Natural selection and Variation

Question 1

give 3 examples of genetic variation

Answer 1

eye colour, hair colour, blood group

Question 2

give 2 examples of environmental variation (animals)

Answer 2

weight of baby, growth,

Question 3

give 4 other examples of variation

Answer 3

health, intelligence, sporting ability

Question 4

what effects plant varation

Answer 4

sunlight, temperature, mineral content in soil, moisture level

Question 5

what is the theory of evolution

Answer 5

life began as simple organisms from which more complex organisms evolved

Question 6

describe the theory of natural selection

Answer 6

individuals show variation within a species due to different alleles.
individuals with more advantageous characteristics are more likely to survive (survival of the fittest), they then reproduce and pass on the advantageous traits, over many generations, the advantageous trait become more common within the species

Question 7

what is a mutation

Answer 7

a random change in an organisms sequence of DNA bases that can be inherited, they can alter the sequence of acids that produce a protien
e.g. A mutation in a gene that codes for an enzyme can change the shape of the active site, altering its function

Question 8

how can you increase the probability of a mutation

Answer 8

exposure to ionising radiation and chemicals called mutagens

Question 9

how can bacteria evolve and become antiotic-resistant

Answer 9

mutations can cause changes to bacteria’s characteristics and make it resistant.
this is advantageous as it is more likely to survive, so it lives for longer and reproduces more
this passes on the resistant allele and it becomes more common over many generations
they are called ‘superbugs’ if they are resistant to most known antibiotics