Cells and Heredity

DNA Structure and the

Genome

Answers

DNA is a polymer made up of two strands forming a double helix. The DNA is coiled up into
structures called chromosomes which are found in the nucleus of the cell. Genes are small
sections of DNA on a chromosome. Each gene codes for a particular sequence of amino acids
that fold into a specific protein.

The chromosomes

are found in the

Nucleus of the cell.

DNA is a polymer made up of two strands forming a double helix. TheDNA is coiled up into
structures called chromosomes which are found in the nucleus of the cell.Genes are small
sections of DNA on a chromosome. Each gene codes for a particular sequence of amino acids
that fold into a specific protein.

Chromosomes are structures made of coiled up DNA.

DNA is a polymer made up of two strands forming a double helix. The DNA is coiled up into
structures called chromosomeswhich are found in the nucleus of the cell.Genes are small
sections of DNA on a chromosome. Each gene codes for a particular sequence of amino
acids that fold into a specific protein.

Genes are sections of DNA that code for a particular sequence of amino acids which will
fold into a specific protein.

DNA is a polymer made up of two strands forming a double helix. The DNA is coiled up
into structures called chromosomeswhich are found in the nucleus of the cell.Genes are small
sections of DNA on a chromosome. Each gene codes for a particular sequence of amino acids
that fold into a specific protein.

DNA is a polymer of two strands that make a

double helix.

DNA is a polymer made from four different nucleotides. Each nucleotide consists of a
phosphate group linked to a common sugar, with one of four different bases attached to the
sugar.

Bases in the
center

Adenine

Thymine

Guanine

Cystonine

DNA contains four bases, A, C, G and T. The base C is always linked to a G on the
complementary strand and an A is always linked to a T.A sequence of three bases is the
code for one particular amino acid. The order of the bases controls the order in which the
amino acids are assembled to produce a specific protein.

4. The sequence of DNA in the diagram on your paper codes for a short chain of
amino acids.

a. How many amino acids does this sequence code for? four

b. Explain your answer. Each set of three bases codes for one amino acid. There
are twelve bases. 12 ÷ 3 = 4

Explain how a mutation in this sequence could result in a change in the protein.

A mutation causes a change in a base. Since three bases code for an amino acid,
a mutation may cause a change in the amino acid that the three bases code for.
This means the sequence of amino acids would be different, so the protein will
have a different shape.

Remember when we were looking at active sites for enzymes? The shapes had to
fit just right for the process to work. If the enzyme couldn’t fit into the active site it
would not be able to function. This is the same for proteins.

Write down the definition of the word ‘genome’.

The entire genetic material of an organism