understanding of genetics

Question 1

describe the development of our understanding of genetics

Answer 1

• in the mid-19th century Gregor Mendel carried out breeding experiments on plants, observing that the inheritance of
  each characteristic is determined by ‘units’ that are passed on to descendants unchanged
• late 19th century scientists observed behaviour of chromosomes during cell division
• 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.

Question 2

mendel’s 3 conclusions

Answer 2

• characteristics in plants are determined by hereditary units
• hereditary units are passed on to offspring unchanged from both parents, one unit from both parents
• hereditary units can be dominant or recessive

Question 3

what did mendel experiment on?

Answer 3

pea plants

Question 4

why was the importance of mendel’s discovery not recognised for a while?

Answer 4

• his work was new
• scientists didn’t having the background knowledge to properly understand as they had no idea about genes, DNA and chromosomes