DNA, Genes & chromosomes

Question 1

Structure of DNA

Answer 1

Made up of deoxyribose suagr, a phosphate group, and 1 of four organic bases (A, C, G, T).
Double stranded, & hydrogen bonds between bases form helix shape

Question 2

Structure of RNA

Answer 2

Made up of a ribose sugar, a phospate group, and 1 of four organic bases (A, C, G, U).
Single stranded

Question 3

Which bases are purine & which are pyrimidine?

Answer 3

Purine (double ring) = adenine, guanine
Pyrimindine (single ring) = cytosine, thymine, uracil

Question 4

Difference in DNA between eukaryote and prokaryote

Answer 4

Eukaryote = found in nucleus, long & linear. Associated with histone proteins to form chromosomes. Mitochondria & chloroplasts contain prokaryotic-like DNA.
Prokaryote: short & circular. Not associated with proteins

Question 5

Features of genetic code

Answer 5

• Non-overlapping= each triplet is only read once.
• Degenerate= more than 1 triplet codes for the same amino acid (64 possible for 20 amino acids)
• Universal= same bases & sequences used by all species