Unit 1 Biology (Edexcel IAL): Nucleic acids
UPDATED ACTUAL Questions and
CORRECT Answers
What are nucleotides? - CORRECT ANSWER- Molecules that carry the information needed
to form new cells
What is DNA? - CORRECT ANSWER- Deoxyribonucleic acid
Where is DNA found? - CORRECT ANSWER- In chromosomes of the nucleus of cells
What is the structure of DNA? - CORRECT ANSWER- Polymers consisting of nucleotide
monomers
Nucleotide consists of:
- Pentose sugar (deoxyribose)
- Phosphate group (phosphoric acid)
- Nitrogenous base
What is RNA? - CORRECT ANSWER- Ribonucleic acid
What is the structure of RNA? - CORRECT ANSWER- Polymers consisting of nucleotide
monomers
Nucleotide consists of:
- Pentose sugar (ribose)
- Phosphate group (phosphoric acid)
- Nitrogenous base
What is the difference between deoxyribose and ribose? - CORRECT ANSWER-
Deoxyribose contains 1 less oxygen atom
, What are the purine bases? - CORRECT ANSWER- Bases with 2 nitrogen containing rings:
adenine and guanine
What are the pyrimidine bases? - CORRECT ANSWER- Bases with 1 nitrogen containing
ring: cytosine, thymine, and uracil
What are the base pairings in DNA? - CORRECT ANSWER- A - T
G-C
What are the base pairings in RNA? - CORRECT ANSWER- A - U
G-C
What forms the backbone of DNA and RNA? - CORRECT ANSWER- Pentose sugar and
phosphate group
How are nucleotides formed? - CORRECT ANSWER- - Sugar and base join in a
condensation reaction to form a nucleoside and a molecule of water
- Phosphate base joins via a phosphoester bond between the -OH group on phosphoric acid
and the -OH group on the pentose sugar to create a nucleotide and a molecule of water
How are polynucleotides formed? - CORRECT ANSWER- - Two nucleotides join in a
condensation reaction with a phosphodiester bond
- Each chain has a 5' and 3' end
How is the double helix of DNA formed? - CORRECT ANSWER- - Polynucleotide strand
has a second, antiparallel chain running in opposite direction with complimentary base
pairings
- Two strands held together by hydrogen honds
- A-T has 2 hydrogen honds
UPDATED ACTUAL Questions and
CORRECT Answers
What are nucleotides? - CORRECT ANSWER- Molecules that carry the information needed
to form new cells
What is DNA? - CORRECT ANSWER- Deoxyribonucleic acid
Where is DNA found? - CORRECT ANSWER- In chromosomes of the nucleus of cells
What is the structure of DNA? - CORRECT ANSWER- Polymers consisting of nucleotide
monomers
Nucleotide consists of:
- Pentose sugar (deoxyribose)
- Phosphate group (phosphoric acid)
- Nitrogenous base
What is RNA? - CORRECT ANSWER- Ribonucleic acid
What is the structure of RNA? - CORRECT ANSWER- Polymers consisting of nucleotide
monomers
Nucleotide consists of:
- Pentose sugar (ribose)
- Phosphate group (phosphoric acid)
- Nitrogenous base
What is the difference between deoxyribose and ribose? - CORRECT ANSWER-
Deoxyribose contains 1 less oxygen atom
, What are the purine bases? - CORRECT ANSWER- Bases with 2 nitrogen containing rings:
adenine and guanine
What are the pyrimidine bases? - CORRECT ANSWER- Bases with 1 nitrogen containing
ring: cytosine, thymine, and uracil
What are the base pairings in DNA? - CORRECT ANSWER- A - T
G-C
What are the base pairings in RNA? - CORRECT ANSWER- A - U
G-C
What forms the backbone of DNA and RNA? - CORRECT ANSWER- Pentose sugar and
phosphate group
How are nucleotides formed? - CORRECT ANSWER- - Sugar and base join in a
condensation reaction to form a nucleoside and a molecule of water
- Phosphate base joins via a phosphoester bond between the -OH group on phosphoric acid
and the -OH group on the pentose sugar to create a nucleotide and a molecule of water
How are polynucleotides formed? - CORRECT ANSWER- - Two nucleotides join in a
condensation reaction with a phosphodiester bond
- Each chain has a 5' and 3' end
How is the double helix of DNA formed? - CORRECT ANSWER- - Polynucleotide strand
has a second, antiparallel chain running in opposite direction with complimentary base
pairings
- Two strands held together by hydrogen honds
- A-T has 2 hydrogen honds
