L2

Question 1

DNA –> ? –> ?

Answer 1

DNA replicates and is transcribed into pre-mRNA, spliced into mRNA, and translated into protein

Translation happens occurs outside nucleus to avoid replicating selfish transposons

Question 2

Exon

Answer 2

coding region - specifies amino acid sequence of protein

Question 3

Intron

Answer 3

non-coding region not translated into protein - transcribed to pre-mRNA and then removed by splicing during processing to mature mRNA

Question 4

Microsatellites

Answer 4

repeats of the same letters - can signal genetic relatedness as v prone to mutation

Question 5

Consequences of mutations during mitosis

Answer 5

• not drastic (other cells without mutations)
• increase with age as selection on repair mechanisms decreases
• can be predisposed to mutations

Question 6

Mutations during meiosis

Answer 6

Crossing over/recombination not accidental! Facilitated by Spo11 protein which initiates double stranded breaks and initiates crossing over

Question 7

Epigenetics

Answer 7

• Mechanisms of inheritance that do not include the DNA sequence
• Interaction among genes and between genes and env. lead to given development and phenotype

Question 8

Chromatin

Answer 8

complex of DNA and protein in eukaryotic cells

• constrains size of DNA molecule as needs to fit into chromatin
• changes in chromatin structure brought about by methylation and acetylation of nucleosome proteins

Question 9

4 epigenetic mechanisms

Answer 9

• DNA methylation and gene switching (make DNA unable to bind to RNA transferase)
• make DNA inaccessible/impossible for proteins to bind
• alternative splicing introns and exons to create alternative proteins
• disrupt translation to influence protein production