Genetics, Biodiversity and Classification

• What do both DNA and RNA carry?

  Information
• What is the primary function of DNA?

  To hold genetic information
• What is the role of RNA in relation to DNA?

  To transfer genetic information from DNA to ribosomes
• What are nucleotides composed of?

  Pentose sugar, nitrogen base, and phosphate group
• What are the two types of nucleic acids mentioned?

  DNA and RNA
• What are the components of a DNA nucleotide?

  Deoxyribose, phosphate group, and one of the bases adenine, cytosine, guanine, or thymine
• What are purine bases?

  Bases with double ring structures, such as adenine and guanine
• What are the components of an RNA nucleotide?

  Ribose, phosphate group, and one of the bases adenine, cytosine, guanine, or uracil
• What is the structure of pyrimidine bases?

  Single ring structure
• How do nucleotides join together?

  By phosphodiester bonds formed in condensation reactions
• What is the structure of a DNA molecule?

  A double helix composed of two polynucleotides
• What is the genetic code?

  The order of bases on DNA that consists of triplets coding for amino acids
• What is a codon?

  A triplet of bases coding for a particular amino acid
• What is a gene?

  A sequence of bases on a DNA molecule coding for a sequence of amino acids
• What is the locus of a gene?

  The location of a gene
• What are introns and exons?

  Introns are non-coding sections of DNA, while exons are coding regions
• How many nucleotide bases code for how many different amino acids?

  Four nucleotide bases code for 20 different amino acids
• What does it mean that the genetic code is degenerate?

  More than one triplet codes for the same amino acid
• What are mutations?

  Changes in the base sequence of DNA
• What are start and stop codons?

  Codons that signal the beginning and end of protein synthesis
• Where is DNA found in eukaryotic cells?

  In the nucleus
• How is eukaryotic DNA structured?

  Long and linear, associated with histones to form chromosomes
• How many chromosomes do humans have?

  46 chromosomes
• What is a homologous pair of chromosomes?

  Two chromosomes that carry the same genes but may have different alleles
• What determines the sex of an individual?

  The 23rd chromosome
• What is an allele?

  An alternative form of the same gene
• How many alleles does an individual inherit for every gene?

  Two alleles
• What are the two stages of protein synthesis?

  Transcription and translation
• Where does transcription occur?

  In the nucleus
• What is the role of mRNA?

  To carry the genetic code from DNA to ribosomes
• What is the structure of mRNA?

  A long single strand complementary to DNA
• What is a codon in mRNA?

  A set of three bases
• What is the structure of tRNA?

  A small molecule folded into a cloverleaf shape
• What is the function of the anti-codon in tRNA?

  To match with the codon on mRNA
• What happens during transcription?

  A section of DNA is transcribed into mRNA
• What breaks the hydrogen bonds during transcription?

  An enzyme
• What is the antisense strand?

  The DNA strand used as a template to make mRNA
• What is the role of RNA polymerase during transcription?

  To catalyze the formation of phosphodiester bonds
• What happens to the DNA after RNA polymerase moves away?

  The DNA rejoins
• What is pre-mRNA?

  The initial RNA transcript that contains introns and exons