Video Transcript
The graph provided shows the number of people requiring a kidney transplant compared
to the number of transplants carried out. Which of the following statements about the data correctly describes the trend? (A) The demand for kidney transplants has slowly decreased over time. (B) The number of kidney transplants carried out was higher in 1990 than in 2010. (C) The number of transplants carried out is significantly higher than the demand for
kidney transplants. Or (D) the demand for kidney transplants is consistently higher than the number of
transplants carried out.
This question is asking us to interpret a graph showing the number of people that
require a kidney transplant compared to the number of transplants that are actually
carried out. Let’s quickly review what a kidney transplant is before we take a look at the trends
shown on the graph.
The kidneys are vitally important organs within the human body, constantly filtering
blood to remove waste products and balance the concentration of ions and water. Certain conditions, like diabetes and high blood pressure, can damage the kidneys,
which can result in kidney failure. While there are some short-term solutions for kidney failure, kidney transplants
offer long-term solutions, but they require a donor with the same blood and tissue
type and can be very challenging to source.
If we take a look at the graph, we can see that the demand for kidney transplants,
represented by the red line showing the number of people on the transplant waiting
list, has steadily increased from 1990 to 2015. In 1990, there were around 6000 people on the transplant waiting list. And in 2015, this number increased to around 8000. This means we can eliminate answer option (A), which instead suggests that the demand
for kidney transplants has decreased.
The blue bars on the bottom of the graph represent the number of transplants that are
carried out each year. This number remained fairly constant around 2000 from 1990 to 2005 but then increased
slightly in 2010 and again in 2015 to almost 2500. This means that we can also eliminate answer option (B), which suggests that the
number of kidney transplants carried out was higher in 1990 than 2010, as we can see
that the number of transplants had slightly increased by 2010 and had certainly not
decreased.
In each sampled year from 1990 to 2015, the number of people on the transplant
waiting list was far higher than the number of people actually receiving kidney
transplants. For example, in 1990 around 6000 people were on the waiting list, but less than 2000
received transplants. By 2015, this gap became even larger, with 8000 people on the waiting list and less
than 2500 receiving transplants. This means that answer option (C) is incorrect too, as it states that the number of
transplants is higher than the demand.
This leaves us with answer option (D), which correctly describes the trend shown on
the graph. The demand for kidney transplants is consistently higher than the number of
transplants carried out.
