AQA GCSE Biology (8461), Higher tier · Inheritance, variation and evolution › Understanding of genetics and evolution
Practise Evidence for evolution. 11 exam-style questions plus unlimited generated ones on this subtopic, at up to four difficulty levels, with full mark schemes and a progress tracker. Free, no account needed.
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Complete the sentence. We now know that characteristics are passed on from parents to offspring in ..................... .
genes
Sample questions
Written for this site in the style of AQA exam questions. They are not taken from real past papers.
Question 1Easy4 marks
The theory of evolution by natural selection is now widely accepted.
(a) Which two of the following provide evidence for evolution by natural selection? Tick (✓) two boxes.[2]
Antibiotic resistance in bacteria
The fossil record
The inheritance of characteristics gained during an organism's life
The naming of organisms using the binomial system
The use of a fungus to make mycoprotein
(b) Complete the sentence. We now know that characteristics are passed on from parents to offspring in ..................... .[1]
(c) Bacteria can evolve rapidly. Give the reason why.[1]
Show the answer and mark scheme
(a)Answer: Antibiotic resistance in bacteria; The fossil record
(b)Answer: genes
genes
(c)
they reproduce at a fast rate / very quickly (so there are many generations in a short time)
Question 2Medium6 marks
An antibiotic was first used widely in 1995. {fig} shows the percentage of samples of one species of bacterium that were resistant to this antibiotic between 2000 and 2020.
[object Object]
(a) Describe the trend shown in {fig}.[2]
(b) Explain why antibiotic resistance in bacteria provides good evidence for evolution by natural selection.[3]
(c) The fossil record is another source of evidence for evolution. Give one reason why the fossil record is incomplete.[1]
Show the answer and mark scheme
(a)
the percentage of resistant bacteria increased
use of data, e.g. from 2% in 2000 to 48% in 2020
(b)
bacteria reproduce very quickly / have a short generation time
(so) changes in a population can be observed within a few years
mutations produce (new) resistant strains
resistant bacteria survive the antibiotic and reproduce, while non-resistant bacteria are killed
(so) the proportion of resistant bacteria increases, showing natural selection happening
(c)
many organisms decayed completely / were soft-bodied, so did not form fossils
many fossils have been destroyed by geological activity
many fossils have not yet been found
Question 3Hard6 marks
The theory of evolution by natural selection is supported by several types of evidence.
Describe how evidence from fossils and from antibiotic resistance in bacteria supports the theory of evolution by natural selection.[6]
Show the answer and mark scheme
fossils are the remains of organisms from millions of years ago, found in rocks
fossils in older (deeper) rock layers are generally simpler / less like present-day species than fossils in younger layers
fossils show how much or how little organisms have changed as life developed, and show species that are now extinct
the fossil record is incomplete, e.g. soft-bodied organisms rarely formed fossils and many fossils have been destroyed by geological activity
bacteria reproduce at a fast rate, so their evolution can be observed within a few years
mutations produce new strains of bacteria, and some are resistant to antibiotics
antibiotics kill non-resistant bacteria; resistant bacteria survive and reproduce, so the population of the resistant strain rises (e.g. MRSA)
this shows natural selection changing the inherited characteristics of a population
characteristics are passed on to offspring in genes, which explains how the variation is inherited
Marked with levels of response: the full level descriptors are in the app.