Genetics
Biology: AQA GCSE Higher, topic 6.3.10
Humanity's Understanding of Genetics
Before the mid-19th century, the consensus was that sexual reproduction produced offspring that exhibited (had) a blend of characteristics. This view has evolved (changed) over time:
Mid-19th century
- Gregor Mendel, an Austrian monk, performed breeding experiments on pea plants.
- This work showed that characteristics were determined by inherited “units” passed from parents.
Late 19th century
- The first observation of how chromosomes behave during cell division.
Early 20th century
- The similarity between the behaviour of chromosomes and Mendel’s ‘units’ was recognised.
- Consequently, it was decided that the ‘units’ were located on chromosomes.
- Additionally, the ‘units’ were renamed genes.
Mid-20th century
- Technological advancements allowed scientists to work out the structure of DNA.
- The mechanism by which genes operate was also unearthed at this time.
Test yourself on Genetics
What were Gregor Mendel's inherited 'units' renamed to in the early 20th century?
Which of the following are correct about humanity's understanding of genetics?
What do Gregor Mendel's "units" appear to be similar to?
Why did scientists decide that Mendel's 'units' were located on chromosomes?
How did Mendel's pea plant experiments change the earlier belief about inheritance?