B15 - Genetics And Evolution (Y11 - Spring 1)

Question 1

❌ What Did Mendel Discover

Answer 1

In the mid-19th century Gregor Mendel carried out breeding experiments on plants. He used smooth peas, wrinkled peas, green peas, and yellow peas for his work. One of his observations was that the inheritance of each characteristic is determined by ‘units’ that are passed on to descendants unchanged.

Question 2

❌ How Did Mendel Explain His Results Of His Pea Breeding Experiment

Answer 2

Mendel explained his results by suggesting there were separate units of inherited material. He realised that some characteristics were dominant over others and that they never mixed together. This was an amazing observation for a time when even chromosomes had not yet been discovered.

Question 3

❌ What Results Did Mendel End With In His Pea Breeding Experiment

Answer 3

In 1866 after Mendel recorded and analysed his work, he pubslished his findings. He explained some of the basic laws of genetics using mathematical models in ways that we use today, like the monohybrid inheritance in peas. (3:1 ratio)

Question 4

❌ What Happened After Mendel’s Work Being Released

Answer 4

Mendel’s work was never accepted until 16 years after his death (1884) as people didn’t understand his theories.

In the late 19th century behaviour of chromosomes during cell division was observed.

In the early 20th century it was observed that chromosomes and Mendel’s ‘units’ behaved in similar ways. This led to the idea that the ‘units’, now called genes, were located on chromosomes.

In the mid-20th century the structure of DNA was determined and the mechanism of gene function worked out.

This scientific work by many scientists led to the gene theory being developed.