Organization of Genetic Material

DNA structure

IGCSE Biology

Multiple Choice

What does DNA stand for?

• Deoxyribonucleic acid
• Denitrogenous acid
• Deribonucleic acid
• Diribonucleic acid

Multiple Choice

Why is DNA important?

• it is very small and very complicated

• it's in everything

• it serves as the blueprint for traits of all living things

• because we eat it every day for energy

Multiple Choice

What does this image show?

• Double helical structure of DNA

• Triple Helical Structure of DNA

• Double helical structure of RNA

• Triple Helical Structure of RNA

Multiple Choice

DNA is a polymer made of:

• Nucleotides

• Ribosomes

• Purines

• Pyrimidines

Multiple Choice

What are the proper complementary base-pairs in nucleotides?

• A--T and G--C

• A--G and C--T

• G--T and A--C

• A--C and T--G

Multiple Choice

T A G G A C T

The complementary strand is...

• T A G G A C T

• A T G G T G A

• A T C C T G A

• T T C C A G T

Multiple Choice

What did Erwin Chargaff conclude from his experiments?

• Nitrogen bases are held together by peptide bonds
• A and T, C and G always occur in equal amounts
• Proteins are the carriers of genetic information
• C and G rarely occur in eukaryotic organisms

Can you figure out each proportion?

Multiple Choice

If there is 60% for Cytosine and Guanine combined, what is the combined % for Adenine and Thymine?

• 60%

• 40%

• 20%

• 10%

Multiple Choice

If a strand of DNA has 39% Cytosine, it has...

• 39% Adenine

• 39% Guanine

• 39% Thymine

• 39% combined Cytosine and Guanine

Multiple Choice

If there is 22% Cytosine, how much of all the other bases are there?

• 22% C, 22% G, 28% A, and 28%T

• 22% C, 28% G, 22% A, and 28%T

• 28% C, 28% G, 28% A, and 28%T

• 22% C, 22% G, 22% A, and 22%T

Multiple Choice

Which of the following correctly describes the orientation of a DNA molecule?

• a phosphate group is at the 3' end

• a phosphate group is at the 5' end

• a hydroxyl (OH) group is at the 5' end

• a water molecule is attached to the 3' end

Multiple Choice

The base pairing rules of the DNA structure allows for ___

• a consistent diameter throughout the molecule

• hydrogen bonding along the phosphate-sugar backbone

• covalent bonding between bases

• mutations to occur easilty

Open Ended

What questions do you have about DNA structure?