Chapter 3 - Molecular Genetics

Question 0

RNA

Answer 0

• single stranded
• adenine pairs with uracil
• guanine pairs with cytosine
• ribose sugar
• found in nucleus AND cytoplasm

Question 1

DNA

Answer 1

• double-stranded
• adenine pairs with thymine
• guanine pairs with cytosine
• deoxyribose sugar
• found in nucleus

Question 2

Plasmids

Answer 2

Small circular pieces of DNA that are found in bacteria. They replicate independently from chromosomal DNA

Question 3

Hybridization

Answer 3

Identifies the cells that contain introduced classmates with the desired gene. The gene can be identified by its unique DNA sequence meaning it will pair with a short single-stranded complementary DNA called hybridization probe

Question 4

Gel electrophoresis

Answer 4

This is used to separate DNA fragments. The separation is based on size and the charged molecules move through mesh like gel that separates them. All the nucleotides are negatively charged. So the DNA fragments migrate through gel at a rate that is inversely proportional to their size meaning the bigger fragment stay at the top of the smaller ones moved to the bottom of

Question 5

Chargaff rule

Answer 5

• discovered that nitrogenous bases in DNA always occur in exact ratios
• adenine matches the number of thymine
• cytosine matches the number of guanine

Question 6

Codons

Answer 6

• A group of three base pairs that code for an individual amino acid
• start codon is a AUG
• stop codons are UGA, UAA

Question 7

Anti-codons

Answer 7

• a triplet of complementary bases that is able to bind to mRNA codon’s that code for tRNAs specific amino acid
• example: a tRNA that is linked to a serine pairs with codon 5’ AUG 3’ in mRNA. The anti-codon of the tRNA that pairs with this codon is 3’ UCA 5’