1.3 Gene Expression

Question 1

alternative RNA splicing

Answer 1

particular exons of a gene may be included within or excluded from the final processed messenger RNA (mRNA)

Question 2

amino acid

Answer 2

unit of polypeptide structure

Question 3

anticodon

Answer 3

sequence of three bases on tRNA that codes for a specific amino acid

Question 4

attachment site

Answer 4

site on a transfer RNA molecule to which a specific amino acid binds

Question 5

codon

Answer 5

sequence of three bases on mRNA that codes for a specific amino acid

Question 6

environmental factors

Answer 6

factors such as diet, light and temperature that can interact with an organism’s genotype to affect its phenotype

Question 7

exon

Answer 7

coding sequence of DNA

Question 8

gene

Answer 8

section of DNA that codes for a protein

Question 9

gene expression

Answer 9

transcription and translation of a gene to synthesise proteins

Question 10

interactions

Answer 10

chemical attractions and bonding such as hydrogen bonds between amino acids, giving proteins their three-dimensional shape

Question 11

intron

Answer 11

non-coding sequence of DNA

Question 12

mature transcript

Answer 12

RNA transcript that has been spliced and processed ready for translation

Question 13

messenger RNA (mRNA)

Answer 13

carries a copy of the DNA code from the nucleus to the ribosome

Question 14

peptide bond

Answer 14

strong chemical link between amino acids in the primary structure of a polypeptide

Question 15

phenotype

Answer 15

outward appearance of an organism

Question 16

polypeptide

Answer 16

short strand of amino acids

Question 17

primary transcript

Answer 17

molecule made when DNA is transcribed

Question 18

ribose

Answer 18

sugar that forms part of an RNA nucleotide

Question 19

ribosomal RNA (rRNA)

Answer 19

type of RNA that makes up ribosomes

Question 20

ribosome

Answer 20

site of protein synthesis composed of rRNA and protein

Question 21

RNA

Answer 21

ribonucleic acid; several forms of single-stranded nucleic acid that are involved in protein synthesis

Question 22

RNA polymerase

Answer 22

enzyme which unwinds and unzips DNA and adds complementary nucleotides to form a primary transcript

Question 23

RNA splicing

Answer 23

joining of exons following the removal of introns from a primary transcript

Question 24

start codon

Answer 24

first codon of a messenger RNA transcript translated by a ribosome

Question 25

stop codon

Answer 25

codon within messenger RNA that signals a termination of translation into proteins

Question 26

transcription

Answer 26

copying of DNA sequence to make a primary transcript

Question 27

transfer RNA (tRNA)

Answer 27

transfers specific amino acids to the mRNA on the ribosomes

Question 28

translation

Answer 28

production of a polypeptide at a ribosome using information encoded in mRNA

Question 29

uracil (U)

Answer 29

RNA base not found in DNA; pairs with adenine in transcription and translation