evolutionary trees that show when species have died out and where they have common ancestors.
Extra topics needed for the Higher papers:
Using punnet squares, find the likelihood of inheriting certain characteristics or even genetic diseases. This is the applied to the theory of probability.
Describe the steps in the process of genetic engineering. The use of enzymes to isolate required genes, the vector to insert a gene then placed back into cells of animals, plant or microorganisms.