The role of DNA in heredity A DNA molecule looks like a twisted ladder. Its shape is called a _____________ ______________.

The two sides of the DNA ladder are made of sugar molecules alternating with ____________ molecules. The rungs of the DNA molecule are made of chemical building blocks called __________. The four bases found in ______ are adenine (A), thymine (T), cytosine (C), and guanine (G).

DNA replication is the process of a DNA molecule making a ________ of itself.

DNA replication ensures that each _______________ _________has an exact copy of the DNA from the parent cell.

DNA replication Replication begins with the partial unwinding of the ___________________ ________________. The base _____________ separate. A special molecule moves along each original strand of DNA and “reads” the bases. A new strand is assembled along each original strand. (New pieces come from the __________.) The strands re-twist and two ________________ molecules are produced.

Protein synthesis In total, the DNA in one of your cells contains about 3 ________________ base pairs! The order of base pairs along a gene is called its _______ _______. What is the base sequence of this gene segment?

Protein synthesis _____________ control the production of proteins. For example, the color of your eyes is determined by a ________________. The production of proteins in the ___________ is called protein synthesis.

Protein synthesis The order of base pairs along a gene forms a _________ that tells a cell which protein to make. Sets of three bases along a strand of DNA form three-letter codes that tell the cell which ___________ __________ make up the protein. There are 20 different amino acids, so these amino acids can be put together in many ways to make __________________ of different proteins!

Protein synthesis Messenger RNA copies the gene and carries it out of the ___________________. Transfer RNA from the cytoplasm ___________________ the three letters. Transfer RNA matches the right ___________ __________ to messenger RNA sequence. The amino acids are linked together on the ribosome to form a _____________ strand.

12.1 Mutations A ______________ is a change in the hereditary material of an organism Mutations can happen in any _____ & in any gene.

12.1 Genetic disorders A genetic disorder is an abnormal condition that an organism ________ from its __________. One chromosome pair has a mutated extra chromosome. Can you find it?

12.1 Mutations Doctors use a procedure called ________________ to find out if a baby could have Down’s syndrome. The doctor removes a small amount of the fluid that surrounds the developing baby and examines the _____________________.