DNA+Structure


 * __Chromosomes__ **

(1) Copy the diagram (& labels) near the top of page 189 ( Section 11.1 ). 

(2) Find and insert at least one YouTube (or other) video to show the structure a chromosomes. DNA Structure Animation

Another animationmedia type="custom" key="6211103"

page 190 (Section 11.2 ).
 * __DNA (deoxyribonucleic acid)__**

(3) Draw the diagram page 190 ( Section 11.2 ) to Show the link DNA → protein → Characteristic. Write a sentence to explain what this means. DNA controls production of PROTEINS which is responsible for CHARACTERISTICS

(4) What is the DNA molecule made up of? DNA is made of an alternating phosphate and sugar molecules in a linked chain. The rungs of DNA come off sugar molecules and are called bases. There are four different types of bases. They are adenine, thymine, guanine, and cytosine or A, T, G, and C. Each rung is made of two linked bases. Only certain bases can link together (A to T and G to C).  DNA’s general structure is in the form of a double helix and is primarily made up of nucleic acids. DNA is a polymer strand of nucleotides that contain sequences using genetic codes. For most complex cells, DNA is actually located in the cell nucleus.

It is a very large molecule, made up of smaller units called nucleotides that are strung together in a row, making a DNA molecule thousands of times longer than it is wide.

Each nucleotide has three parts: - Sugar molecule - A phosphate molecule - A structure called a nitrogenous base The nitrogenous base is the part of the nucleotide that carries genetic information . The bases found in the DNA come in four varieties: - Adenine - Cytosine - Guanine - Thymine These are often abbreviated as A, C, G, and T, the letters of the genetic alphabet.

(5) How many different nucleotide molecules are there? List these. There are **4** different nucleotide molecules:


 * A ** - Adenine
 * T ** - Thymine
 * G ** - Guanine
 * C ** - Cytosine


 * A ** nucleotides bind with ** T ** nucleotides.
 * G ** nucleotides bind with ** C ** nucleotides.

(6) Write a sentence to explain which bases always match up together. <span style="color: #0055ff; font-family: Arial,Helvetica,sans-serif; font-size: 10.5pt;">The nucleotides form very long 'ladders' with bases as the 'rungs' of the ladder, the base pairs are always one of two types, either adenine with thymine or //Guanine// with //Cytosine//. <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 10.5pt;"> (7) What shape is the DNA molecule (2 special words)? Draw a quick sketch (labeled) to show this shape. <span style="color: #0055ff; font-family: Arial,Helvetica,sans-serif; font-size: 10.5pt;"> The shape of a DNA molecule is called a **Double Helix** (or a "Twisted Ladder") <span style="color: #333333; font-family: 'Arial','sans-serif'; font-size: 10.5pt;">

(8) Find and insert at least one YouTube (or other) video to show the structure of DNA. media type="youtube" key="qy8dk5iS1f0" height="385" width="480"