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A Reading Comprehension
Twins
Have you ever wondered what it would be like to have a brother or a sister who looked just like you?
Maybe you
are atwin. Holly and Daisy Preston, 14-year-old twins from London, say there's nothing like it.'I feel
really special, 'says Holly. Daisy agrees and adds, 'It's fantastic having someone who understands you
completely. 'If you are a twin, you probably know what they are talking about!
Scientists think twins are great, too, but for different reasons. They give scientists a unique opportunity
to find out what makes us who we are. That's because twins have more in common than brothers and
sisters born at different times, but are still different from each other in important ways. By studying the
similarities and differences between twins, scientists can begin to find out which qualities are passed
down from our ancestors and which ones result from our experiences in life.
There are two kinds of twins, known as identical and fraternal. Identical twins are often so similar that it
is difficult to tell them apart. Twins that grow inside their
mother at the same time, but are not identical, are called fraternal twins. These twins can be both boys,
both girls, or one of each.
Identical twins are interesting to scientists because of their genes, which determine the colour of their
hair and eyes, the shape of their nose and mouth, their height
and more. Most people get a different mixture of genes from their parents. That explains why you might
take after your mother, while your sister takes after your father. But with identical twins, each one gets
passed down exactly the same genes from each parent. That is what makes them'identical'.
Scientists have always wondered how important genes are. Yes, they determine which relative we look
like, but what about personality? Do our genes control whether
we like music or are outgoing? Or, are our personalities
a result of the way we grow up and the experiences we have? Interestingly, researchers have discovered
that both our genes and our experiences play a role in forming our personality. For example, you may
have a gene that makes you creative, but if your environment does not give you the chance to show
your creativity, it may never be revealed.
Identical twins can show us this relationship between genes and environment. If it were only our genes
that influenced everything about us, identical twins would be identical in every way. Not only would
they look the same, but they would like the same kinds of music, clothes and friends. But they don't.
Studying such differences can help scientists to find out what makes us the same and what makes us
different.
Exam Task Look at the sentences below about twins. Read the text to decide if each sentence is correct
or incorrect.
Write T (True) or F (False).