This defence mechanism works in many
unusable and usually gets turned off. However,
different types of bacteria, but in 2012, scientists
if scientists add in a DNA template, the proteins
figured out how to hijack CRISPR to target any
can carry out homology directed repair. This
DNA in almost any organism! In the lab, the
guide allows the rebuilding process of a
scientists first design a “guide” RNA to match
defective gene or even creation of an entirely
the gene they want to edit. They then attach the
new one.
“guide” RNA to Cas9 which tells Cas9 which
Although CRISPR is such an amazing tool, it
gene to target. Cas9 then snips the DNA which
does not always make the exact changes that
matches the “guide”. Just by attaching this
we want. This makes it difficult to predict some
“guide” RNA to Cas9, scientists can practically
of the long term effects that CRISPR gene
edit any gene in the genome.
editing will have and raises a lot of questions
After the DNA has been cut the cell tries to
about what is ethically right and wrong. But, we
repair itself by trimming the broken ends and
should always try and explore further into the
joining them back together. This type of repair
science
process is called nonhomologous end joining
potentially the key to creating cures for the
and is apparently prone to mistakes such as
genetic diseases putting many lives in danger.
behind
things
and
this
tool
is
extra or missing bases. This makes the gene
The population problem By Katherine Marriott Year 10
Scientists have spent decades pondering on how we can solve the world’s population problem. Many questions arise when answering this, is it better to have overpopulation or underpopulation? Can we really solve this problem?In the world we live in today, there are numerous problems in the field of earth's population. From insect colonisation of habitats, to poor living conditions, population can influence quality of life on any spectrum. A historical example of the problem with a country having a large population would have to be China’s infamous one child policy, which remains to be a staple in discussions on population, mainly due to the economic, social and political consequences. By 1949, China’s government sporadically began promoting family planning and the use of birth control, until after the death of Mao Zedong in 1976. Around this time China’s population was close to the 1 billion benchmark, but then under the leadership of Deng Xiaoping, pragmatic steps were taken to “solve the population problem”, in 1978 a voluntary program was introduced, with the aim to encourage families to have no more than two children. This escalated in 1979 the demand grew for families to stick to one child, however this policy was nationalised in 1980 on the 25th of September in the form of a public letter published by the central
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