When James Watson and Francis Crick published the structure of DNA in _____ they added another clue to how traits are passed from parents to offspring.

DNA contains the ______ information for cells to make proteins. 

________ determine a variety of traits fro hair color to an organism's ability to digest food. 

In the early 1950's, British scientist _____________ discovered that the DNA strands are twisted around each other like coils of a spring, a shape known as a ________.

In her observations, she saw an ________ pattern indicating that there were not one, but 2 strands and the nitrogenous bases were located near the center of the DNA molecule. 

_________, an American biologist, and Frances Crick, a British ________, were also tring to understand the structure of DNA. 

The clues in Franklin's x-ray pattern enabled Watson and Crick to build a model that explained the specific structure and properties of DNA. 

The breakthrough model of DNA was a ___________, in which two strands of nucleotide sequences were wound around each other. 

Parents pass traits to their offspring through __________.

Chromosomes are made of _______________ and are located in tne nucleus of the cell. 

The twisted ladder structure of DNA is also known as a "double helix."

The sides of the double helix are made up of sugar molecules called _________, alternating with ________.

The rungs of DNA are made of __________.

___________ bases are molecules that contain nitrogen and other elements. 

DNA has 4 kinds of nitrogenous bases. 

Nitrogenous bases are: 

Austrian American biochemist ________ observed that adenosine always pairs with thymine, and guanine always pairs with cytosine. 

A _______ is a section of a DNA molecule that contains the information to code for one specific protein. 

A gene is made up fo a series of ______ in a row. 

The bases in a gene are arranged in a specific order. The order of nitrogen bases along a gene forms in a genetic code that specifies what type of protein will be produced. 

A single gene on a chromosome may contain anywhere from several hundred to a million or more bases. 

Each gene is located at a specific place on a ____________.

Because there are so many possible combinations of bases and genes, each individual organisms has a unique set of DNA. 

DNA can be found in all of the cells in your body EXCEPT for ______ cells. 

DNA can be found in blood samples; however, because _________ cells do contain DNA. 

Before the cell divides, DNA makes a _______ of itself (occurs in interphase).

__________ is the process in which an identical copy of a DNA strand is formed for a new cell. 

Replication is very important, since daughter cells need a complete set of DNA to survive. 

During replication, the DNA molecule ________ or separates into 2 strands and then produces two complementary strands following the rules of base pairing. 

Next, nitrogen bases in the nucleus pair up with the bases on each half of the DNA (A-T, C-G). 

Each strand of the double helix of DNA serves as a ___________, or model, for the new strand. 

The result is two DNA molecules ________ to each other and to the original molecule.

DNA replication is carried out by a series of __________.

Recall that enzymes are proteins with highly specific functions. The principal enzyme involved in DNA replication is called ____________.

DNA polymerase: 
1) produces the ___________ bonds that joins nucleotides together
2) "____________" each new DNA strand, so that each molecule is a near-perfect copy of the original. 

The production of a protein in a cell is called ____________.

During protein synthesis, the cells use infomration from a gene in a _________ to produces specific proteins. 

Proteins help determine the shape, color, size and other traits of an organism by triggering cellular processes. 

The protein code, pases from parent to offspring through ______, resulting in inherited traits. 

Proteins are made up of molecules called _____________.

There are _____ amino acids. 

The 20 amino acids can combine in different ways to form thousands of different ______. 

Think of the 20 amino acids as the letter of the alphabet, you combine those letters in different ways to form thousands of words. Just one change in a letter makes a different word. The same happens with proteins. 

Protein synethesis takes place in the ________ of the cell. 

Recall that chromosomes (coiled DNA strands) are located inside the _______.

Therefore, a ____________ must carry the genetic code from the nucleus to the cytoplasm in order to make those proteins. 

The genetic messenger is called: _________.

RNA has 2 strands. 

RNA contains a different sugar molecule than DNA. 

Although both RNA and DNA are nucleic acids, they have some differences.

The nitrogenous bases are somewhat different. RNA has adenine, guanine and cytosine, but instead of thymine it has ______.

There are 3 types of RNA that take part in protein synthesis. There are more RNA molecules, but they perform different functions. 

____________ copies the message from DNA in the nucleus and carries the message to the ribosomes in the cytoplasm. 

_____________ carries amino acids to the ribosomes and adds them to the growing protein. 

Some traits are not inherited from parent to offspring. Traits can also be the results of _______ in DNA. 

A ___________ is any change in the DNA of  a gene or chromosome. 

Mutations can cause cells to produce an incorrect _______ during protein synthesis and as a result the organism's trait may be different from what they would normally be. 

If a mutation occurs in a __________, such as a skin cells, the mutation will not be passed on to the organism's offspring. 

What are the three differences between DNA and RNA: 

DNA has Uracil while RNA has thymine. 

If a mutation occurs in a ________ (egg or sperm), the mutation can be passed on to an offspring and affect the offspring's traits. 

Some mutations are the result of small _____ in an organism's DNA. For example, a base pair may be added, substituted for another, or deleted from a section of DNA. 

Types of mutations in DNA include all except: 

One base pair is added. 

One base pair is removed. 

One base pair is switched for another.

Other mutations may occur when ________ don't separate correctly during the formation of sex cells. 

When this type of mutation occurs, a cell can end up with too many or too few chromosomes.Or a cell can end up with extra segments of chromosomes.

Mutations introduce change into an organism.

Mutations can be ________(negative),_________ (positive) or ________(neutral). 

A mutation is harmful if it ________ an organism's chances for survival and reproduction (albino alligator). 

Helpful mutations increase an organism's ability to survive and reproduces (bacteria mutated and become resistant to drugs). 

A mutation is _______ when it doesn't affect at all the organism. 

Cancer is not just one disease as there are more than 100 types and can occur in almost any part of the body.

Cancer affects many people around the world, regardless of age, race or gender. 

Cancers are often named for the place in the body where they begin. 

A disease in which cells grow and divide uncontrollably damaging the parts of the body around them.

Different _____ work together in determining if a person gets cancer. Some people are more prone to develop cancer because of family history. 

Some substances in the environment may also lead to cancer, like: 

Cancer begins when ________disrupt the normal cell cycle, causing cells to divide in an uncontrolled way. Without the normal controls, the cells may grow too large and divide too often. 

As the cells divide over and over, more and more abnormal cells are produced and in time form a _______. 

A mass of abnormal cells that develops when cells divide and grow uncontrollably. Cancer cells form these. 

Not all tumors are cancerous. Some are bening or non-cancerous. 

A benign tumor spreads to its surrounding healhty tissue or other parts of the body.

Othere tumors are ________, meaning that they invade and destroy surrounding healthy tissue. 

Some of the cancerous cells may break off from the tumor and enter the bloodstream and in this way spread to othera areas of the body. 

As cancer cells spread:
1) They absorb the nutrients needed by other cells
2) Block nerve connections
3) Prevent the organs they invade from funcioning correctly. 
As a results, life-threatening illness resuls. 

Some cancerous tumors can be removed by ___________.

Other tumors can be effectively treated with carefully trageted beams of ______. 

_________ is the use of chemical compounds that kills cacer cells, or at least slows down their growth. 

Because of advances in _____, DNA evidence can show many things, such as family relationshiops or the ability to produe organismas with ___________.

3 different methods for developing organisms with desired traits include all except

Process of selecting organisms with desired traits to be parents of the next generation.

People have used selective breeding with many types of animals and plants. 

2 techniques of selective breeding are: 

Technique of inbreeding involves ______ low individuals with similar desirbale characteristics.

Inbreeding produces organisma that are genetically very similar. 

When inbred organisms are mated, the chances of their offspring inheriting two ______ alleles increases. This can lead to genetic disorders. 

A ______ is an organism that has exaclty the same genes as the organism from which is was produced. 

There is _______ in some single celled organisms such as bacteria, an in humans twins are almost genetically identical. 

In __________, scientists make a copy of either an entire organisms (reproductive cloning), genes and parts of the DNA (gene cloning) or stem cells to produce tissue (therapeutic cloning). 

The first mammal to be cloned from an adult cell.

The process where genes form one organism are transferred into the DNA or another organism. 

Genetic engineering can produce _______ and improve ________.

One type of bacterium is genetically engineered to produce s human protein called _____needed by people with ______.