Evidence for evolution

Question 1

Describe DNA profiling

Answer 1

DNA fragments are visualised as bands
If mutations occur, enzymes will not cut the DNa changing position/size of fragments
More closely related = more bands to match

Question 2

Describe DNA and Protein sequencing

Answer 2

Compare DNA base sequence or amino acid sequence in proteins

Few differences = evolved from common ancestor more recently

Question 3

Describe DNA molecular clocks

Answer 3

As species evolve, they accumulate random mutations at a regular rate
For a given gene, mutation rate is constant
Molecular changes can be used as a molecular clock to pinpoint events in evolution

Question 4

Describe natural selection and climate change

Answer 4

Selection pressure is due to climate change

Question 5

Describe DNA hybridisation

Answer 5

DNA is gently heated to denature to 2 strands
As chimps and humans have different DNA sequences they won’t be complementary
Mix chimp and human DNA to make a hybrid
Hybrid DNA will separate at a lower temp
DNA relatedness is measured by temp needed to denature DNA
more similar bases the better they hold together ie higher temp
Use to show simililarity of genomes of 2 species