Topic 6 - The Work Of Mendel

Question 1

What three important conclusions did Mendel reach about heredity in plants?

Answer 1

1) Characteristics in plants are determined by ‘hereditary units’
2) They are passed on to offspring unchanged from both parents, one unit from each
3) Hereditary units can be dominant or recessive, If both dominant - recessive, dominant will be expressed

Question 2

Why did it take people a while to understand Mendel’s work?

Answer 2

It was cutting edge and new to scientists of the day, they didn’t have the background knowledge to properly understand his findings. They didn’t know about genes, DNA or chromosmes

Question 3

How have the observations of many scientists contributed to the understanding of genes today?

Answer 3

• In the late 1800s scientists became familiar with chromosomes and observed how they behaved during cell division
• In the early 20th century they realised there were similarities in the way chromosomes and Mendel’s ‘units’ acted, and it was proposed that these units were found on the chromosomes - genes

Question 4

What allowed scientists to find out how genes worked?

Answer 4

In 1953 the structure of dna was discovered which allowed scientists to find out exactly how genes worked