B5.2.1 Natural Selection

Question 1

Evolution

Answer 1

The gradual change of a species over time

Question 2

Natural selection

Answer 2

Process by which species best suited to their environment will survive and reproduce, passing on their advantageous characteristics to their offspring

Question 3

Survival of the fittest

Answer 3

The organisms best adapted to environment survive and reproduce, less well adapted organisms die

Question 4

Peppered moth

Answer 4

19th century Britain peppered moth = mostly pale coloured, camouflage against tress, some moths have dark coloured mutation, easily seen and eaten by birds
Industrial revolution = trees covered in soot, bark becomes black, clack coloured moths not camouflage, white ones easily seen and eaten, more black moths survived, recreated, after several years dark peppered moths became more common in urban areas

Question 5

Reproductive age

Answer 5

Age at which organism tends to reproduce

Lower age, more efficient transfer of genes as less time

Question 6

Antibiotic resisting bacteria

Answer 6

Bacteria low reproductive age, evolve within relatively short time
Occasionally have an advantageous mutation (eg, resistance to antibiotic), antibiotic doesn’t kill bacterium, bacterium reproduces, passes on resistance, eventually whole species becomes resistant

Question 7

Speciation

Answer 7

When a species adapts so much it becomes a whole new species

Could be result of: geographic isolation, random mutation

Question 8

Species

Answer 8

A group of organisms capable of breeding to produce fertile offspring