An Introduction about DNA, for Grade 11 students.

1. WHAT IS
DNA
Deoxyribonucleic Acid…

3. DNA or Deoxyribonucleic Acid
Is considered as the Molecular Blueprint of life.
DNA is a long, double stranded molecule that
consists of two single molecular chains wrapped
around each other. Each strand consists of a series of
bases connected to each other through a backbone of
sugar molecules. There are four different bases:
adenine, guanine, cytosine and thymine. They are
very frequently referred to simply by their first
initials: A, G, C and T. The order of those bases on a
strand of DNA is called the sequence. The sequence
on one strand of DNA is matched by a
complementary sequence on its opposite, matched
strand. A is matched with T and C is matched with G.
So where one strand of DNA has a CAATGC, the other
will have a GTTACG.

4. Blue print of life
DNA is called the blueprint of life because it
contains the instructions needed for an
organism to grow, develop, survive and
reproduce. DNA does this by controlling protein
synthesis.
Because all the information necessary to make a
living organism is stored in the DNA. No other part
of the cell contains a permanent record of how to
make a new cell, or a new tissue, or a new
organism.

5. •DNA is made up of molecules called
nucleotides. Each nucleotide contains
a phosphate group, a sugar group and
a nitrogen base. The four types of
nitrogen bases are adenine (A),
thymine (T), guanine (G) and cytosine
(C).

7. DeoxyribonucleicAcid
• DNA is compacted and packaged into
structures called CHROMOSOMES.

8. Chromosomes
•a threadlike structure of nucleic
acids and protein found in the
nucleus of most living cells, carrying
genetic information in the form of
genes.

9. Histone
• DNA double helix is first attach to
protein structures called histones. These
proteins can bind tightly to DNA.

10. Nucleosomes
• A nucleosome is a structure in your chromosomes, or
bundled DNA. Each nucleosome has a core
particle, DNA, and a linker protein. The proteins in
the core particle and linker proteins are
called histones. The DNA will wrap around the core
particle about 1.65 times and is secured by the linker
protein. This figure shows a drawing of a nucleosome.