• 12 test tubes
• Spatula
• Distilled water
• 5mL of sodium chloride
• Sodium sulfate
• Hydrochloric acid
• Sodium carbonate
• Cuprous sulfate
• Magnesum oxide
• Zinc
• Phenolphthalein
• A weighing scale

• A weighing scale
• Salt
• A teaspoon
• Beker
• Cooker

• Small paper cups (You want the smallest sized cups.)
• 1 bottle of colorless sports drink (You can also use a strong salt water solution, but “Lemon Ice” flavored Gatorade tastes better — and you can use the leftovers for refreshments after the lab!)
• Liquid dish soap (You want to use the lightest color or colorless brand you can find)
• A few drops of pineapple juice (You could also try using a quarter-teaspoon of meat tenderizer dissolved in a half-cup of water)
• 1 wood skewer (You want the kind that looks like a very long toothpick. Look in the baking aisle at the grocery store — many people use them to test cakes for doneness.)
• Alcohol (You can use regular rubbing alcohol, but if you can find 91-percent isopropyl alcohol at the drugstore get that. The closer to 100-percent alcohol you use, the better this will work.)
• Narrow container with a lid (You can use a test tube with a stopper if you have one. You could also use a small jar like you buy spices in. Make sure it is clean and dry.)

1. 24 hours before you start, put the alcohol in the kitchen freezer. Don’t worry, it won’t freeze, but it should be ice cold before you do your experiment.
2. When you are ready, take a good mouthful of sports drink and vigorously swish it around in your mouth like mouth wash. Keep going for at least 2 minutes. This takes some stamina — it’s harder than it sounds, to swish for that long! It also helps if you scrape the insides of your cheeks a little with your teeth. No blood, please; we are after the DNA from your cheek cells, not your blood type!
    
3. Spit the sports drink and cheek cell solution into a small paper cup, then pour it into your test tube or spice jar until it is about one-third full.
    
4. Add liquid dish soap until your container is about half full. Put the lid on and mix the contents by rocking the container and turning it upside down several times. Be gentle, your goal is to mix the contents but to avoid causing bubbles from the soap.
    
5. Add a few drops of pineapple juice or meat tenderizer solution. Repeat the gentle mixing.
6. Now it’s time to get that icy cold alcohol out of the freezer. Take the lid off of your cheek cell solution and tilt the container in one hand. Use your other hand to very gently trickle a small amount of alcohol down the inside of the jar so that the alcohol forms a layer floating on top of the cell solution. Return the container to its upright position and set it aside for 1 minute.
    
7. After a minute, look carefully at the place where the alcohol makes a layer floating on top of the cheek cell solution. You should see a band of white gooey material suspended between the liquid layers. Gently put the skewer down into the container so that the tip touches this material. Carefully twirl the skewer in one direction only; if you are lucky the stuff will wind around the skewer so that you can lift it out through the alcohol layer to look more closely.

• Test tubes
• Pipettes
• Salts

1) dominance: By crossing two individuals of pure lines that differ in one character you get a generation with individuals who show all the dominant character
2) segregation: in the second generation, which crosses two hybrid individuals, the recessive character reappears a lesser presence of the dominant
3) independence: by crossing two individuals that differ in two or more characters, these are transmitted independently of each other. (New phenotypes)

Genotypeis what makes the trait - the information within a gene, or the genetic makeup of a specific organism. Genotype is determined by the makeup of something called "alleles," a word that refers to the form of a gene that produces different effects.

Genotype is the information contained within two alleles. Genotype is the genetic makeup of an organism and it results in some of the physical characteristics of that organism.

Genotypes can only be determined by biological tests, not observations. Genotype is an inherited trait and hereditary information passed by the parents determines genotype. The entire genetic information about an organism is contained in a genotype – even those characteristics which are not expressed visually. 

• eye color
• hair color
• height
• how your voice sounds
• certain diseases
• certain behaviors
• the size of a bird’s beak
• the length of a fox’s tail
• the color of stripes on a cat
• the spots on a dog’s back
• a person’s shoe size

Phenotype is what you see - the visible or observable expression of the results of genes, combined with the environmental influence on an organism’s appearance or behavior. For example:

• It is the expression of gene information which is observable with the senses (like the sound of a bird’s chirping or the color of a cat’s hair)

• Eye color
• Hair color
• Height
• Sound of your voice
• Certain types of disease
• Certain behaviors
• Size of a bird’s beak
• Length of a fox’s tail
• Color of the stripes on a cat
• Size and shape of the spots on a dog’s back
• An individual’s shoe size

• La composizione chimica del DNA

• La per­cen­tua­le dei quat­tro ti­pi di nu­cleo­ti­di è sem­pre la stes­sa nel DNA di cel­lu­le pro­ve­nien­ti da tes­su­ti di­ver­si del me­de­si­mo in­di­vi­duo.
• La com­po­si­zio­ne del­le mo­le­co­le di DNA non è in­fluen­za­ta da fat­to­ri ester­ni o dal­l’e­tà del­l’or­ga­ni­smo.
• Il rap­por­to tra la per­cen­tua­le di A e quel­la di G (le due pu­ri­ne pre­sen­ti nel DNA) va­ria da una spe­cie al­l’al­tra; ciò sug­ge­ri­va una re­la­zio­ne con il «si­gni­fi­ca­to» del mes­sag­gio scrit­to nel­la bio­mo­le­co­la.
• In tut­te le spe­cie, la quan­ti­tà di ade­ni­na è ugua­le al­la quan­ti­tà di ti­mi­na (A = T) e la quan­ti­tà di gua­ni­na è ugua­le al­la quan­ti­tà di ci­to­si­na (G = C); di con­se­guen­za la quan­ti­tà to­ta­le del­le pu­ri­ne (A + G) è ugua­le a quel­la del­le pi­ri­mi­di­ne (T + C).

Gli scienziati di allora sapevano che il DNA era costituito da 4 basi diverse: adenina, timina, citosina e guanina. L'adenina (A) e la guanina (G) sono purine e la loro struttura chimica è formata da 2 anelli
La timina (T) e la citosina (C) sono pirimidine e la loro struttura chimica è formata da un singolo anello.
Erwin Chargaff  analizzò il DNA di diverse specie, spezzò le molecole di  acido desossiribonucleico nelle sue basi costitutive e le separò mediante cromatografia su carta. Queste ricerche lo portarono a formulare alcune fondamentali considerazioni sulle caratteristiche del DNA. Le regole di Chargaff  possono essere così schematizzate: La composizione in basi del DNA varia da una specie all'altra. Molecole di DNA isolate da tessuti diversi della stessa specie hanno la stessa composizione in basi. La composizione in basi del DNA di una certa specie non si modifica in base all'età, allo stato nutritivo o alle variazioni ambientali. Inoltre, in tutte le molecole di DNA, indipendentemente dalla specie:  Il numero di residui di A è uguale al numero di residui di T Il numero di residui di G è uguale al numero di residui di C La somma dei residui purinici è uguale alla somma dei residui pirimidinici Lo studio di Chargaff,  insieme agli studi successivi condotti da Rosalind Franklin e Maurice Wilkins, permetteranno a Watson e Crick di formulare il famoso modello a doppia elica del DNA

1. Ogni sospensione di batteri, tossine o virus, uccisi o vivi, ma attenuati, introducibile negli organismi a scopo profilattico e immunitario.

• Originariamente il termine indicava il vaiolo dei bovini e il pus delle pustole caratteristiche di tale malattia, impiegato in seguito per praticare l'immunizzazione contro il vaiolo umano.