molecular genetics

Question 1

Gene expression

Answer 1

Genes controlled the expression of inherited traits that are passed on from the parent to offspring

A gene is expressed when it directs the synthesis of a protein in a cell

Question 2

Transcription

Answer 2

• The process of copying genetic information from DNA to RNA
• DNA unzips
• RNA polymerase helps free RNA bases attach to exposed bases on DNA according to the base pairing rules

G & C , T & A, A & U

• mRNA detached from the DNA molecule and leaves the nucleus through nuclear pores

Question 3

Promoters

Answer 3

Sequence of DNA located before a gene starts

Question 4

Terminators

Answer 4

Sequence of DNA located after the end of a gene

Signals the end of transcription

Question 5

Exons

Answer 5

Hold the information for making a protein (cut out after transcription)

Question 6

Introns

Answer 6

Help regulate the expression of a gene
(Cut out after transcription)

Question 7

Translation

Answer 7

Amino acids are assembled by ribosomes to form a polypeptide chain

Once in the cytoplasm mRNA attaches to a ribosome

Every group of three bases of RNA is called a codon and codes for a particular amino acid

There’s often more than one codon for one amino acid

There are three base codes for stop which marks the end of the polypeptide chain