DNA: life's code =

What does DNA mean? DNA= Deoxyribo-Nucleic Acid _____________

What's its function? DNA makes up genes that determines the ______ of all living things….such as: traits Eye color, skin color, texture, freckles, hair color, style…etc

DNA Makes up _____________ GENES Controls ____________ TRAITS CHROMOSOMES Forms _______________________ NUCLEUS Found in the __________ of all cells

...that has been __________ DNA looks like... A ladder twisted ...that has been __________ over and over. It's called a "________________" Double helix

C = CYTOSINE G = GUANINE T = THYMINE A = ADENINE The code is found in the “________” of the ladder. Each rung is a combination of ______ ________________ bonded together. The Nitrogen bases are: C = CYTOSINE G = GUANINE T = THYMINE A = ADENINE RUNGS 2 nitrogen bases

“A” bonds ONLY with “___” C G “C” bonds ONLY with “___” G A T A T G C G C C G This goes on for the entire length of the DNA molecule, which consists of __________ of nitrogen bases. T billions A

The Code The ____________________ in DNA will determine what the trait is. sequence of letters For example: Lets take a look at the letters of the alphabet… If you change the letters to “L O W” it no longer means… “O W L” means However… “A predatory bird” “A predatory bird”

DNA Code Since DNA consists of billions of nitrogen bases, the amount of variation among organisms is HUGE. If you change only one letter, the entire code will be changed, and therefore the organism will be different!!

DNA is composed of four types of nucleotides. DNA is made up of a long chain of nucleotides. Each nucleotide has three parts. 1) a phosphate group 2) a deoxyribose sugar 3) a nitrogen-containing base phosphate group deoxyribose (sugar) nitrogen-containing base

The nitrogen containing bases are the only difference in the four nucleotides.

Nucleotides always pair in the same way. The base-pairing rules show how nucleotides always pair up in DNA. A pairs with T C pairs with G Because a pyrimidine (single ring) pairs with a purine (double ring), the helix has a uniform width. C G T A

How are DNA & chromosomes related? DNA makes up a _______________. Chromosomes are found in the nucleus of every cell in the body!! chromosome

What is a gene? A gene is a ________________________that codes for a __________________. Small piece Of DNA gene specific trait 30,000 There are about __________ genes in an entire DNA molecule

Making proteins DNA RNA Protein ribosome nucleus (Physical trait) RNA is a “__________” molecule. It helps carry the DNA code to the __________ so it can make the protein. helper Skin color/texture Eye color/shape Height Bone density Hair texture Etc… ribosome DNA contains the code for what protein will be made by the cell

Questions Deoxyribo-nucleic acid T- T- C- A- G- C-- T- A- C- C- G- T- What does DNA mean? _____________________________________ Suppose one side of a DNA molecule had the bases A-A-G-T-C- G- A-T-G-G-C-A-C-C. What would the other side of the DNA look like? ____________________________________________ What is the function of RNA? _____________________________ What is a mutation? ______________________________________ What term best describes what a DNA looks like? _________________ Explain the relationship between DNA, chromosomes, and genes? __________________________________________________________ If everyone consists of only 4 nitrogen bases (A-T-C-G), why are no two people alike? __________________________________ How many chromosomes does a human have? ___________ How many genes does a human have? ___________ Therefore, approximately how many genes are on a single chromosome? ______ If 24% of a DNA molecule is Adenine, what percent would be… Thymine = ____% Guanine= _____% Cytosine= _____% T- T- C- A- G- C-- T- A- C- C- G- T- G-G carry the DNA code to the ribosome A random change in the DNA code Double helix A chromosomes is made up of DNA, which is consists of about 30,000 genes bc it’s the sequence of nitogen bases that makes us different 46 About 30,000 ~ 650 24 26 26

UNDERSTANDING THE COMPONENTS OF DNA If there is 37% of Adenine in a DNA molecule… How much Thymine? ___________ How much Cytosine? ___________ How much Guanine? ___________ If there is 23% of Guanine in a DNA molecule… How much Thymine? ___________ How much Cytosine? ___________ How much Adenine? ___________ If there is 18% of Cytosine in a DNA molecule, which is the only possibility for another nitrogen base? (Put an ‘X’ on your answer) ________18% Adenine ________64% Adenine ________ 32% Guanine ________ 32% Thymine

Replication makes an exact copy of a cell’s DNA A single strand of DNA serves as a template for a new strand. The rules of base pairing direct replication. DNA is replicated during the ____________stage of the cell cycle. Each body cell gets a complete set of identical DNA. DNA replication takes place in ___________ S (synthesis) Nucleus

Proteins carry out the process of replication. DNA serves only as a template. Enzymes and other proteins do the actual work of replication. Enzymes unzip the _______________ Free-floating nucleotides form hydrogen bonds with the template strand. Double helix nucleotide The DNA molecule unzips in both directions.

RNA carries DNA’s instructions. The central dogma states that information flows in one direction from _____________ ______________ DNA to RNA to protein

The central dogma includes three processes. 1) Replication 2) Transcription 3) Translation replication transcription translation RNA is a link between DNA and proteins.

single-stranded structure RNA differs from DNA in three major ways. 1)RNA has a ____________________ 2)RNA has ___________ instead of thymine. 3)RNA is a __________________________. Ribose sugar uracil single-stranded structure

The transcription process is similar to replication. Transcription and replication both involve complex enzymes and complementary base pairing. The two processes have different end results. Replication copies all the________; transcription copies a ___________. Replication makes _______ copy; transcription can make ________copies. growing RNA strands DNA one gene DNA gene one many

Mutations When the sequence of letters is changed. Since the code no longer reads the correct way, the cell does not make the correct protein. Consequently, a different trait may appear. They are usually _________ Oops!! bad

Some mutations affect a single gene, while others affect an entire chromosome. a change in an organism’s DNA A mutation is _______________________________. Many kinds of mutations can occur, especially during replication. A point mutation substitutes one nucleotide for another. mutated base

Many kinds of mutations can occur, especially during replication. A frameshift mutation inserts or deletes a nucleotide in the DNA sequence.

Chromosomal mutations affect many genes. Chromosomal mutations may occur during crossing over Chromosomal mutations affect many genes. Gene duplication results from unequal crossing over.

Mutations can be caused by several factors. Replication errors can cause mutations. Mutagens, such as UV ray and chemicals, can cause mutations. Some cancer drugs use mutagenic properties to kill cancer cells.

MUTATIONS CHANGE A MUTATION is any _________________ in copying the DNA message. CHANGE = WRONG ______________ A wrong base in the DNA gives the cell the wrong __________________. If a cell has the wrong message, the wrong type of ________________ is made. If the wrong protein is made, the wrong ________________ may appear. BASE PAIR MESSAGE PROTEIN TRAIT

CAUSES OF MUTATIONS Simple copying mistakes during cell reproduction A mutation causes a change in an offspring’s traits only when it takes place in the ___________________ sex cells. Chemicals _______________ Radiation PARENTS NICOTINE ASBESTOS SUN Although most mutations that change protein sequences are harmful, some mutations have a positive effect on an organism. In this case, the mutation may enable the mutant organism to withstand particular environmental stresses better than wild-type organisms, or reproduce more quickly. In these cases a mutation will tend to become more common in a population through natural selection. For example, a specific 32 base pair deletion in human CCR5 (CCR5-Δ32) confers HIV resistance to homozygotes and delays AIDS onset in heterozygotes.[35] The CCR5 mutation is more common in those of European descent. One possible explanation of the etiology of the relatively high frequency of CCR5-Δ32 in the European population is that it conferred resistance to the bubonic plague in mid-14th century Europe. People with this mutation were more likely to survive infection; thus its frequency in the population increased.[36] This theory could explain why this mutation is not found in Africa, where the bubonic plague never reached. A newer theory suggests that the selective pressure on the CCR5 Delta 32 mutation was caused by smallpox instead of the bubonic plague.[37] X-RAY __________________: Any agent that can cause alterations to DNA MUTAGEN

EFFECTS OF MUTATIONS HARMFUL MUTATIONS HELPFUL MUTATIONS Any trait that interferes with the ______________________ and _________________ of an organism. Any trait that enhances an organisms ability to______________________ and _________________ in its _____________________. REPRODUCTION REPRODUCE SURVIVAL SURVIVE ENVIRONMENT Although most mutations that change protein sequences are harmful, some mutations have a positive effect on an organism. In this case, the mutation may enable the mutant organism to withstand particular environmental stresses better than wild-type organisms, or reproduce more quickly. In these cases a mutation will tend to become more common in a population through natural selection. For example, a specific 32 base pair deletion in human CCR5 (CCR5-Δ32) confers HIV resistance to homozygotes and delays AIDS onset in heterozygotes.[35] The CCR5 mutation is more common in those of European descent. One possible explanation of the etiology of the relatively high frequency of CCR5-Δ32 in the European population is that it conferred resistance to the bubonic plague in mid-14th century Europe. People with this mutation were more likely to survive infection; thus its frequency in the population increased.[36] This theory could explain why this mutation is not found in Africa, where the bubonic plague never reached. A newer theory suggests that the selective pressure on the CCR5 Delta 32 mutation was caused by smallpox instead of the bubonic plague.[37]

CLONING The term “clone” refers to organisms having ____________________ Two “clones” are exact _______________ of each other. Same _______ = Same __________ = Same _________ Examples of clones: a. _________________: form from the splitting of _____ fertilized egg b. Clone organisms produced in ___________________ IDENTICAL DNA copies DNA GENES TRAITS IDENTICAL TWINS ONE LABORATORY

Fraternal Twins vs Identical Twins _____________________ eggs are fertilized by _____________________ sperm. Each egg and sperm carry __________________combinations of ____________. Therefore, each offspring will ________________genetically. TWO DIFFERENT TWO DIFFERENT DIFFERENT DNA VARY

Insert Nucleus from Dark frog into egg of Light frog Cloning DNA 20 20 20 20 20 Remove Body Cells Dark Green Frog Insert Nucleus from Dark frog into egg of Light frog 10 10 Remove Unfertilized Ovum Destroy Nucleus Light Green Frog

What color frog do you get? Dark Green

Dolly

DNA in Review DNA MOLECULE _______________ SIDE PARTS RUNG PARTS (SHAPE) SIDE PARTS RUNG PARTS ___________ ___________ ___________ & ___________ ___________ ___________

What is the difference between a cell, nucleus, chromosome, genes, and DNA? How are they related?

WHAT IS THE DIFFERENCE BETWEEN… Cell: ________________________________ Nucleus: ________________________________ Chromosome: _________________________________ Gene(s): _____________________________________ DNA: ________________________________________ How are they related? _____________________________ _______________________________________________