Devonshire 2006
Year 10 Message of Life
School Certificate answers
1. DNA (the message of life) is found in the nucleus of cells. All living things are made
of cells. The answer then has to be a living thing, A.
2. Watson and Crick said that the structure of DNA was like a ladder with the matching
bases, AT and GC, like the steps on a ladder. Answer B is the correct answer.
3. Most models in science purposely simplify things to allow easier understanding. The
model for DNA is only 50 years old but that is irrelevant, if a works then it could be
100’s of years old and still be correct. The current model for DNA does allow scientists
to predict things about how DNA behaves, what it means and how it works.
C is the answer.
4. C
5. B, DNA mutation results in changes to the order of letters in the DNA, changing the
message of life. Chromosomes are made up of DNA so if the DNA changes, the
chromosome it makes up changes.
6. D, the article says ‘the virus that causes AIDS’
7. Natural selection is the process by which evolution occurs, in this case the HIV virus
has evolved to be naturally resistant to anti-retroviral drugs. C is the correct answer.
8. D is the correct answer as this is one of the ideas of natural selection, see the answer
to question 12.
9. Gene
10. Chromosome
11. Evolution
12.
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There are more offspring produced by a population than can possibly survive.
Within the offspring there is variation.
The environment determines which variation will be successful.
Unsuccessful variations cause offspring to die out before they can reproduce.
Successful variations help offspring to survive to reproduce.
The successful variations are passed onto the next generation of offspring.
Over time the entire population will have the successful variation.
Devonshire 2006
13a.
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There are more bacteria produced than can possibly survive.
Within the offspring there is variation, diagram X shows a white bacteria.
The environment (an antibiotic is added) determines which variation will be
successful.
Unsuccessful variations cause offspring to die out before they can reproduce.
The black bacteria die from the antibiotic.
Successful variations help offspring to survive to reproduce. The white bacteria
is not harmed by the antibiotic, it was ‘born’ with a mutation in its DNA that
gave it this advantage.
The successful variations are passed onto the next generation of offspring.
Over time the entire population will have the successful variation, the bacteria
are all white.
13b. DNA mutation produces variety. Some variations will be neither helpful nor
harmful, some will be harmful and some will be helpful. In an environment hat changes
it is an advantage to have variety in the population some that some will always survive.