Download DNA Power Point - Chapter 4 Biology

HOW DNA WORKS
GENETICS - 7TH GRADE
HOW DNA WORKS
•Almost every cell in your body contains about 2 meters of DNA.
•DNA is found in the cells of ALL organisms.
•DNA is found in bacteria, animals, humans, even mosquitos.
UNRAVELING DNA
•DNA is often wound around proteins.
•DNA is coiled into strands and then bundled
more.
•In a cell without a nucleus – DNA is in a loop.
•In a cell with a nucleus – DNA is found in the
chromosomes.
UNRAVELING DNA
•The structure of DNA allows it to hold information.
•The order of the bases on one side of DNA is a code that
carries information.
•GENE: String of nucleotides that give cell the information
about how to make a specific trait.
•There is an ENORMOUS AMOUNT OF DNA so there is a
large variety of traits.
GENES AND PROTEINS
•The DNA code is read like a book.
•Groups of 3 bases are the codes for specific
amino acids.
PROTEINS AND TRAITS
•Proteins are found throughout cells and cause most
of the differences that you can see among
organisms.
•Proteins help determine how tall you are, what
colors you can see, and whether your hair is curly or
straight.
HELP FROM RNA
•RNA also helps make proteins.
•RNA – Ribonucleic Acid
•RNA is similar to DNA because it acts as a temporary
copy of a DNA sequence.
•LOOK AT FIGURE 2
•Brain Pop Video on RNA now. 
RNA
•Messenger RNA
sends messages to
the proteins.
•mRNA
•Transfer RNA
translates messages
for the proteins.
•tRNA