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All about your DNA (page 24)

I. Structure of DNA

a. Every __________ molecule is made in a twisted ladder called a “______________________”

b. The “sides” of the ladder are called the “____________________” of the DNA molecule

c. The backbone is made up of alternating ___________(sugar) and _______________ molecules

d. The “rungs” of the DNA ladder are made of “___________ base pairs”

e. Each rung is actually ____ individual molecules that make the rungs of the ladder.

i. _____________________

ii. _____________________

iii. _____________________

iv. _____________________

II. Nitrogen base Pairing

a. Thymine ALWAYS and ONLY bonds with _________________

b. Cytosine ALWAYS and ONLY bonds with _________________

III. Unzipping?!

a. The bonds in the middle of the “steps” of the double helix can come apart

b. Separating the Nitrogen bases “unzips” the DNA molecule

c. The DNA must be unzipped for the code to be read

IV. Genes

a. ______% of your DNA is never used for anything that we know of

b. “___________” are sections of the DNA code that are actually used by the cell to create proteins

c. Genes can be anywhere from ______ to _________ of base pairs long

V. Chromosomes

a. “________________” = _________________

b. “________________” = _________________

c. Chromosomes are coils of DNA that are wound super tight

d. Chromosomes are _____-shaped

e. Every human has ______ pairs of chromosomes-_____ in total.

i. 23 from Mom, 23 from Dad

VI. Making a Chromosome

a. Boys vs. Girls

i. The only genetic difference between males and females occurs on the ________rd

chromosome pair

ii. In _________, the 23rd pair __________ match. One chromosome, the “Y”

chromosome, is much ________________ than the other. This “_______” combination

makes the person male

iii. Females do not have the “Y”- they have two “regular” shaped chromosomes

(______).

VII. Making Boys and Girls

a. Women have __________, so they can only give an X to their offspring

b. Men have ___________. This means men have an equal chance of giving either and X or Y to

their child

c. If a male gives an X, that would create _______ (girl) when combined with the mother’s X. If

the male donates Y, that means ______ (boy) when combined with the mother’s X

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VIII. Chromosome’s Jobs

a. Chromosomes are giant _______________ of DNA, so they carry the critical

________________ for life

b. ___________ are located on Chromosomes

c. Chromosomes are the way information is passed from one _________________ to the next

d. Chromosomes are found in _____________- one from _________, one from ____________

IX. Protein Synthesis

a. Protein Synthesis = creating ____________ by reading DNA code

X. Determining Sex

a. The ________________ of a person is determined by the passing down of the “sex

chromosomes” from parents to offspring

XI. Sex-Linked Traits

a. The X and Y chromosomes have genes on them, just like all the other _____________________

b. The traits controlled by genes on these X or Y sex chromosomes are called ________________-

___________________

c. Some _________________ are sex-linked

i. All the ____________________ and _____________________ differences that make

someone a ____________ are sex-linked traits because they are passed down on the

_______ chromosome

XII. Mutation

a. Any abnormal change in an ______________________ DNA

b. If the ________________ bases aren’t kept exactly the same, large problems or changes occur.

c. If a letter simply __________________, this mutation is called a ____________________. This

is very BAD!

d. If one letter accidentally switches to a different letter, it is called a ______________________

e. If extra letters are added to the code it is called an _______________ mutation