BIOD 101 MODULE 3 EXAM PORTAGE LEARNING PRACTICE QUESTIONS AND RATIONALE GUIDE 2026

BIOD 101 MODULE 3 EXAM PORTAGE
LEARNING PRACTICE QUESTIONS AND
RATIONALE GUIDE 2026

◉ Contain 2 carbon-nitrogen rings, and 4 nitrogen atoms. Answer:
Purines - A and G


◉ Contain 1 carbon-nitrogen ring, and 2 nitrogen atoms. Answer:
Pyramidines - T and C


◉ Deoxyribose. Answer: sugar chemically linked to each base in
DNA


◉ Nucleoside. Answer: base + deoxyribose


◉ Nucleotide. Answer: base + deoxyribose + phosphate group


◉ complementary pairs. Answer: purine always pairs with
pyramidine
(T+A), (C+G)

, ◉ Occur when 2 negatively charged atoms share a hydrogen atom.
Answer: Hydrogen bonds


◉ # of hydrogen bonds between A and T. Answer: two


◉ # of hydrogen bonds between C and G. Answer: three


◉ sequence. Answer: specified linear arrangement of nucleotides
linked to the polynucleotide chains of DNA. Defines the entire
organism


◉ end terminating with a phosphate group. Answer: 5' (five prime)
end


◉ end terminating with a hydroxyl group. Answer: 3' (three prime)
end


◉ antiparallel arrangement. Answer: one side of the helix runs in the
opposite (5'-3') direction of the other (3'-5)


◉ Genome. Answer: entire sequence of paired bases in DNA


◉ histone proteins. Answer: A simple protein bound to DNA,
involved in the coiling of chromosomes