Material preparado por : Miss Ingrid Villa Baier
READING
COMPREHENSION WORKSHEET
Name:____________________Grade:______Date: __________________
Science: DNA Sequencing . Read the text.
(This photo was taken from :genblog.myheritage.com)
1 Scientists used to think that DNA could not be as important as it truly is . They saw the
long strands and did not understand the complexity or importance of what they were
looking at. DNA is so complex that it goes on and on and unless you know what you
are looking for you could easily get lost .
5 DNA is actually made up of several different pieces. These pieces are represented by
four different letters.
However, what people do not realize is that you would never know this unless you had open
up the helix ( which is the outer covering of a strand of DNA).
The four letters make up the building block of your cells. Despite only having four letters
10 the combinations of letters which are used are able to store a lot of information. Some of
the most important things that are created include the cells that will keep you healthy and
strong.
DNA strands develop in a specific order. As new cells are created they are spelled out by
the alphabet. This process is called a sequence. A DNA sequence is a specific type of
15 instruction for your body. You might have a sequence that explains how tall or short
you are or what color your hair should be .
There are so many sequences that if you wrote down all the combinations you would fill
up 1.000 books with the four letter combinations that make up DNA. These four letters
are A, T , G and C. The letters all stand for different things though they are often just
20 identified by letter as it is easier.
A is for adenine
C is for cytosine
G is for guanine
T is for thymine
There is one main rule to the building of DNA sequences. Adenine is only able to pair with
thymine while cytosine is only able to pair with guanine . So each combination of DNA will
either be an A with a T or a C with a G .
GENES
25 Your body contains roughly 30.000 genes. A gene is a portion of DNA that explains
something about you.
Genes are important for a number of reasons. For starters, they tell
your cells what to do. If your leg moves, your body shakes, or you raise your hand it is
because your genes have told your cells what to do.
One job of your genes is to make proteins. Over 100 proteins are working
30 inside of your body to help you function. These proteins are important because over half
of the weight of a cell is protein. Anything your body does concerning physical activity
involves the use of protein. Digestions, Circulation, Body Communication, and immunity are
just a few of the things that neeed proteins to work properly.
35 Genes cannot make protein by themselves. DNA makes RNA (Ribonucleic Acid) which is
a long strand of nucleotides. Enzymes create the RNA by copying the DNA and transcribing
the code into a new strand. The RNA is also known as messenger RNA (mRNA) The RNA
leaves the nucleus and travels into the cytoplasm of the cells. In the cytoplasm there are
ribosomes which work with the RNA to make specific proteins.
40 If you are confused about the process , all you need to remember is :
• DNA makes RNA
• RNA makes Proteins
• Proteins help your body to function.
( It was taken from Instructor WEB)
Reading Comprehension Exercises
I. Multiple Choice . Circle the right one .
1.- A person’s body is made up of cells which contain …
a) DNA
b) RNA
c) A Nucleus
d) All of the above .
2.- How many genes does our body contain?
a) 31.000 b) less than 31.000
c) more than 28.000 d) less than 30.000
3.- DNA sequencing involves DNA strand that are created with the following
letters?
a) A,C,D and F b) L,M,N, and P
c) A, C,G and T
d) None of the Above .
four
4.- The chromosomes found in a person’s cells are the product of
a) The mother and father’s genes
b) DNA
c) RNA d) Cytoplasm
II.- Fill in the Blanks .
1) The A is for …………………………………..
2) The G
if for ………………………………….
3) The T is for …………………………………..
4) The C is for …………………………………..
5) DNA
makes
……………………………………which
……………………………………….which are responsible for body functioning .
III.- Find these words in the text. What do they refer to?
1
It (line 1) _____________________
2
They (line 2) _____________________
3
These (line 5) ____________________
4
They (line 13) ____________________
5
They (line 19) ____________________
6
They (line 26) _____________________
7
Themselves (line 35 )____________________
8 which ( line 39) ________________________
makes
IV.- Read the definitions carefully. Then Join them with the right concept.
1.- a system of words, numbers, symbols that
represent a message.
2.- It is a portion of DNA
3.- to include or affect sb or sth .
………..RNA
………..combination
………..store
4.- the order that sth happens or exist in .
………..strands
5.- to put things away and keep them until you
need them
6.- a chemical substance that is produced in a
plant or animal.
7.- Ribonucleic Acid
………..involve
8.- two or more different things that exist together
or are put together.
9.- a single thin piece of thread, wire , hair, etc .
………..letter
………..code
………..sequence
……….enzimes
10.- notice that sth is happening
………..realize
11.- a sign in writing or printing that represents a
speech sound .
………. genes
Note: sb = somebody
sth = something
V.- Give the opposite of these words.
1.- important
2.- long
3.- complexity
4.- easy
5.- different
6.- outer
7.- able
8.- strong
9.- healthy
10.- inside
11.- few
12.- tall
DO YOUR BEST !